Enaminones as building blocks in organic synthesis: a novel route to polyfunctionally substituted benzonitriles, pyridines, eneylbenzotriazoles and diazepines

摘要

An efficient synthesis of enaminones la-c is reported. Compounds la-c reacted with diethyl-3-amino-2-cyanopenten-1,5-dicarboxylate (3) to yield the benzonitriles 6. On the other hand, the reaction of la-c with 3-amino-2-cyano-2-pentene dinitrile (7) afforded a mixture of benzonitriles 10 and pyridines 9. The reaction of la-c with 3-aminocrotononitrile 11 has afforded the 4-substituted-3-cyano-2-methylpyridines 15a-c. The reaction of ethylene diamine with la-c afforded 5-substituted-2,3-dihydro-1H-[1,4]diazepines 18a-c. On the other hand, la-c reacted with o-phenylenediamine to yield the 4-(2-aminopheynlamino)-substituted enaminones 21. Compounds 21 could be converted into the benzotriazolylenones 22 on treatment with sodium nitrite in acetic acid solution. [References: 12]