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

An efficient synthesis of enaminones 1a‐c is reported. Compounds 1a‐c reacted with diefhyl‐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‐lH‐[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.