New approach to 5-arylsulfonyl-substituted 1,2-dihydropyrimidin-2-ones via base-induced chloroform elimination from 4-trichloromethyl-1,2,3,4-tetrahydropyrimidin-2-ones
摘要:
A four-step method for the synthesis of 5-arylsulfonyl-substituted 1,2-dihydropyrimidin-2-ones has been developed. The reaction of readily available N-[(1-acetoxy-2,2,2-trichloro)ethyl]ureas with sodium enolates of alpha-arylsulfonylketones followed by heterocyclization dehydration of the oxoalkylureas formed gave 5-arylsulfonyl-4-trichloromethyl-1,2,3,4-tetrahydropyrimidin-2-ones. The latter, in the presence of strong bases, eliminate CHCl3 to give the target compounds. (C) 2010 Elsevier Ltd. All rights reserved.
A novel convenient synthesis of 5-acyl-1,2-dihydropyrimidin-2-ones via 4-trichloromethyl-1,2,3,4-tetrahydropyrimidin-2-ones
摘要:
A novel four-step methodology for the synthesis of 5-acyl-1,2-dihydropyrimidin-2-ones has been developed. The reaction of readily available N-[(1-acetoxy-2,2,2-trichloro)ethyl]ureas with Na-enolates of 1,3-diketones or beta-oxoesters followed by heterocyclization-dehydration of the oxoalkylureas formed gave 5-acyl-4-trichloromethyl-1,2,3,4-tetrahydtopyrimidin-2-ones. The latter, in the presence of NaH, eliminate CHCl3 to give the target compounds. (C) 2009 Elsevier Ltd. All rights reserved.