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One-pot synthesis of 4-alkyl-2-amino-4H-chromene derivatives

  • Ivan N. Bardasov EMAIL logo , Anastasiya U. Alekseeva , Oleg V. Ershov and Dmitry A. Grishanov
Published/Copyright: June 2, 2015
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Heterocyclic Communications
From the journal Heterocyclic Communications Volume 21 Issue 3

Abstract

A one-pot synthesis of 4-alkyl-2-amino-4H-chromene derivatives by base-initiated reactions of aliphatic aldehydes, malononitrile, and resorcinol in water is described.

Keywords: cyano compounds; heterocycles; Knoevenagel condensation; Michael addition; pyrans

Introduction

2-Amino-4H-pyrans are attractive molecules because of their diverse biological activity, which includes antibacterial [1–5], fungicidal [6], molluscicidal [7–8], and anticancer [9–14] properties. Among them, 4-aryl-4H-chromenes receive special attention as potent apoptosis inducing agents possessing vascular targeting activity [10, 11]. These compounds are tubulin inhibitors, binding at or close to the binding site of colchicine, possessing vascular targeting activity and showing high activity in several anticancer animal models [11]. In contrast to the preparation of the 4-aryl derivatives, the synthesis of 4-alkyl-4H-chromenes is poorly represented in the literature.

Results and discussion

In earlier published works, there are two approaches to the synthesis of 4-alkyl-2-amino-4H-chromenes. The first involves the reaction of 2-(2-acyl- or 2-nitrovinyl)phenols and malononitrile that leads to the 4-acyl- or 4-nitromethyl-2-amino-4H-chromenes [15–17]. The second variant is based on the base-initiated reaction between 3,4-unsubstituted coumarins and malononitrile followed by ring-opening and ring-closing reactions [13, 14, 18]. However, these methods are not suitable for the synthesis of simple 4-alkyl-2-amino-4H-chromenes.

A common method for the synthesis of 2-amino-4-aryl-4H-chromene-3-carbonitriles and similar compounds is the three-component condensation of malononitrile, aromatic aldehyde, and phenol or cyclic 1,3-dicarbonyl compound in various solvents [11, 19, 20]. Using this approach to obtain new derivatives of 2-amino-4H-chromenes, we investigated the reaction of aliphatic aldehydes 1, malononitrile and resorcinol, that gave 4-alkyl-2-amino-7-hydroxy-4H-chromene-3-carbonitriles 2a–h in 23–76% yields (Scheme 1).

Scheme 1 One-pot synthesis of 4-alkyl-2-amino-4H-chromene derivatives 2a–h.
Scheme 1

One-pot synthesis of 4-alkyl-2-amino-4H-chromene derivatives 2a–h.

Low yields of compounds 2a,b are apparently due to the resorcinol-aldehyde condensations. The structures of compounds 2a–h were confirmed by IR, NMR spectroscopy, and mass spectrometry.

Conclusions

In this paper, we described the eco-friendly synthesis of 4-alkyl-2-amino-4H-chromene derivatives using the methodology of a multicomponent synthesis. There are several articles that describe the synthesis of 4-alkyl-2-amino-4H-chromene derivatives 2c,h using ultrasound irradiation and Fe3O4 or MgO nanoparticles as catalyst [21–24]. However, their NMR data (13C NMR data in particular) and melting points are different from ours and incorrect. Accordingly, this article describes the method of synthesis of 4-alkyl-2-amino-4H-chromene derivatives for the first time.

Experimental

The reaction progress was monitored and the purity of compounds was analyzed by TLC on Silufol UV-254 plates (development by UV irradiation, exposure to iodine vapor, or thermal decomposition). IR spectra were recorded on an IR Fourier spectrophotometer FSM-1202 using mulls in mineral oil. The 1H and 13C NMR spectra were registered on a spectrometer Bruker DRX-500 (500 and 125 MHz, respectively) in DMSO-d6. Mass spectra were taken on a Finnigan MAT INCOS-50 instrument (EI, 70 eV).

General procedure for the synthesis of 4-alkyl-2-amino-7-hydroxy-4H-chromene-3-carbonitriles 2

A solution of resorcinol (10 mmol) and KOH (10 mmol) in water (10 mL) was added to a mixture of aliphatic aldehyde 1 (10 mmol) and malononitrile (10 mmol) in water (10 mL). The mixture was stirred at room temperature for 60 min. The resulting precipitate was filtered, washed with water, dried, and crystallized from benzene or mixture of benzene and isopropanol.

2-Amino-7-hydroxy-4H-chromene-3-carbonitrile (2a)

This compound was obtained in 23% yield (0.43 g) as a pale yellow solid; mp 198–199°C (dec); 1H NMR: δ 3.32 (s, 2H, CH2), 6.34 (d, 1H, J = 2.4 Hz, CH), 6.52 (dd, 1H, J = 8.3 Hz, J = 2.4 Hz, CH), 6.70 (s, 2H, NH2), 6.96 (d, 1H, J = 8.3 Hz, CH), 9.60 (s, 1H, OH). IR: 3413, 3325, 3221 (NH2, OH), 2179 (CN), 1632 cm-1 (C=C); MS: m/z (%) 188 [M]+ (56), 187 [M–1]+ (100). Anal. Calcd for C10H8N2O2: C, 63.83; H, 4.29; N, 14.89. Found: C, 63.69; H, 4.42; N, 14.73.

2-Amino-7-hydroxy-4-methyl-4H-chromene-3-carbonitrile (2b)

This compound was obtained in 38% yield (0.77 g) as a white solid; mp 159–160°C (dec); 1H NMR: δ 1.25 (d, 3H, J = 6.7 Hz, CH3), 3.46 (q, 1H, J = 6.7 Hz, CH), 6.33 (d, 1H, J = 2.4 Hz, CH), 6.55 (dd, 1H, J = 8.4 Hz, J = 2.4 Hz, CH), 6.65 (s, 2H, NH2), 7.06 (d, 1H, J = 8.4 Hz, CH), 9.59 (s, 1H, OH); IR: 3436, 3328, 3210 (NH2, OH), 2180 (CN), 1637 cm–1 (C=C); MS: m/z (%) 202 [M]+ (5), 187 [M–15]+ (100). Anal. Calcd for C11H10N2O2: C, 65.34; H, 4.98; N, 13.85. Found: C, 65.53; H, 4.89; N, 13.86.

2-Amino-7-hydroxy-4-propyl-4H-chromene-3-carbonitrile (2c)

This compound was obtained in 65% yield (1.49 g) as a white solid; mp 145–146°C (mp 160–162°C [24]); 1H NMR: δ 0.82 (t, 3H, J = 7.3 Hz, CH3), 1.01–1.09 (m, 1H, CH2), 1.20–1.27 (m, 1H, CH2), 1.47–1.59 (m, 2H, CH2), 3.44 (t, 1H, J = 5.0 Hz, CH), 6.34 (d, 1H, J = 2.4 Hz, CH), 6.55 (dd, 1H, J = 8.4 Hz, J = 2.4 Hz, CH), 6.69 (s, 2H, NH2), 7.01 (d, 1H, J = 8.4 Hz, CH), 9.59 (s, 1H, OH); 13C NMR: δ 161.2, 156.8, 149.9, 128.7, 121.1, 114.1, 112.0, 102.2, 54.5, 40.4, 33.7, 17.5, 14.0; IR: 3434, 3340, 3217 (NH2, OH), 2178 (CN), 1647 cm-1 (C=C); MS: m/z (%) 230 [M]+ (5), 187 [M–43]+ (100). Anal. Calcd for C13H14N2O2: C, 67.81; H, 6.13; N, 12.17. Found: C, 67.59; H, 6.23; N, 12.28.

2-Amino-7-hydroxy-4-isopropyl-4H-chromene-3-carbonitrile (2d)

This compound was obtained in 72% yield (1.66 g) as a white solid; mp 196–198°C; 1H NMR: δ 0.70 (d, 3H, J = 6.8 Hz, CH3), 0.82 (d, 3H, J = 6.8 Hz, CH3), 1.77 (d sept, 1H, J = 6.8 Hz, J = 3.6 Hz, CH), 3.25 (d, 1H, J = 3.5 Hz, CH), 6.36 (d, 1H, J = 2.4 Hz, CH), 6.55 (dd, 1H, J = 8.4 Hz, J = 2.4 Hz, CH), 6.74 (s, 2H, NH2), 6.97 (d, 1H, J = 8.4 Hz, CH), 9.58 (s, 1H, OH). IR: 3439, 3345, 3218 (NH2, OH), 2178 (CN), 1639 cm–1 (C=C); MS: m/z (%) 230 [M]+ (2), 187 [M–43]+ (100). Anal. Calcd for C13H14N2O2: C, 67.81; H, 6.13; N, 12.17. Found: C, 67.75; H, 6.18; N, 12.21.

2-Amino-7-hydroxy-4-pentyl-4H-chromene-3-carbonitrile (2e)

This compound was obtained in 75% yield (1.94 g) as a white solid; mp 132–133°C; 1H NMR: δ 0.80 (t, 3H, J = 6.9 Hz, CH3), 1.01–1.60 (m, 8H, (CH2)4), 3.45 (t, 1H, J = 4.8 Hz, CH), 6.33 (d, 1H, J = 2.1 Hz, CH), 6.54 (dd, 1H, J = 8.4 Hz, J = 2.1 Hz, CH), 6.68 (s, 2H, NH2), 7.01 (d, 1H, J = 8.4 Hz, CH), 9.59 (s, 1H, OH). IR: 3420, 3339, 3220 (NH2, OH), 2174 (CN), 1646 cm-1 (C=C); MS: m/z (%) 258 [M]+ (3), 187 [M–71]+ (100). Anal. Calcd for C15H18N2O2: C, 69.74; H, 7.02; N, 10.84. Found: C, 69.82; H, 6.97; N, 10.73.

2-Amino-7-hydroxy-4-(pentan-3-yl)-4H-chromene-3-carbonitrile (2f)

This compound was obtained in 70% yield (1.81 g) as a white solid; mp 182–183°C; 1H NMR: δ 0.78 (t, 3H, J = 7.4 Hz, CH3), 0.91 (t, 3H, J = 7.4 Hz, CH3), 1.08–1.27, 1.32–1.39 (m, 5H, 2CH2, CH), 3.48 (d, 1H, J = 3.0 Hz, CH), 6.35 (d, 1H, J = 2.4 Hz, CH), 6.55 (dd, 1H, J = 8.4 Hz, J = 2.4 Hz, CH), 6.71 (s, 2H, NH2), 6.94 (d, 1H, J = 8.4 Hz, CH), 9.58 (s, 1H, OH); IR: 3437, 3342, 3224 (NH2, OH), 2182 (CN), 1646 cm–1 (C=C); MS: m/z (%) 258 [M]+ (1), 187 [M–71]+ (100). Anal. Calcd for C15H18N2O2: C, 69.74; H, 7.02; N, 10.84. Found: C, 69.88; H, 6.92; N, 10.71.

2-Amino-4-hexyl-7-hydroxy-4H-chromene-3-carbonitrile (2g)

This compound was obtained in 76% yield (2.07 g) as a white solid; mp 119–120°C; 1H NMR: δ 0.82 (t, 3H, J = 6.8 Hz, CH3), 0.97–1.59 (m, 10H, (CH2)5), 3.44 (t, 1H, J = 4.7 Hz, CH), 6.33 (d, 1H, J = 2.4 Hz, CH), 6.54 (dd, 1H, J = 8.4 Hz, J = 2.4 Hz, CH), 6.68 (s, 2H, NH2), 7.00 (d, 1H, J = 8.4 Hz, CH), 9.59 (s, 1H, OH); IR: 3431, 3341, 3221 (NH2, OH), 2184 (CN), 1644 (C=C); MS: m/z (%) 272 [M]+ (2), 187 [M–85]+ (100). Anal. Calcd for C16H20N2O2: C, 70.56; H, 7.40; N, 10.29. Found: C, 70.43; H, 7.37; N, 10.36.

2-Amino-4-heptyl-7-hydroxy-4H-chromene-3-carbonitrile (2h)

This compound was obtained in 68% yield (1.95 g) as a white solid; mp 117–118°C (mp 124–126°C [24]); 1H NMR: δ 0.83 (t, 3H, J = 7.0 Hz, CH3), 0.92–1.62 (m, 12H, (CH2)6), 3.44 (t, 1H, J = 4.9 Hz, CH), 6.34 (d, 1H, J = 2.4 Hz, CH), 6.54 (dd, 1H, J = 8.4 Hz, J = 2.4 Hz, CH), 6.68 (s, 2H, NH2), 7.00 (d, 1H, J = 8.4 Hz, CH), 9.02 (br.s, 1H, OH); IR: 3432, 3348, 3227 (NH2, OH), 2179 (CN), 1645 cm-1 (C=C); MS: m/z (%) 286 [M]+ (1), 187 [M–99]+ (100). Anal. Calcd for C17H22N2O2: C, 71.30; H, 7.74; N, 9.78. Found: C, 71.23; H, 7.90; N, 9.95.

Corresponding author: Ivan N. Bardasov, Ulyanov Chuvash State University, Moskovsky pr. 15, Cheboksary 428015, Russia, e-mail:

Acknowledgments:

This research was supported by the Presidential Grant of the Russian Federation for Young Scientists (MK-6312.2015.3).

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Received: 2015-4-14
Accepted: 2015-4-28
Published Online: 2015-6-2
Published in Print: 2015-6-1

©2015 by De Gruyter

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.

Articles in the same Issue

  1. Frontmatter
  2. Reviews
  3. Synthesis of quinazolines and quinazolinones via palladium-mediated approach
  4. Media with photoinduced irreversible fluorescence
  5. Synthesis of quinolines and acridines by the reaction of 2-(perfluoroalkyl)anilines with lithium and Grignard reagents
  6. Preliminary Communications
  7. Synthesis of tricyclic indolizidines from ethyl isocyanoacetate
  8. Ligand- and catalyst-free intramolecular C-S bond formation: direct access to indalothiochromen- 4-ones
  9. Research Articles
  10. Preparation of optically active 4-substituted γ-lactones by lipase-catalyzed optical resolution
  11. One-pot synthesis of 4-alkyl-2-amino-4H-chromene derivatives
  12. Ring transformation and antimicrobial activity of indolyl-substituted 2(3H)-furanones
https://doi.org/10.1515/hc-2015-0077
Keywords for this article
cyano compounds; heterocycles; Knoevenagel condensation; Michael addition; pyrans
Creative Commons
BY-NC-ND 3.0

Articles in the same Issue

  1. Frontmatter
  2. Reviews
  3. Synthesis of quinazolines and quinazolinones via palladium-mediated approach
  4. Media with photoinduced irreversible fluorescence
  5. Synthesis of quinolines and acridines by the reaction of 2-(perfluoroalkyl)anilines with lithium and Grignard reagents
  6. Preliminary Communications
  7. Synthesis of tricyclic indolizidines from ethyl isocyanoacetate
  8. Ligand- and catalyst-free intramolecular C-S bond formation: direct access to indalothiochromen- 4-ones
  9. Research Articles
  10. Preparation of optically active 4-substituted γ-lactones by lipase-catalyzed optical resolution
  11. One-pot synthesis of 4-alkyl-2-amino-4H-chromene derivatives
  12. Ring transformation and antimicrobial activity of indolyl-substituted 2(3H)-furanones
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