Amberlyst A21: A reusable solid catalyst for green synthesis of pyran annulated heterocycles at room temperature

Screening of a library of 4-aryl/heteroaryl-4H-fused pyrans for xanthine oxidase inhibition: synthesis, biological evaluation and docking studies

“…In each occasion, the spectral data ( 1 H and 13 C NMR) of known compounds were compared with that reported in the literature. 6,7,-phenyl-4H-chromene-3-carbonitrile (1a) (Yu and Da-Ming, 2012;Xu et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(4-fluorophenyl)-5-oxo-4H-chromene-3-carbonitrile (1b) (Yu and Da-Ming, 2012), 2-amino-5,6,7,8-tetrahydro-4-(4-bromophenyl)-5-oxo-4H-chromene-3-carbonitrile (1c) (Yu and Da-Ming, 2012), 2-amino-5,6,7,8- (Xu et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(4-methoxyphenyl)-5-oxo-4H-chromene-3-carbonitrile (1i) (Xu et al, 2011;Rostamnia and Morsali, 2014), 2-amino-5,6,7,8-tetrahydro-4-(4-nitrophenyl)-5-oxo-4H-chromene-3-carbonitrile (1j) (Yu and Da-Ming, 2012;Xu et al, 2011;Rostamnia and Morsali, 2014;HosseiniMonfared et al, 2013), 2-amino-5,6,7,8-tetrahydro-4-(4-hydroxyphenyl)-5-oxo-4H-chromene-3-carbonitrile (1k) (Xu et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(furan-2-yl)-5-oxo-4H-chromene-3-carbonitrile (1m) (Xu et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(3,4-dimethoxyphenyl)-5-oxo-4H-chromene-3-carbonitrile (1q) (Yu and Da-Ming, 2012;Xu et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(4-chlorophenyl)-5-oxo-4H-chromene-3-carbonitrile (1s) (Yu and Da-Ming, 2012;Rostamnia and Morsali, 2014;HosseiniMonfared et al, 2013), 2-amino-5,6,7,8-tetrahydro-4-(3-nitrophenyl)-5-oxo-4H-chromene-3-carbonitrile (1v) (Xu et al, 2011), 2-amino-5,6,7,8-tetrahydro-7,7-dimethyl-5-oxo-4-phenyl-4H-chromene-3-carbonitrile (2a) (Kumar et al, 2009;Sadegh and Ali, 2014;Yu and Da-Ming, 2012;Gao et al, 2008;Hasaninejad et al, 2013;Jiang-Cheng et al, 2011;Bihani et al, 2013;Khaksar et al, 2012;Banerjee et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(4-fluorophenyl)-7,7-dimethyl-5-oxo-4H-chromene-3-carbonitrile (2b) …”

“…methoxyphenyl)-7,7-dimethyl-5-oxo-4H-chromene-3-carbonitrile (2h)(Yu and Da-Ming, 2012; Jiang-Cheng et al, 5-oxo-4H-chromene-3-carbonitrile (2i)(Kumar et al, 2009;Jiang-Cheng et al, 2011;Bihani et al, 2013;Khaksar et al, 2012;Banerjee et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(4-nitrophenyl)-7,7-dimethyl-5-oxo-4H-chromene-Fig. 4 a Binding poses of R-enantiomer (brown) and S-enantiomer (green) in binding cavity of XO.…”

“…oxo-4H-chromene-3-carbonitrile (2s)(Sadegh and Ali, 2014;Yu and Da-Ming, 2012;Gao et al, 2008;Jiang-Cheng et al, 2011;Bihani et al, 2013;Khaksar et al, 2012; Ban- erjee et al, 2011), 2-amino-5,6,7,8-tetrahydro-4-(3-nitro- phenyl)-7,7-dimethyl-5-oxo-4H-chromene-3-carbonitrile (2v) (Kumar et al, 2009;Yu and Da-Ming, 2012;Jiang-Cheng et al, 2011;Bihani et al, 2013;Khaksar et al, 2012; Ban- erjee et al, 2011), 6-amino-2,4-dihydro-3-methyl-4-phenylpyrano[2,3-c]pyrazole-5-carbonitrile (3a)(Ali and El- Remaily, 2013;Paul et al, 2013;Bora et al, 2013;Bolligarla and Das, 2011;Bihani et al, 2013), 6-amino-2,4-dihydro-4-(4-fluorophenyl)-3-methylpyrano[2,3-c]pyrazole-5-carbonitrile (3b)(Ali and El-Remaily, 2013;Bora et al, 2013), 6-amino-2,4-dihydro-4-(3-hydroxyphenyl)-3-methylpyrano[2,3-c]pyrazole-5-carbonitrile (3c)3g)(Ali and El-Remaily, 2013;Paul et al, 2013;Bora et al, 2013), 6-amino-2,4-dihydro-4-(4-methoxyphenyl)-3-methylpyrano[2,3-c]pyrazole-5-carbonitrile (3i)(Ali and El- Remaily, 2013;Paul et al, 2013;Bora et al, 2013;Bolligarla and Das, 2011;Bihani et al, 2013), 6-amino-2,4-dihydro-4-(4-nitrophenyl)-3-methylpyrano[2,3-c]pyrazole-5-carbonitrile (3j)(Ali and El-Remaily, 2013;Bolligarla and Das, 2011;Bihani et al, 2013), 6-amino-2,4-dihydro-4-(4-hydroxyphenyl)-3-methylpyrano[2,3-c]pyrazole-5-carbonitrile (3k)(Ali and El- Remaily, 2013;Bolligarla and Das, 2011;Bihani et al, 2013), 6-amino-2,4-dihydro-4-(naphthalen-2-yl)-3-methylpyrano[2,3- c]pyrazole-5-carbonitrile (3l)…”

Synthesis of N-hydroxysuccinimide from succinic acid and hydroxylammonium chloride using Amberlyst A21 as reusable solid base catalyst

“…The use of solid base catalysts is continuously expanding because of its many advantages regarding economic and environmental problems compared to that of liquid bases [11]. Along with the development in solid base catalysts, more recently, resin-bound catalysts have been becoming more and more important in organic synthesis due to their recyclability, ease of separation and purification, and higher safety feature against potential explosive reagents [12]. Many kinds of ion-exchange resins, namely Amberlyst, Amberlite, and Dowex are now available at low cost, the greater diversity of functionalities, and higher loading capacities [13].…”

An Efficient and More Sustainable One-Step Continuous-Flow Multicomponent Synthesis Approach to Chromene Derivatives

“…Using this direct approach, several homogeneous and heterogeneous catalysts, such as L-proline [7], thiourea dioxide [8], magnesium oxide [9], 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) [10], glycerol [11], and ionic liquids [12] have been explored for the synthesis of these molecules under batch reaction conditions. Recently, guanidine supported on magnetic nanoparticles [13], hydroxyapatites [14], and Amberlyst A21 [15] have also been employed for the synthesis of these molecules in labscale batch setup.…”