Reagents for Bioorganic Synthesis: Preparation, Properties, and Reactions of Ethyl and Methyl N-(Cyanomethyl)methanimidates

Article abstract of DOI:10.1021/jo00181a014

An efficient procedure for the preparation of the reagents ethyl and methyl N-(cyanomethyl)methanimidates (NCCH2N=CHOR) (1a, R=Et; 1b, R=Me) is presented,along with their preliminary properties and reactions.The reaction of aminoacetonitrile hydrochloride with trialkyl orthoformate gave 4(5)-imidazolone.The reaction of aminoacetonitrile (free base) with the ortho ester, catalyzed by formic acid, gave methyl N-7H-imidazo<1.5-a>imidazol-2-ylmethanimidate (6).The reaction of 1b with 2-aminothiazole and 2-aminopyrimidine, catalyzed by trimethylsilyl triflate, gave 2-(5'-imino-2'-imidazolin-1'-yl)thiazole (9) and 2-(5'-imino-2'-imidazolin-1'-yl)pyrimidine (10), respectively.Compound 10 underwent facile acid hydrolysis to form 2-(formylamino)pyrimidine (11).The reactions of 2-aminothiazole with 2 equiv of 1b or that of 10 with 1 equiv of 1b both provided 2-<5'-(5''-imino-2''-imidazolin-1''-yl)imidazol-1'-yl>thiazole (12).