Selective reductions of substituted #alpha#-(1,2,4-triazol-1-yl)chalcones with NaBH_4 and Al-isopropoxide: Synthesis of substituted (+-)#alpha#-(4-chlorophenyl)-#beta#-(phenylmethylene)-1H-1,2,4-triazole-1-ethanols having potential bacteriostatic and

摘要

The title compounds 2a-i have been synthesised by two methods, Method 1 involves reduction of substituted 1,3-diphenyl-2-(1,2,4-triazol-1-yl)prop-2-en-1-ones (i.e. #alpha#-triazolylchalcones) 1a-i with NaBH_4 in methanol at 0 deg C with excellent yield (81-97 %) with retention of double bond. For comparison these alcohols 2a-i are also prepared by the classical Method 2 which involves selective reduction of ketones 1a-i with aluminium isopropoxide in toluene giving 2a-i with 28-56% yield. The method 1 is superior to method 2 in the respect of higher yields, shorter reaction time and higher purity. Compounds 2a-i have been assessed for their fungicidal activity against rice fungus, Pyricularia oryzae and Botrytis cinerea while their bacteriostatic action evaluated against Staphylococcus aureus and Salmonella typhi. All compounds 2a-i have been found to have fungicidal activity against P. oryaze (Table III) and bacteriostatic activity against S. aureus and S. typhi at 100 #mu#g/mL. (Table IV)