Home Design and synthesis of quinazolinyl acetamides for their analgesic and anti-inflammatory activities
Article Publicly Available

Design and synthesis of quinazolinyl acetamides for their analgesic and anti-inflammatory activities

  • Veerachamy Alagarsamy EMAIL logo , Viswas Raja Solomon , Mohaideen Thasthagir Sulthana , Meduri Satyasai Vijay and Bandi Narendhar
Published/Copyright: June 23, 2015
Download Article (PDF)
Become an author with De Gruyter Brill
Author Information Explore this Subject
Zeitschrift für Naturforschung B
From the journal Zeitschrift für Naturforschung B Volume 70 Issue 8

Abstract

A variety of novel 2-(substituted)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamides were synthesized by the reaction of 2-chloro-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide with various amines. The starting material, 2-chloro-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide, was synthesized from anthranilic acid by the multistep process. The title compounds were investigated for analgesic, anti-inflammatory, and ulcerogenic index activities. Among those, the compound 2-(ethylamino)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V9) showed most potent analgesic and anti-inflammatory activities of the series and it is moderately more potent compared to the reference standard diclofenac sodium. Interestingly, the test compounds showed only mild ulcerogenic potential compared to aspirin.

Keywords: analgesic; anti-inflammatory; quinazoline; ulcer index

1 Introduction

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed for the treatment of acute and chronic inflammation, pain, and fever. The most of NSAIDs act via inhibition of cyclooxygenase, thus preventing prostaglandin biosynthesis. However, this mechanism of action is also responsible for their main undesirable effects, gastrointestinal (GI) ulceration, and, less frequently, nephrotoxicity. The increase in hospitalization and deaths due to GI-related disorders parallels the increased use of NSAIDs. Therefore, the discovery of new safer anti-inflammatory drugs represents a challenging goal for such a research area [1–4]. In our going medicinal chemistry research program, we found that quinazolines and condensed quinazolines exhibit potent central nervous system activities including analgesic, anti-inflammatory [5–7], and anticonvulsant behavior [8]. Quinazolin-4(3H)-ones with C-2 and N-3 substitution are reported to possess significant analgesic, anti-inflammatory [9, 10], and anticonvulsant activities [11]. Earlier we have documented some lead 2-benzylamino-3-(2-subsituted amino)quinazolin-4(3H)-one (Fig. 1, I) [12], 1-(2-phenylquinazolin-3-yl-4(3H)-one)-3-substituted thiourea (Fig. 1, II), 2,3-disubstituted quinazolines that exhibited good analgesic and anti-inflammatory activities [5, 13, 14]. The present work is an extension of our ongoing efforts towards the development and identification of new molecules for analgesic and anti-inflammatory activities with minimal gastrointestinal ulceration side effects. With this background in the present study, we have synthesized a series of 2-(substituted)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamides. The synthesized compounds were tested for their analgesic, anti-inflammatory, and ulcerogenic index behavior.

Fig. 1: Lead molecules of quinazolin-4-ones.
Fig. 1:

Lead molecules of quinazolin-4-ones.

2 Results and discussion

The synthetic route depicted in Scheme 1 outlines the chemistry part of the present work. The key intermediate 3-amino-2-phenylquinazoline-4-(3H)-one (4) was synthesized by a straightforward method; anthranilic acid (1) was treated with benzoyl chloride (2) in the presence of pyridine to give benzoxazin-4-one (3) which was condensed with hydrazine hydrate in ethanol to yield the desired 3-amino-2-phenylquinazoline-4-(3H)-one (4). The 2-chloro-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (6) was prepared by the reaction between 4 and chloroacetyl chloride (5) in dry dioxane in the presence of triethylamine. The IR spectrum of 6 showed intense peaks at 3189 cm−1 for NH, 1689, 1643 cm−1 for carbonyl (C=O), 1607 cm−1 for (C=N), and 700 cm−1 for (C–Cl). The 1H NMR spectrum of 6 showed a singlet at δ = 3.89 ppm due to a CH2 group and for aromatic protons in the range δ = 7.45–7.73 ppm. The title compounds, 2-(substituted)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide V1–V10, were obtained in fair to good yield through the nucleophilic displacement of the chloride substituted of 6 with a variety of amines, using dioxane as solvent. The formation of title compounds is indicated by the disappearance of the C–Cl stretching peak of the starting material and the appearance of NH at 3380, 3360 cm−1 in the IR spectra of the compounds; NMR spectra showed signals for substituents at C-3 and a singlet around δ = 8.5 ppm due to NH, and a multiplet at δ = 7.12–7.78 ppm was observed for aromatic protons. The mass spectra of the title compounds showed molecular ion peaks corresponding to their molecular formulae. In the mass spectrum of compounds V1–V10, a common peak at m/z = 144 corresponding to a quinazolin-4-one moiety appeared. The 35Cl/37Cl isotope peaks were observed in the mass spectra of compound 6, confirming the presence of a chlorine atom in the compounds. The relative intensities of these 35Cl/37Cl peaks in comparison with the [M]+ peak were in the ratio of 1:3. Elemental (C, H, N) analyses satisfactorily confirmed elemental composition and purity of the synthesized compounds.

Scheme 1: Synthesis of 2-(substituted)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamides. Reagents and conditions: (a) pyridine, room temperature, 30 min; (b) hydrazine hydrate, ethanol reflux, 3 h; (c) chloroacetyl chloride (5); (d) triethylamine, dioxane, room temperature, 30 min, then 1 h at reflux temperature.
Scheme 1:

Synthesis of 2-(substituted)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamides. Reagents and conditions: (a) pyridine, room temperature, 30 min; (b) hydrazine hydrate, ethanol reflux, 3 h; (c) chloroacetyl chloride (5); (d) triethylamine, dioxane, room temperature, 30 min, then 1 h at reflux temperature.

Evaluation of analgesic activity was performed by the tail-immersion technique using Wistar albino mice (Table 1). The results of analgesic testing indicate that the test compounds exhibited moderate analgesic activity at 30 min of reaction time and an increase in activity at 1 h which reached a peak level at 2 h, and declining activity was observed at 3 h (Table 1). Compound V9 with 1-ethyl substituent showed good activity (43 %); when the ethyl group was replaced by a morpholinyl group (V4), the activity was retained (40 %), whereas the piperazinyl substituent (V3) exhibited a similar potency (38 %). (Substituted) aryl substituents showed a decrease in activity compared to the aliphatic and heteroaliphatic substituents. Compound V9 emerged as the most active analgesic agent and it is equipotent compared to the reference standard diclofenac.

Table 1

Analgesic activity of synthesized compounds (V1–V10) by the tail-flick technique.

CompoundPercentage analgesic activitya
0.5 h1 h2 h3h
V123 ± 1.05b24 ± 1.53b28 ± 1.21b26 ± 1.53b
V221 ± 1.46b22 ± 1.09b25 ± 1.43b23 ± 1.03b
V332 ± 1.43b35 ± 1.17c38 ± 1.91c29 ± 1.15b
V434 ± 1.62b37 ± 1.41c40 ± 1.91c30 ± 1.32b
V529 ± 1.51b31 ± 1.30b36 ± 1.41c28 ± 1.32b
V628 ± 1.13b29 ± 1.21b32 ± 1.06c26 ± 1.44b
V721 ± 1.41b23 ± 1.62b24 ± 1.81b21 ± 1.14b
V825 ± 1.11b27 ± 1.06b30 ± 1.20b26 ± 1.73b
V935 ± 1.28c41 ± 1.42c53 ± 1.05c31 ± 1.53b
V1030 ± 1.51b33 ± 1.26c36 ± 1.51c29 ± 1.63b
Control2 ± 0.234 ± 0.304 ± 0.292 ± 0.51
Diclofenac38 ± 1.23c43 ± 1.42c46 ± 1.08c35 ± 1.15b

aData expressed as mean ± SD from six different experiments done in duplicate; significance levels bp < 0.5 and cp < 0.01 as compared to the respective control; control refers to no treatment (vehicle only).

Anti-inflammatory activity was evaluated by the carrageenan-induced paw edema test in rats [15]. The anti-inflammatory activity data (Table 2) indicated that all the test compounds protected rats from carrageenan-induced inflammation moderately at 30 min of reaction time with increased activity at 1 h that reached a peak level at 2 h. The decline in activity was observed at 3 h. Compound V9 showed the most potent anti-inflammatory activity of the series, and it is moderately more potent compared to the reference standard diclofenac sodium.

The most potent compounds of the series were evaluated for ulcer index studies. Compared to the reference standards aspirin (ulcer index 1.73) and diclofenac (ulcer index 1.65), the test compounds exhibited about 35 %–50 % of the ulcer index of the reference standards. The most active compound V9 exhibited the smallest ulcer index (0.51), which is about one third of the ulcer index of reference standards aspirin and diclofenac.

Table 2

Anti-inflammatory activity of synthesized compounds (V1–V10) determined by carrageenan-induced paw edema test in rats.

CompoundPercentage protectiona
30 min1 h2 h3 h
V121 ± 1.31c23 ± 1.23c25 ± 1.21c22 ± 1.62b
V220 ± 1.38c21 ± 1.54c23 ± 1.84d20 ± 1.26b
V331 ± 1.26c31 ± 1.84d34 ± 1.04d28 ± 1.26b
V430 ± 1.27b35 ± 1.48c39 ± 1.23c29 ± 1.23b
V526 ± 1.72b28 ± 1.18c32 ± 1.53c25 ± 1.31b
V625 ± 1.72b26 ± 1.32b30 ± 1.16c23 ± 1.42b
V720 ± 1.12b21 ± 1.53b21 ± 1.27c19 ± 1.73b
V821 ± 1.16b22 ± 1.42b22 ± 1.93b20 ± 1.53b
V933 ± 1.16b40 ± 1.73b42 ± 1.52b32 ± 1.20b
V1026 ± 1.27b29 ± 1.23b30 ± 1.42b25 ± 1.16b
Control5.1 ± 0.296.1 ± 0.275.7 ± 0.323.2 ± 0.93
Diclofenac32 ± 0.63b38 ± 1.58b39 ± 1.97b33 ± 0.93b

aData expressed as mean ± SD from six different experiments done in duplicate; significance levels bp < 0.5, cp < 0.01, and dp < 0.001 as compared to the respective control; control refers to no treatment (vehicle only).

In our earlier studies [5, 12–14], we observed that the presence of aryl and methyl groups at C-2 position and various functional groups at N-3 substitution exhibited more analgesic and anti-inflammatory activities. In this continuation, N-3 modification was made by substitution in such a way to increase the lipophilicity of the molecule. The placement of the acetamide group enhanced the analgesic and anti-inflammatory activities. The most active compound of the C-2 benzylamino series was 2-(benzylamino)-3-((3-phenylallylidene)amino)quinazolin-4(3H)-one (Fig. 1, I), which exhibited 50 % analgesic and 44 % anti-inflammatory activity at the dose of 10 mg kg−1, at the reaction time of 2 h [12]. In the C-2 phenyl series, 1-diethyl-3-(2-phenylquinazolin-3-yl-4(3H)-one)thiourea (Fig. 1, II) showed 44 % analgesic and 38 % anti-inflammatory activity at the dose of 10 mg kg−1, at the reaction time of 2 h [13]. This set of compounds showed moderately higher analgesic and anti-inflammatory activities (V1–V9), compound V9 showed 53 % analgesic and 42 % anti-inflammatory activity at the dose of 10 mg kg−1, at the reaction of 2 h. Interestingly, these compounds showed one third of ulcer index of the reference NSAIDs aspirin and diclofenac. Hence this series could be developed as a novel class of analgesic and anti-inflammatory agents.

3 Conclusion

In the present study, the synthesis of a new series of 2-(substituted)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamides (V1–V10) has been described. The results of the analgesic and anti-inflammatory activities showed a moderate enhancement of activity. The compound 2-(ethylamino)-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V9) emerged as the most active compound. Hence this series could be developed as a novel class of analgesic and anti-inflammatory agents. Further structural modification is planned to obtain compounds with increased analgesic and anti-inflammatory activities with minimal ulcerogenic behavior.

4 Experimental section

4.1 General

Melting points were determined in open capillary tubes on a Thomas Hoover melting point apparatus (Thomas Hoover, Philadelphia, PA, USA) and are uncorrected. IR spectra were recorded in KBr on a Shimadzu FT-IR 8300 spectrometer (cm−1) (Bio Engineering, Wald, Switzerland), mass spectra on a MASPEC 629 mass spectrometer (Mass Spec, Tokyo, Japan) at 70 eV, and NMR spectra on a varian 300 MHz spectrometer (Pacific Northwest, Richland, WA, USA), using tetramethylsilane as internal standard. Elemental analyses were performed on a Carlo Erba 1108 (Heraeus, Hanau, Germany). The progress of the reaction was monitored on readymade silica gel plates (Merck, Whitehouse Station, NJ, USA) using benzene–chloroform–methanol (2:1:0.5) as a solvent system. Iodine was used as a developing agent. Chromatographic purification was performed over silica gel (200–430 mesh). All chemicals and reagents used in the synthesis were obtained from Aldrich (Sigma-Aldrich, St. Louis, MO, USA), Lancaster (Alfa Aesar, Johnson Matthey Company, Ward Hill, MA, USA), or Spectrochem Pvt Ltd (Mumbai, India) and were used without further purification.

4.2 Synthesis of 2-phenyl-3,1-benzoxazin-4-one (3)

To a solution of anthranilic acid 1 (1.37 g; 0.1 mol) dissolved in pyridine (60 mL) benzoyl chloride (2) (1.40 g, 0.2 mol) was added. The mixture was stirred for 0.5 h followed by treatment with 5 % sodium bicarbonate (15 mL). The separated solid was recrystallized from ethanol. Yield 80 %; m.p. 118–120 °C. – IR (KBr): v = 3350 (NH), 1780 (C=O) 1680 (cyclic C=O), and 1620 (C=N) cm−1. – 1H NMR (CDCl3): δ = 6.81–6.84 (m, 3H, Ar-H), 6.95–6.97 (d, J = 7.5 Hz, 2H), 7.02–7.04 (m, 3H, Ar-H), 7.51–7.52 (d, J = 2.0 Hz, 1H). – 13C NMR (CDCl3): δ = 115.43, 120.79, 126.35, 127.45, 128.53, 128.75, 130.87, 131.05, 134.52, 153.85, 155.89, 158.95. – MS (EI, 70 eV): m/z (%) = 223 (100) [M]+. – C14H9NO2: calcd. C 75.33, H 4.03, N 6.27; found: C 75.37, H 3.99, N, 6.31.

4.3 Synthesis of 3-amino-2-phenylquinazolin-4-(3H)-one (4)

A mixture of 2-phenyl-3,1-benzoxazin-4-one 3 (2.23 g, 0.05 mol) and hydrazine hydrate (0.30 mL, 0.05 mol) in ethanol was refluxed for 3 h and cooled. The separated solid was recrystallized from ethanol. Yield 85 %; m.p. 195–196 °C. – IR (KBr): v = 3300 (NH2), 1680 (cyclic C=O), 1620 (C=N), and 1600 (C=C) cm−1. – 1H NMR (CDCl3): δ = 4.52 (s, 2H, NH2), 6.82–6.85 (m, 3H, Ar-H), 6.94–6.96 (d, J = 7.5 Hz, 2H), 7.03–7.05 (m, 3H, Ar-H), 7.49–7.50 (d, J = 2.0 Hz, 1H). – 13C NMR (CDCl3): δ = 118.54, 120.79, 126.35, 127.45, 128.63, 128.54, 130.75, 131.05, 134.52, 153.61, 155.89 159.75. – MS (EI, 70 eV): m/z (%) = 237 (100) [M]+. – C14H11N3O: calcd. C 70.88, H 4.64, N 17.72; found C 70.92, H 4.67, N 17.68.

4.4 Synthesis of 2-chloro-N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (6)

3-Amino-2-phenylquinazoline 4 (2.23 g, 0.01 mol) was dissolved in dry dioxane (20 mL). To this mixture triethylamine (1.01 g, 0.01 mol) and chloroacetyl chloride (5) (1.12 g, 0.01 mol) were added and stirred at room temperature for 30 min. The stirring was continued for 1 h with heating. Then the reaction mixture was poured into ice water and extracted with ether. The ether extract were washed with 3 % sodium bicarbonate solution and dried over anhydrous sodium sulfate, which upon evaporation afforded the product. Yield 83 %, – m.p. 140–142 °C; Rf = 0.31 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3189 (NH), 1689 (C=O), 1643 (C=O), 1607 (C=N), 700 (C–Cl) cm−1. – 1H NMR (CDCl3): δ = 3.89 (s, 2H, CH2), 7.45–7.48 (m, 3H, Ar-H), 7.55–7.58 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 2H), 7.71–7.73 (m, 1H, Ar-H), 9.52 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 43.85, 118.89, 120.81, 126.35, 127.73, 128.72, 130.78, 131.16, 134.55, 153.68, 155.92, 159.75; 162.79, 163.85. – MS (EI, 70 eV): m/z (%) = 314 (100) [M]+; 316 (78) [M + 2]. – C16H12N3O2Cl: calcd C 61.25, H 3.86, N 13.39; found C 61.55, H 3.77, N 13.23.

4.5 Synthesis of 2-(4-chlorophenylamino)- N-(4-oxo-2-phenylquinazolin-3-(3H)-yl)acetamide (V1)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and 4-chloroaniline (1.27 g, 0.01 mol) in dioxane (15 mL) was refluxed for 11 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 85 %; m.p. 154–156 °C; Rf = 0.35 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3380 (NH), 1726 (C=O), 3195 (NH), 1700 (C=O), 1614 (C=N), 638 (C–Cl) cm−1. – 1H NMR (CDCl3): δ = 3.82 (s, 2H, CH2), 6.75–6.77 (d, J = 7.5 Hz, 2H), 7.05–7.06 (d, J = 2.0 Hz, 1H), 7.12–7.15 (m, 3H, Ar-H), 7.45–7.48 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.22–8.23 (m, 1H, Ar-H), 8.54 (br s, 1H, NH), 8.65 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 55.35, 113.89, 118.59, 120.81, 121.33, 126.25, 127.83, 128.45, 128.75, 130.78, 131.16, 134.45, 141.85, 153.68, 155.92, 159.75, 162.79, 168.53. – MS (EI, 70 eV): m/z (%) = 405 (100) [M]+. – C22H17N4O2Cl: calcd. C 65.27, H 4.23, N 13.84; found C 65.55, H 4.04, N 13.73.

4.6 Synthesis of 2-(4-nitrophenylamino)- N-(4-oxo-2-phenylquinazolin-3-(3H)-yl) acetamide (V2)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and 4-nitroaniline (1.38 g, 0.01 mol) in dioxane (15 mL) was refluxed for 12 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 75 %; m.p. 170–172 °C; Rf = 0.33 (benzene–chloroform–methanol, 2:1:0.5). IR (KBr): 3360 (NH), 3240 (NH), 1710 (C=O), 1631 (C=O), 1597 (C=N), 1556 (NO2) cm−1. – 1H NMR (CDCl3): δ = 3.85 (s, 2H, CH2), 6.77–6.79 (d, J = 7.5 Hz, 2H), 7.05–7.06 (d, J = 2.0 Hz, 1H), 7.15–7.17 (m, 3H, Ar-H), 7.45–7.48 (m, 3H, Ar-H), 7.89–7.91 (d, J = 8.0 Hz, 1H), 8.22–8.23 (m, 1H, Ar-H), 8.64 (br s, 1H, NH), 8.75 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 53.85, 113.89, 118.51, 120.22, 120.79, 120.98, 126.75, 127.83, 128.85, 128.93, 130.78, 131.16, 134.55, 135.89, 152.85, 153.68, 155.92, 159.75; 162.79, 169.75. – MS (EI, 70 eV): m/z (%) = 416 (100) [M]+. – C22H17N5O4: calcd. C 67.35, H 7.02, N 16.86; found C 67.55, H 7.04, N, 16.73.

4.7 Synthesis of 2-(piperazinyl)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V3)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and piperazine (0.86 g, 0.01 mol) in dioxane (15 mL) was refluxed for 11 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 70 %, – m.p. 205–207 °C; Rf = 0.36 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3402 (NH), 3217 (NH), 1639 (C=O), 1705 (C=O), 1593 (C=N) cm−1. – 1H NMR (CDCl3): δ = 2.45–2.47 (m, 4H, CH2 piperazinyl), 2.63–2.65 (m, 4H, CH2 piperazinyl), 3.25 (s, 2H, CH2), 6.68–6.70 (d, J = 7.5 Hz, 2H), 7.06–7.07 (d, J = 2.0 Hz, 2H), 7.15–7.18 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.22–8.23 (m, 1H, Ar-H), 8.45 (br s, 1H, NH), 8.67 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 44.35, 53.75, 57.65, 118.89, 120.81, 126.35, 127.73, 128.72, 130.78, 131.16, 134.55, 153.68, 155.92, 159.75, 162.79, 168.85. – MS (EI, 70 eV): m/z (%) = 364 (100) [M]+. – C20H21N5O2: calcd. C 66.10, H 5.82, N 19.27; found C 66.55, H 5.87, N 19.84.

4.8 Synthesis of 2-(morpholinyl)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl) acetamide (V4)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and morpholine (0.87 mL, 0.01 mol) in dioxane (15 mL) was refluxed for 12 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 70 %; m.p. 127–129 °C; Rf = 0.35 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3402 (NH), 3217 (NH), 1639 (C=O), 1705 (C=O), 1593 (C=N) cm−1. – 1H NMR (CDCl3): δ = 2.30–2.33 (m, 4H, CH2 morpholinyl), 3.23 (s, 2H, CH2), 3.53–3.55 (m, 4H, CH2 morpholinyl), 6.65–6.67 (d, J = 7.5 Hz, 2H), 7.07–7.08 (d, J = 2.0 Hz, 2H), 7.15–7.18 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.22–8.23 (m, 1H, Ar-H), 8.45 (br s, 1H, NH), 8.67 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 52.85, 58.79, 64.85, 118.89, 120.81, 126.35, 127.73, 128.72, 130.78, 131.16, 134.55, 153.68, 155.92, 159.75; 162.79, 168.75. – MS (EI, 70 eV): m/z (%) = 364 (100) [M]+. – C20H20N4O3: calcd. C 67.58, H 7.08, N 19.70; found: C 67.55, H 7.04, N 19.65.

4.9 Synthesis of 2-(4-methoxyphenylamino)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V5)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and 4-methoxyaniline (1.23 g, 0.01 mol) in dioxane (15 mL) was refluxed for 12 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 78 %; m.p. 186–188 °C; Rf = 0.41 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): v = 3350 (NH), 3240 (NH), 1700 (C=O), 1660 (C=O), 1596 (C=N) cm−1. – 1H NMR (CDCl3): δ = 3.73 (s, 3H, OCH3), 3.82 (s, 2H, CH2), 6.22–6.24 (d, J = 7.5 Hz, 2H), 6.45–6.47 (d, J = 1.5 Hz, 2H), 6.65–6.67 (d, J = 7.5 Hz, 2H), 7.11–7.12 (d, J = 2.0 Hz, 2H), 7.35–7.38 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.25–8.27 (m, 1H, Ar-H), 8.45 (br s, 1H, NH), 8.65 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 54.85, 55.76, 114.45, 115.75, 118.89, 120.81, 126.35, 127.73, 128.72, 130.78, 131.16, 134.55, 138.75, 148.85, 153.68, 155.92, 159.75, 162.79, 169.11. – MS (EI, 70 eV): m/z (%) = 401 (100) [M]+. – C23H20N4O3: calcd. C 67.58, H 7.08, N 19.70; found C 67.55, H 7.04, N 19.73.

4.10 Synthesis of 2-(3-methoxyphenylamino)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V6)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and 3-methoxyaniline (1.11 mL, 0.01 mol) in dioxane (15 mL) was refluxed for 11 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 80 %; m.p. 200–202 °C; Rf = 0.40 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3348 (NH), 3230 (NH), 1715 (C=O), 1655 (C=O), 1596 (C=N) cm−1. – 1H NMR (CDCl3): δ = 3.69 (s, 3H, OCH3), 3.82 (s, 2H, CH2), 5.97–5.99 (m, 2H, Ar-H), 6.11–6.13 (m, 1H, Ar-H), 6.93–6.95 (m, 1H, Ar-H), 6.65–6.67 (d, J = 7.5 Hz, 2H), 7.11–7.12 (d, J = 2.0 Hz, 2H), 7.35–7.38 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.23–8.25 (m, 1H, Ar-H), 8.55 (br s, 1H, NH), 8.68 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 54.35, 55.85, 96.89, 102.75, 104.98, 118.89, 120.81, 126.35, 127.73, 128.72, 129.44, 130.78, 131.16, 134.55, 148.53, 153.68, 155.92, 159.75, 161.53, 162.79, 168.85. – MS (EI, 70 eV): m/z (%) = 401 (100) [M]+. – C23H20N4O3: calcd. C 67.58, H 7.08, N 19.70; found C 67.55, H 7.04, N 19.73.

4.11 Synthesis of 2-(2-nitro phenylamino)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V7)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and 2-nitroaniline (1.38 g, 0.01 mol) in dioxane (15 mL) was refluxed for 11 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 87 %; m.p. 200–202 °C; Rf = 0.37 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3358 (NH), 3227 (NH), 1730 (C=O), 1675 (C=O), 1578 (C=N) cm−1. – 1H NMR (CDCl3): δ = 3.85 (s, 2H, CH2), 6.68–6.70 (d, J = 7.5 Hz, 2H), 6.76 (d, J = 2.0 Hz, 1H), 7.06–7.07 (d, J = 2.0 Hz, 2H), 7.15–7.18 (m, 3H, Ar-H), 7.26–7.28 (m, 2H, Ar-H), 7.49–7.51 (m, 1H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.22–8.23 (m, 1H, Ar-H), 8.45 (br s, 1H, NH), 8.67 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 56.22, 113.45, 117.53, 118.89, 120.81, 120.94, 126.35, 127.73, 128.72, 130.78, 131.16, 131.57, 134.55, 134.93, 137.65, 153.68, 155.92, 159.75, 162.79, 168.75. – MS (EI, 70 eV): m/z (%) = 415 [M]+. – C22H17N5O4: calcd. C 67.35, H 7.02, N 16.86; found C 67.41, H 7.11, N 16.81.

4.12 Synthesis of 2-(4-amino pyridinyl)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V8)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and 4-amino pyridine (0.94 g, 0.01 mol) in dioxane (15 mL) was refluxed for 11 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 86 %; m.p. 182–184 °C; Rf = 0.32 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3357 (NH), 3235 (NH), 1725 (C=O), 1687 (C=O), 1614 (C=N) cm−1. – 1H NMR (CDCl3): δ = 3.87 (s, 2H, CH2), 6.61–6.63 (m, 2H, Ar-H), 6.68–6.70 (d, J = 7.5 Hz, 2H), 7.06–7.07 (d, J = 2.0 Hz, 2H), 7.15–7.18 (m, 3H, Ar-H), 7.35 (m, 1H, Ar-H), 7.68–7.69 (d, J = 2.0 Hz, 1H), 8.08–8.09 (d, J = 2.0 Hz, 2H), 8.22–8.23 (m, 1H, Ar-H), 8.51 (br s, 1H, NH), 8.63 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 56.85, 108.71, 112.51, 118.89, 120.81, 126.35, 127.73, 128.72, 130.78, 131.16, 134.55, 137.42, 147.83, 153.68, 155.92, 158.53, 159.75, 162.79, 168.75. – MS (EI, 70 eV): m/z (%) = 372 (100) [M]+. – C21H17N5O2: calcd. C 67.91, H 4.61, N 18.86; found C 67.85, H 4.62, N 18.73.

4.13 Synthesis of 2-(ethylamino)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V9)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and ethylamine (0.56 mL, 0.01 mol) in dioxane (15 mL) was refluxed for 12 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 77 %; m.p. 162–164 °C; Rf = 0.39 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3335 (NH), 3235 (NH), 1715 (C=O), 1682 (C=O), 1611 (C=N) cm−1. – 1H NMR (CDCl3): δ = 0.95–0.97 (t, J = 7.5 Hz, 3H), 3.32 (s, 2H, CH2), 2.43–2.45 (m, 2H, CH2), 6.65–6.67 (d, J = 7.5 Hz, 2H), 7.07–7.08 (d, J = 2.0 Hz, 2H), 7.15–7.18 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.22–8.23 (m, 1H, Ar-H), 8.45 (br s, 1H, NH), 8.67 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 9.87, 22.54, 51.33, 54.35, 118.89, 120.81, 126.35, 127.73, 128.72, 130.78, 131.16, 134.55, 153.68, 155.92, 159.75; 162.79, 168.89. – MS (EI, 70 eV): m/z (%) = 323 (100) [M]+. – calcd. C18H18N4O2: C 67.58, H 7.08, N 19.70; found C 67.55, H 7.04, N 19.73.

4.14 Synthesis of 2-(2-methylamino)- N-(4-oxo-2-phenylquinazolin-3(3H)-yl)acetamide (V10)

A mixture of compound 6 (3.13 g, 0.01 mol), anhydrous potassium carbonate (100 mg), and 2-methylaniline (1.07 mL; 0.01 mol) in dioxane (15 mL) was refluxed for 12 h. The reaction mixture was then poured into crushed ice. The solid obtained was filtered, washed with water, dried, and recrystallized from the benzene–ethanol mixture (50:50). Yield 70 %; m.p. 190–192 °C; Rf = 0.38 (benzene–chloroform–methanol, 2:1:0.5). – IR (KBr): 3355 (NH), 3246 (NH), 1705 (C=O), 1669 (C=O), 1593 (C=N) cm−1. – 1H NMR (CDCl3): δ = 2.25 (s, 3H, CH3), 3.85 (s, 2H, CH2), 6.22–6.24 (m, 2H, Ar-H), 6.36 (s, 1H, Ar-H), 6.65–6.67 (d, J = 7.5 Hz, 2H), 6.88–6.90 (m, 1H, Ar-H), 7.07–7.08 (d, J = 2.0 Hz, 2H), 7.15–7.18 (m, 3H, Ar-H), 7.67–7.69 (d, J = 2.0 Hz, 1H), 8.22–8.23 (m, 1H, Ar-H), 8.45 (br s, 1H, NH), 8.67 (br s, 1H, NH). – 13C NMR (CDCl3): δ = 13.85, 56.85, 112.89, 116.84, 118.89, 120.81, 126.35, 126.81, 126.95, 127.73, 128.72, 128.89, 130.78, 131.16, 134.55, 145.89, 153.68, 155.92, 159.75; 162.79, 168.95. – MS (EI, 70 eV): m/z (%) = 385 (M+). – C23H20N4O2: calcd. C 71.86, H 5.24, N 14.57; found C 71.89, H 5.34, N 14.39.

4.15 Pharmacology

The synthesized compounds were evaluated for analgesic and anti-inflammatory activities. A Student’s t-test was performed to ascertain the significance of all the exhibited activities. The test compounds and the standard drugs were administered in the form of a suspension (1 % carboxy methyl cellulose as a vehicle) by oral route. Each group consisted of six animals. The animals were maintained in colony cages at 25 ± 2 °C, relative humidity of 45 %–55 %, under a 12 h light and dark cycle; they were fed standard animal feed. All the animals were acclimatized for a week before use. The experimental protocol was duly approved by the Institutional Animal Ethical Committee (IAEC, F. No.25/559/2010-AWD) constituted by Committee for the Purpose of Control and Supervision of Experimental Animals (CPCSEA), Ministry of Environment and Forest, New Delhi, India (IAEC, F. No.25/559/2010-AWD).

4.16 Analgesic activity

The analgesic activity was performed by the tail-flick technique [15, 16] using Wistar albino mice (25–35 g) of either sex selected by the random sampling technique. Diclofenac sodium at a dose level of 10 mg kg−1 was administered orally as a reference drug for comparison. The test compounds at a dose level of 10 mg kg−1 were administered orally. The reaction time was recorded at 30 min, 1, 2, and 3 h after the treatment, and cut-off time was 10 s. The percent analgesic activity (PAA) was calculated by the following formula:

PAA = [T2 − T110 − T1] × 100

where T1 is the reaction time (s) before treatment, and T2 is the reaction time (s) after treatment.

4.17 Anti-inflammatory activity

Anti-inflammatory activity was evaluated by the carrageenan-induced paw edema test in rats [17]. Diclofenac sodium 10 mg kg−1 was administered as a standard drug for comparison. The test compounds were administered at a dose of 10 mg kg−1. The paw volumes were measured using the mercury displacement technique with the help of a plethysmograph (Inlab, Chennai, India) immediately before and 30 min, 1, 2, and 3 h after carrageenan injection. The percent inhibition of paw edema was calculated using the following formula:

Percent inhibition I = 100[1 − (a − x)/(b − y)]

where x is the mean paw volume of rats before the administration of carrageenan and test compounds or reference compound (test group), a is the mean paw volume of rats after the administration of carrageenan in the test group (drug treated), b is the mean paw volume of rats after the administration of carrageenan in the control group, and y is the mean paw volume of rats before the administration of carrageenan in the control group.

4.18 Evaluation of ulcerogenicity index

Ulceration in rats was induced as described by Goel et al. [18]. Albino rats of Wistar strain weighing 150–200 g of either sex were divided into various groups each of six animals. The control groups of animals were administered only with 10 % v/v Tween 80 suspension intraperitonially. One group was administered with aspirin (ASA) (German Remedies, Mumbai, India) intraperitoneally at a dose of 20 mg kg−1 once daily for 3 days. The remaining group of animals was administered with test compounds intraperitoneally at a dose of 20 mg kg−1. The fourth day, pylorus was ligated by the method of Shay et al. [19]. Animals were fasted for 36 h before the pylorus ligation procedure. Four hours after the ligation, animals were killed. The stomach was removed and opened along with the greater curvature. Ulcer index was determined by the method of Ganguly and Bhatnagar [20] and is recorded in Table 3.

Table 3

Evaluation of ulcerogenicity index.

CompoundUlcer indexa
V30.53 ± 1.32b
V40.55 ± 1.53b
V90.51 ± 1.62b
Control0.15 ± 0.32
Diclofenac1.65 ± 0.59c
Aspirin1.73 ± 0.41c

aData expressed as mean ± SD from six different experiments done in duplicate; significance levels bp < 0.05 and cp < 0.01 as compared to the respective control.

4.19 Statistical analysis

Statistical analysis of the biological activity of the synthesized compounds on animals was evaluated using a one-way analysis of variance (ANOVA). In all cases, post-hoc comparisons of the means of individual groups were performed using Tukey’s test. A level of p < 0.05 denoted significance in all cases. All values are expressed as mean ± SD. For statistical analysis we have used GraphPad Prism, version 3.0 (GraphPad Software, Inc., San Diego, CA, USA).

Corresponding author: Veerachamy Alagarsamy, Medicinal Chemistry Research Laboratory, MNR College of Pharmacy, MNR Nagar, Sangareddy-502 294, Telangana, India, Tel.: +91-8455-230690, Fax: +91-8455-230555, E-mail:

References

[1] J. R. Vane, R. M. Botting, Inflamm. Res.1995, 44, 1.10.1007/BF01630479Search in Google Scholar

[2] J. van Ryn, G. Trummlitz, M. Pairet, Curr. Med. Chem.2000, 7, 1145.10.2174/0929867003374255Search in Google Scholar

[3] J. R. Vane, Nature New Biol.1971, 231, 232.10.1038/newbio231232a0Search in Google Scholar

[4] M. Beuck, Angew. Chem. Int. Ed.1999, 38, 631.10.1002/(SICI)1521-3773(19990301)38:5<631::AID-ANIE631>3.0.CO;2-SSearch in Google Scholar

[5] V. Alagarsamy, V. R. Solomon, S. Murugesan, Arzneimittelforschung (Drug. Res.)2008, 58, 174.Search in Google Scholar

[6] V. Alagarsamy, D. Shankar, V. R. Solomon, R. V. Sheorey, P. Parthiban, Acta Pharm.2009, 59, 75.10.2478/v10007-009-0004-0Search in Google Scholar

[7] V. Alagarsamy, S. Meena, K. V. Ramaseshu, V. R. Solomon, T. D. Kumar, K. Thirumurugan, Chem. Biol. Drug Des.2007, 70, 254.10.1111/j.1747-0285.2007.00548.xSearch in Google Scholar

[8] G. Saravanan, V. Alagarsamy, C. R. Prakash, Bioorg. Med. Chem. Lett.2012, 22, 3072.10.1007/s00044-012-0037-7Search in Google Scholar

[9] M. Banerjee, C. C. Behera, G. C. Pradhan, M. A. Azam, S. K. Sahu, S. Afr. J. Chem.2009, 62, 134.Search in Google Scholar

[10] A. E. Abdel-Rahman, E. A. Bakhite, E. A. Al-Taifi, Pharmazie2000, 58, 372.Search in Google Scholar

[11] A. S. El-Azab, K. E. ElTahir, Bioorg. Med. Chem. Lett.2012, 22, 327.10.1016/j.bmcl.2012.01.071Search in Google Scholar

[12] V. Alagarsamy, V. Muthukumar, N. Pavalarani, P. Vasanthanathan, R. Revathi, Biol. Pharm. Bull.2003, 26, 557.10.1248/bpb.26.557Search in Google Scholar

[13] V. Alagarsamy, V. R. Salomon, G. Vanikavitha, V. Paluchamy, M. R. Chandran, A. A. Sujin, A. Thangathiruppathy, S. Amuthalakshmi, R. Revathi, Biol. Pharm. Bull.2002, 25, 1432.10.1248/bpb.25.1432Search in Google Scholar

[14] V. Alagarsamy, V. Raja Solomon, M. Murugan, K. Dhanabal, P. Parthiban, G. V. Anjana, J. Enzyme Inhib. Med. Chem.2008, 23, 839.10.1080/14756360701746229Search in Google Scholar

[15] S. K. Kulkarni, Life Sciences1980, 27, 185.10.1016/0024-3205(80)90136-8Search in Google Scholar

[16] F. E. D’Amour, D. L. Smith, J. Pharmacol. Exp. Therap.1941, 72, 74.Search in Google Scholar

[17] C. A. Winter, E. A. Risely, G. W. Nuss, Exp. Biol. Med.1962, 111, 544.10.3181/00379727-111-27849Search in Google Scholar

[18] R. K. Goel, A. Chakrabarti, A. K. Sanyal, Planta Med.1985, 51, 85.10.1055/s-2007-969412Search in Google Scholar

[19] M. Shay, S. A. Komarov, S. S. Fels, D. Meranze, H. Gruenstein, H. Siplet, Gastroenterology1945, 5, 43.Search in Google Scholar

[20] A. K. Ganguly, O. P. Bhatnagar, Can. J. Physiol. Pharmacol.1973, 51, 748.10.1139/y73-113Search in Google Scholar

Received: 2015-2-17
Accepted: 2015-4-2
Published Online: 2015-6-23
Published in Print: 2015-8-1

©2015 by De Gruyter

Articles in the same Issue

  1. Frontmatter
  2. In this Issue
  3. Synthesis, crystal structure and magnetic characterization of a cyanide-bridged Mo–Ni nanosized molecular wheel
  4. A novel γ-lactone derivative from the twigs of Turraea pubescens
  5. A cyclic mixed-valence MoVI/MoV polyoxothiomolybdate cluster anion stabilized by a [(μ-I){Ag(PPh3)3}2]+ complex cation. Preparation and structure of [(μ-I){Ag(PPh3)3}2]2 [Mo8O8(μ-OH)2(μ-OEt)6(μ-S)8(μ3-O)4{Mo(DMF)2}] · 2EtOH
  6. Synthesis and characterization of silver(I) complexes of thioureas and thiocyanate: crystal structure of polymeric (1,3-diazinane-2-thione)thiocyanato silver(I)
  7. A molecular crown analogue templated by Keggin polyanions: synthesis, structure, and electrochemical and luminescent properties
  8. 1-(2′-Benzimidazolylmethyl)-pyridinium ylide in the one-pot synthesis of indolizine and benzimidazo[1,2-a]pyridine derivatives
  9. Orthoamide und Iminiumsalze, XC. Das RIBIL-Konzept – Reaktive Iminiumsalz-basierte ionische Flüssigkeiten
  10. Cyclophanes, Part 73: diastereoselective dimerization of an α,β-unsaturated ketone. Structure of all-trans-1,3-dibenzoyl-2,4-di([2.2]paracyclophan-4-yl)cyclobutane
  11. Crystal structures and luminescence properties of two Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-6-methyl-1H-benzimidazole
  12. Tetrahedral boronates as basic catalysts in the aldol reaction
  13. Design and synthesis of quinazolinyl acetamides for their analgesic and anti-inflammatory activities
  14. Crystal structure and photoluminescence of a new two-dimensional Cd(II) coordination polymer based on 3-(carboxymethoxy)-2-naphthoic acid
  15. Synthesis, anti-HIV activity and molecular modeling study of 3-aryl-6-adamantylmethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives
https://doi.org/10.1515/znb-2015-0035
Keywords for this article
analgesic; anti-inflammatory; quinazoline; ulcer index

Articles in the same Issue

  1. Frontmatter
  2. In this Issue
  3. Synthesis, crystal structure and magnetic characterization of a cyanide-bridged Mo–Ni nanosized molecular wheel
  4. A novel γ-lactone derivative from the twigs of Turraea pubescens
  5. A cyclic mixed-valence MoVI/MoV polyoxothiomolybdate cluster anion stabilized by a [(μ-I){Ag(PPh3)3}2]+ complex cation. Preparation and structure of [(μ-I){Ag(PPh3)3}2]2 [Mo8O8(μ-OH)2(μ-OEt)6(μ-S)8(μ3-O)4{Mo(DMF)2}] · 2EtOH
  6. Synthesis and characterization of silver(I) complexes of thioureas and thiocyanate: crystal structure of polymeric (1,3-diazinane-2-thione)thiocyanato silver(I)
  7. A molecular crown analogue templated by Keggin polyanions: synthesis, structure, and electrochemical and luminescent properties
  8. 1-(2′-Benzimidazolylmethyl)-pyridinium ylide in the one-pot synthesis of indolizine and benzimidazo[1,2-a]pyridine derivatives
  9. Orthoamide und Iminiumsalze, XC. Das RIBIL-Konzept – Reaktive Iminiumsalz-basierte ionische Flüssigkeiten
  10. Cyclophanes, Part 73: diastereoselective dimerization of an α,β-unsaturated ketone. Structure of all-trans-1,3-dibenzoyl-2,4-di([2.2]paracyclophan-4-yl)cyclobutane
  11. Crystal structures and luminescence properties of two Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-6-methyl-1H-benzimidazole
  12. Tetrahedral boronates as basic catalysts in the aldol reaction
  13. Design and synthesis of quinazolinyl acetamides for their analgesic and anti-inflammatory activities
  14. Crystal structure and photoluminescence of a new two-dimensional Cd(II) coordination polymer based on 3-(carboxymethoxy)-2-naphthoic acid
  15. Synthesis, anti-HIV activity and molecular modeling study of 3-aryl-6-adamantylmethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 11.10.2025 from https://www.degruyterbrill.com/document/doi/10.1515/znb-2015-0035/html?srsltid=AfmBOor5Wc8oDM4Na8POFVSuZH6gCZkH8hrMziTNOAJ-7FSI98CJ06eW
Scroll to top button