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Simple access to spirooxadiazole compounds containing a quinoxaline moiety using a nitrile imine intermediate generated in situ

  • Abdolali Alizadeh EMAIL logo and Leila Moafi
Published/Copyright: September 15, 2017
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Heterocyclic Communications
From the journal Heterocyclic Communications Volume 23 Issue 5

Abstract

A convenient method for the synthesis of spiro[indeno[1,2-b]quinoxaline-[1,3,4]oxadiazole]s involves a 1,3-dipolar cycloaddition reaction of nitrile imines generated in situ with indenoquinoxaline derivatives.

Keywords: 1,3-dipolar cycloaddition; nitrile imine; nitrogen containing heterocycles; quinoxaline

Introduction

Quinoxaline and its derivatives play a significant role in organic synthesis [1]. Many quinoxalines are antimicrobial [2], anti-hypertensive [3], anti-tubercular [4], anti-depressant [5], anti-malarial [6], anti-inflammatory [7], anti-convulsant [8], anti-HIV [9], anti-diabetic and anticancer agents [10, 11]. They are also used in the synthesis of organic semiconductors [12], rigid subunits of macrocyclic receptors for molecular recognition [13] and chemically controllable switches [14].

Spirocyclic molecules are of considerable interest as natural and synthetic products including optoelectronic materials [15]. Spiro frameworks are found in phytochemicals such as alkaloids, lactones and terpenoids [16]. 1,3-Dipolar cycloaddition is a powerful route for the synthesis of five-membered spiro compounds [17, 18]. Nitrile imines are important 1,3-dipoles [19] that are easily generated in situ by the treatment of hydrazonoyl chlorides with Et3N. The reaction of these dipoles with a carbonyl group constitutes an efficient method for the regio- and stereoselective synthesis of structurally complex spirooxadiazole heterocycles from readily available precursors. Although the reactions of 1,3-dipoles with olefinic substrates have been studied extensively [20, 21], methods for the synthesis of oxadiazoles using the reaction of 1,3-dipoles and carbonyl units are rare [22]. In continuation of our efforts on the synthesis of heterocyclic compounds using nitrile imines [23], we describe an efficient procedure for the synthesis of spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole] derivatives 3 by the reaction of ninhydrin, phenylenediamines 1 and hydrazonoyl chlorides 2 in the presence of Et3N in EtOH at room temperature.

Results and discussion

A mixture of phenylenediamine 1a (Table 1) and ninhydrin was stirred in ethanol under reflux conditions for 1 h followed by the addition of hydrazonoyl chloride 2a (Ar=Ph) and Et3N. After an additional stirring at room temperature for 2 h, the product 3a was obtained in an 80% yield. Other products 3b,c were obtained in high yields in a similar way. The structural determination of 3a–c was achieved by analysis of 1H NMR, 13C NMR and IR spectroscopic data. The mass spectra of all products display a molecular ion peak and their 1H NMR spectra are fully consistent with the assigned structures. A characteristic peak for a spiro carbon at 99.6–99.9 ppm appears in the 13C NMR spectra of compounds 3a–c. Additional compounds 3d–f synthesized using methyl-substituted 1,2-benzenediamines are listed in Table 2. As expected, mixtures of two isomers were obtained in each case because the starting diamines contained two nonequivalent amino groups. A proposed mechanism for this reaction is exemplified in Scheme 1 by the synthesis of product 3a. Initially, a quinoxaline 4a is formed by the reaction of phenylenediamine 1a and ninhydrin. In a parallel reaction, an intermediate nitrile imine A is generated from hydrazonoyl chloride 2a. A 1,3-dipolar cycloaddition reaction of intermediate products A and 4a leads to the formation of the final product 3a.

Table 1

Synthesis of spiro[indeno[1,2-b]quinoxaline-[1,3,4]oxadiazole]s 3a–c using 1a.

EntryAr
3aPh
3bp-Cl-Ph
3cp-OMe-Ph
Table 2

Synthesis of compound 3d–f.

EntryR1R2Ar
3dMeHPh
3eMeHp-Cl-Ph
3fHMePh
Scheme 1 Proposed mechanism for the synthesis of compounds 3a–f using 3a as an example.
Scheme 1

Proposed mechanism for the synthesis of compounds 3a–f using 3a as an example.

Conclusion

A facile synthetic route to spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole]s starting with readily available starting materials was developed.

Experimental

1H-NMR (300 MHz) and 13C-NMR (75 MHz) spectra were obtained using a Bruker DRX-300 AVANCE spectrometer in CDCl3 as solvent. IR spectra were recorded on a NICOLET FT-IR 100 spectrophotometer. Electron-impact mass spectra were recorded on a FINNIGAN-MATT 8430 instrument operating at an ionization potential of 70 eV. Melting points were determined with an Electrothermal 9100 apparatus. Hydrazonoyl chlorides 2 were obtained as previously reported [24, 25].

General procedure for the synthesis of 3a–f

A mixture of phenylenediamine 1 (1 mmol) and ninhydrin (1 mmol) in EtOH (4 mL) was stirred under reflux for 1 h. Then, hydrazonoyl chloride 2 (1 mmol) and Et3N (1 mmol) were added and the mixture was stirred at room temperature for an additional period indicated below. Progress of the reaction was monitored by TLC analysis. After completion of the reaction, the resultant precipitate was washed with acetone to afford the pure product 3a–f.

3′,5′-Diphenyl-3′H-spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole] (3a)

Reaction time 3 h; yield of a yellow powder 80%; mp 232–234°C; 1H NMR: δ 8.38 (d, 1H, J=4.8 Hz), 8.26 (d, 1H, J=6.9 Hz), 8.11 (d, 1H, J=8.1 Hz), 7.94 (d, 2H, J=6.4 Hz), 7.71–7.80 (m, 4H), 7.60 (t, 1H, J=6.9 Hz), 7.42–7.46 (m, 3H), 6.98 (t, 2H, J=7.2 Hz), 6.74–6.76 (m, 3H); 13C NMR: δ 157.2, 152.8, 151.9, 143.2, 142.3, 142.1, 141.6, 136.2, 133.4, 132.5, 131.6, 131.5, 130.4, 130.0, 128.9, 128.6, 128.3, 126.5, 126.1, 125.3, 123.7, 120.7, 114.7, 99.6; EI-MS: m/z 426 [M+], 306, 106, 91 and 77. Anal. Calcd for C28H18N4O (426.48): C, 78.86; H, 4.25; N, 13.14. Found: C, 78.92; H, 4.29; N, 13.20.

5′-(4-Chlorophenyl)-3′-phenyl-3′H-spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole] (3b)

Reaction time 5 h; 78% yield of a yellow powder; mp 228–230°C; 1H NMR: δ 8.24 (d, 1H, J=6.1 Hz), 8.15 (d, 1H, J=7.2 Hz), 8.08 (d, 1H, J=6.9 Hz), 7.86 (d, 2H, J=6.4 Hz), 7.67–7.77 (m, 4H), 7.55 (t, 1H, J=6.1 Hz), 7.41 (d, 2H, J=6.4 Hz), 6.97 (t, 2H, J=7.2 Hz), 6.74–6.76 (m, 3H); 13C NMR: δ 156.7, 153.1, 152.0, 143.6, 142.7, 142.3, 142.1, 137.7, 136.5, 132.9, 132.5, 131.1, 130.5, 129.7, 129.4, 129.1, 129.0, 127.9, 126.2, 124.1, 122.8, 120.9, 114.7, 99.9. Anal. Calcd for C28H17ClN4O (460.92): C, 72.96; H, 3.72; N, 12.16. Found: C, 72.91; H, 3.80; N, 12.13.

5′-(4-Methoxyphenyl)-3′-phenyl-3′H-spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole] (3c)

Reaction time 6 h; 86% yield of a pink powder; mp 232–234°C; 1H NMR: δ 8.22 (d, 1H, J=7.5 Hz), 8.14 (d, 1H, J=8.2 Hz), 8.09 (d, 1H, J=8.3 Hz), 7.87 (d, 2H, J=8.5 Hz), 7.62–7.78 (m, 4H), 7.53 (t, 1H, J=7.5 Hz), 6.93–6.96 (m, 4H), 6.73 (d, 2H, J=8.5 Hz), 6.66 (t, 1H, J=7.0 Hz), 3.85 (s, 3H); 13C NMR: δ 161.6, 157.1, 153.2, 152.9, 143.6, 143.1, 142.6, 142.3, 137.4, 132.9, 132.3, 130.9, 130.5, 129.6, 129.4, 129.0, 128.9, 128.4, 126.2, 122.7, 120.5, 118.1, 114.7, 114.1, 99.6, 55.5. Anal. Calcd for C29H20N4O2 (456.50): C, 76.30; H, 4.42; N, 12.27. Found: C, 76.23; H, 4.36; N, 12.21.

Mixture of 7-methyl-3′,5′-diphenyl-3′H-spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole] and its 8-methyl-regioisomer (3d)

Reaction time 3 h; 80% yield of an orange powder; mp 221–223°C; 1H NMR: δ 8.22 (d, 2H, J=7.2 Hz), 7.93–8.05 (m, 6H), 7.87 (s, 2H), 7.43–7.72 (m, 14H), 6.96 (t, 4H, J=7.6 Hz), 6.75 (d, 4H, J=7.8 Hz), 6.68 (t, 2H, J=7.1 Hz), 2.59 (s, 3H, Me of minor isomer), 2.52 (s, 3H, Me of major isomer); 13C NMR of major isomer: δ 156.8; 155.9, 152.4, 143.6, 142.9, 142.3, 140.4, 137.6, 133.2, 132.8, 132.3, 130.5, 130.0, 129.6, 129.0, 128.8, 128.7, 126.6, 126.1, 125.6, 122.7, 120.6, 114.7, 99.86, 22.0; 13C NMR of minor isomer: δ 156.8, 153.2, 152.4, 143.6, 142.7, 141.8, 140.7, 137.6, 133.2, 132.6, 131.9, 130.5, 130.0, 129.6, 129.0, 128.7, 128.5, 126.6, 126.1, 125.6, 122.6, 120.6, 114.7, 99.81, 21.8. Anal. Calcd for C29H20N4O (440.50): C, 79.07; H, 4.58; N, 12.72. Found: C, 71.11; H, 4.50; N, 12.77.

Mixture of 5′-(4-chlorophenyl)-7-methyl-3′-phenyl-3′H-spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole] and its 8-methyl-regioisomer (3e)

Reaction time 5 h; 78% yield of an orange powder; mp 240–242°C; 1H NMR: δ 8.16–8.19 (m, 4H), 7.93–7.96 (m, 4H), 7.90 (s, 1H), 7.88 (s, 1H), 7.79–7.82 (m, 4H), 7.65–7.69 (m, 4H), 7.45 (d, 4H, J=8.1 Hz), 7.20 (t, 4H, J=7.3 Hz), 6.89–6.93 (m, 6H), 2.65 (s, 3H, Me of major isomer), 2.62 (s, 3H, Me of minor isomer); 13C NMR of major isomer: δ 166.6; 155.1, 154.7, 149.4, 148.6, 147.5, 144.9, 137.6, 136.2, 133.9, 133.8, 132.5, 131.9, 131.3, 130.5, 130.0, 129.2, 128.6, 125.5, 124.1, 122.4, 121.1, 114.6, 99.9, 21.67; 13C NMR of minor isomer: δ 166.6, 155.1, 154.7, 149.4, 148.6, 147.5, 144.9, 137.6, 136.2, 133.9, 133.8, 132.5, 131.9, 131.3, 130.5, 130.0, 129.8, 128.8, 125.6, 124.2, 123.3, 121.1, 113.3, 99.9, 21.68. Anal. Calcd for C29H19ClN4O (474.94): C, 73.34; H, 4.03; N, 11.80. Found: C, 73.29; H, 4.08; N, 11.71.

Mixture of 6-methyl-3′,5′-diphenyl-3′H-spiro[indeno[1,2-b]quinoxaline-11,2′-[1,3,4]oxadiazole] and its 9-methyl-regioisomer (3f)

Reaction time 5 h; 75% yield of an orange powder; mp 227–229°C; 1H NMR: δ 8.21–8.23 (3H, m), 7.92–7.94 (6H, m), 7.43–7.58 (15H, m), 6.94–6.97 (5H, m), 6.74–6.76 (5H, m), 2.89 (3H, s, Me of minor isomer), 2.87 (3H, s, Me of major isomer); 13C NMR of major isomer: δC 156.1, 153.5, 152.7, 142.7, 142.4, 142.3, 142.2, 137.7, 136.6, 132.5, 132.2, 131.3, 130.5, 129.3, 128.9, 128.6, 128.5, 128.3, 126.6, 124.0, 122.7, 120.4, 114.1, 99.7, 17.39; 13C NMR of minor isomer: δC 156.1, 153.5, 152.5, 142.7, 142.5, 142.3, 142.1, 137.7, 136.6, 132.7, 132.2, 131.3, 130.6, 129.4, 128.9, 128.7, 128.6, 128.3, 126.4, 124.0, 122.5, 120.5, 114.3, 99.8, 17.40. Anal. Calcd for C29H20N4O (440.50): C, 79.07; H, 4.58; N, 12.72. Found: C, 79.15; H, 4.63; N, 12.65.

Acknowledgments

Financial support for this research from Tarbiat Modares University, Iran, is gratefully acknowledged.

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Received: 2017-5-2
Accepted: 2017-7-21
Published Online: 2017-9-15
Published in Print: 2017-10-26

©2017 Walter de Gruyter GmbH, Berlin/Boston

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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  2. Review
  3. Chemical constituents from the genus Saussurea and their biological activities
  4. Preliminary Communication
  5. A new imidazoline-containing Bunte salt: synthesis, molecular and electronic structure
  6. Research Articles
  7. One-pot synthesis of 1-substituted 1H-1,2,3,4-tetrazoles from 2aminothiazoles using tributylmethylammonium chloride as a catalyst
  8. A new method for the synthesis of 4H-1,3,5-oxadiazine derivatives
  9. Simple access to spirooxadiazole compounds containing a quinoxaline moiety using a nitrile imine intermediate generated in situ
  10. A convenient regioselective synthesis of spirooxindolinopyrrolizidines incorporating the pyrene moiety through a [3 + 2]-cycloaddition reaction
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  12. A selective fluorescence probe based on benzothiazole for the detection of Cr3+
  13. Spectrophotometric and quantum-chemical study of acid-base and complexing properties of (±)-taxifolin in aqueous solution
  14. Preparation of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones using ZrO2 nanoparticles as a catalyst under solvent-free conditions
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https://doi.org/10.1515/hc-2017-0084
Keywords for this article
1,3-dipolar cycloaddition; nitrile imine; nitrogen containing heterocycles; quinoxaline
Creative Commons
BY-NC-ND 3.0

Articles in the same Issue

  1. Frontmatter
  2. Review
  3. Chemical constituents from the genus Saussurea and their biological activities
  4. Preliminary Communication
  5. A new imidazoline-containing Bunte salt: synthesis, molecular and electronic structure
  6. Research Articles
  7. One-pot synthesis of 1-substituted 1H-1,2,3,4-tetrazoles from 2aminothiazoles using tributylmethylammonium chloride as a catalyst
  8. A new method for the synthesis of 4H-1,3,5-oxadiazine derivatives
  9. Simple access to spirooxadiazole compounds containing a quinoxaline moiety using a nitrile imine intermediate generated in situ
  10. A convenient regioselective synthesis of spirooxindolinopyrrolizidines incorporating the pyrene moiety through a [3 + 2]-cycloaddition reaction
  11. An efficient green synthesis of 5H-spiro[benzo[4,5]imidazo[1,2-c]quinazoline-6,3′-indolin]-2′-ones catalyzed by iodine in ionic liquids
  12. A selective fluorescence probe based on benzothiazole for the detection of Cr3+
  13. Spectrophotometric and quantum-chemical study of acid-base and complexing properties of (±)-taxifolin in aqueous solution
  14. Preparation of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones using ZrO2 nanoparticles as a catalyst under solvent-free conditions
  15. Microwave-assisted synthesis of bis(N-substituted thiazol-2-amine) derivatives and their biological activities
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