Synthesis and characterization of some 2-(1-phenyl-3- (thiophen-2-yl)- 1H-pyrazol-4-yl)- 4H-chromon-4-ones, 4-(2-hydroxyphenyl)- 6-(1-phenyl-3-(thiophen-2-yl)- 1H-pyrazol-4-yl)pyrimidine -2-(1H)-thione, 2-(5-(1-phenyl-3- (thiophen-2-yl)-1H-pyrazol-4-yl)- 1H-pyrazol-3-yl)phenol and 2-(2,3-dihydro-2-(1-phenyl-3- (thiophen-2-yl)-1H-pyrazol-4-yl)- benzo[b][1,4] thiazepin-4-yl)-phenol

Abstract

Oxidative cyclization of 1 with DMSO-I₂ yields 2-(1-phenyl-3-(thiophen-2-yl)-1H- pyrazol-4-yl)-4H-chromon-4-one 2. Compound 2 reacts with thiourea in the presence of potassium hydroxide to form 4(2-hydroxyphenyl)-6- (1-phenyl-3-(thiophen-2-yl)-1H- pyrazol-4-yl)pyrimidine-2-(1H)-thione 3. Compound 2 is refluxed in ethanol with hydrazine hydrate and KOH to afford 2-(5-(1-phenyl-3-(thiophen-2-yl)- 1H-pyrazol-4-yl)- 1H-pyrazol-3-yl)phenol 4. Compound 1 when treated with 2-amino thiophenol affords 2-(2,3-dihydro-2-(1-phenyl-3- (thiophen-2-yl)-1H-pyrazol-4-yl)- benzo[b][1,4]thiazepin-4-yl)-phenol 5.