A convenient one-pot synthesis of 4-amino-3-arylpyrazoles from α-phthaloylaminoacetophenones
摘要:
Condensation of alpha-phthaloylaminoacetophenones 1a-c with N,N-dimethylformamide dimethyl acetal afforded the novel enamines 3a-c. Cyclization of 3 with hydrazine, alkylhydrazine or phenylhydrazine salts (4a-d) gave 4-phthaloylamino-3-arylpyrazoles 7-9 in high yields. Deprotection of 7-9 was accomplished with hydrazine to provide 4-amino-3-arylpyrazoles 5 in good yields. (C) 1998 Elsevier Science Ltd. All rights reserved.
A convenient one-pot synthesis of 4-amino-3-arylpyrazoles from α-phthaloylaminoacetophenones
摘要:
Condensation of alpha-phthaloylaminoacetophenones 1a-c with N,N-dimethylformamide dimethyl acetal afforded the novel enamines 3a-c. Cyclization of 3 with hydrazine, alkylhydrazine or phenylhydrazine salts (4a-d) gave 4-phthaloylamino-3-arylpyrazoles 7-9 in high yields. Deprotection of 7-9 was accomplished with hydrazine to provide 4-amino-3-arylpyrazoles 5 in good yields. (C) 1998 Elsevier Science Ltd. All rights reserved.