Green synthesis of 2-amino-7-hydroxy-4-aryl-4$H$-chromene-3-carbonitriles using ZnO nanoparticles prepared with mulberry leaf extract and ZnCl$_{2}$
A highly efficient and environmentally benign protocol for the synthesis of 2-amino-7-hydroxy-4-aryl-4$H$-chromene-3-carbonitrile derivatives in good to high yields (77%-97%) by one-pot three-component coupling reaction of aromatic aldehydes, malononitrile, and resorcinol under reflux condition was developed in aqueous media using ZnO nanoparticles that were prepared in the presence of mulberry leaf extract under mild conditions.
Green synthesis of 2-amino-7-hydroxy-4-aryl-4$H$-chromene-3-carbonitriles using ZnO nanoparticles prepared with mulberry leaf extract and ZnCl$_{2}$
A highly efficient and environmentally benign protocol for the synthesis of 2-amino-7-hydroxy-4-aryl-4$H$-chromene-3-carbonitrile derivatives in good to high yields (77%-97%) by one-pot three-component coupling reaction of aromatic aldehydes, malononitrile, and resorcinol under reflux condition was developed in aqueous media using ZnO nanoparticles that were prepared in the presence of mulberry leaf extract under mild conditions.
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- 23 23 18 19 22 present work 93 3. Experimental
- Preparation of ZnO nanoparticles
- General procedure for synthesis of 2-amino-7-hydroxy-4-aryl-4H -chromene-3-carbonitriles
- 2-Amino-7-hydroxy-4-phenyl-4H -chromene-3-carbonitrile (Table 2, Product a):
- 1H NMR (400 MHz, DMSO-d6) : δ = 4.63 (s, 1H, CH), 6.40–6.51 (m, 2H), 6.80 (d, J = 8.5 Hz, 1H), 6.96 (s, 2H, NH2) , 7.18–7.30 (m, 5H), 9.73 (s, 1H, OH) ppm;
- 13C NMR (100 MHz, DMSO-d
- 6) : δ = 54.1, 102.3, 112.6, 113.8, 120.1, 126.9, 127.5, 128.9, 129.8, 146.2, 148.8, 157.5, 160.1 ppm. Anal. Calcd. for C16H12N2O2: C, 72.72; H, 4.58; N, 10.60%. Found: C, 72.87; H, 4.69; N, 10.84%;
- 2-Amino-4-(4-chlorophenyl)-7-hydroxy-4H -chromene-3-carbonitrile (Table 2, Product c): 1H NMR (400 MHz, DMSO-d6) : δ = 4.67 (s, 1H, CH), 6.41–6.51 (m, 2H), 6.79 (d, J = 8.4 Hz, 1H), 6.94 (s, 2H, NH2) , 7.19 (d, J = 8.0 Hz, 2H), 7.36 (d, J = 8.0 Hz, 2H), 9.75 (s, 1H, OH) ppm;13C NMR (100 MHz, References
- 2-Amino-7-hydroxy-4-p-tolyl-4H -chromene-3-carbonitrile (Table 2, Product n):1H NMR (400 MHz, DMSO-d6) : δ = 2.27 (s, 3H), 4.69 (s, 1H, CH), 6.41–6.52 (m, 2H), 6.79 (d, J = 8.4 Hz, 1H), 6.95 (s, 2H, NH2) , 7.09 (d, J = 8.3 Hz, 2H), 7.27 (d, J = 8.3 Hz, 2H), 9.71 (s, 1H, OH) ppm;
- 13C NMR (100 MHz, DMSO-d6) : δ = 21.2, 49.6, 57.3, 113.1, 113.6, 114.8, 119.2, 126.7, 129.3, 132.1, 139.7, 141.4, 155.7, 158.7, 163.3 ppm. Anal. Calcd. for C17H
- N2O2: C, 73.37; H, 5.07; N, 10.07%. Found: C, 73.51; H, 5.25; N, 10.30%