Studies on the syntheses of heterocycles from 3-arylsydnone-4-carbohydroximic acid chlorides with N-arylmaleimides, [1,4]naphthoquinone and aromatic amines

摘要

3-Arylsydnone-4-carbohydroximic acid chlorides (1) could react with N-arylmaleimides (3a-b) or 2-methyl-N-phenylmaleimide (3c) to give 3-(3-arylsydnon-4-yl)-5-aryl-3a,6a-dihydro-pyrrolo[3,4-d]isoxazole-4,6-dio nes (4a-h) or 6a-methyl-3-(3-arylsydnon-4yl)-5-phenyl-3a,6a-dihydro-pyrrolo[3,4-d]isoxaz ole-4,6-diones (4i-1), respectively. However, 3-(arylsydnon-4-yl)-naphtho[2,3-d]isoxazole-4,9-diones (6a-d) were obtained in good yield by the reaction of carbohydroximic acid chlorides 1 with [1,4]naphthoquinone. Furthermore, 2-(3-arylsydnon-4-yl)benzoxazoles (9a-d) and 2-(3-arylsydnon-4-yl)benzothiazoles (9e-h) were obtained via the reaction of carbohydroximic acid chlorides 1 with ortho-substituted aromatic amines 7a and b. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 31]