Orthoamide, XXVI. Synthese und Reaktionen von 1,2‐ Bis(dialkylamino)äthylenen

Abstract

Eingegangen a m 18. Dezember 1973 CHz-aktive Dimethylaminomethylen-Verbindungen bilden mit dem Aminal-rert-butylester 2 1,2-Bis(dimethylamino)Bthylene 3. Eine Umaminierung von 3 erfolgt nur an der 2-Dimethylamino-Gruppe Unter saurer Katalyse. 1 -Benzoyl-(3d, I -Cyan-(3d) und l-khoxycarbonyl-I ,2-bis(dimethylamino)iithylen (3e) reagieren rnit Amidinen, Guanidin sowie Thioharnstoff unter RingschluD zu den entsprechenden 5-Dimethylaminopyrimidinen (9n-f, 11). rnit Hydrazin entsteht 4-Dimethylamino-3-phenylpyrazol (10). Orthoamides, XXVI 1)Synthesis and Reactions of 1 f-Bis(dialkylamlno)ethyleres CH-active dimethylaminomethylene compounds react with the aminal rerr-butyl ester 2 to give I ,2-bis(dimethylamino)ethylenes (3). Reamination of 3 takes place only in the presence of an acid catalyst and only a t the 2-dimethylamino group. I-Benzoyl-(3a), I-cyano-(3d), and 1 -ethoxycarbonyl-I ,2-bis(dimethylamino)ethylene (3e) undergo cyclization with amidines, guanidine, or thiourea to give the corresponding 5-dimethylaminopyrimidines (9a -f, 11) and with hydrazine to yield 4-dimethylamino-3-phenylpyrazole (10).Bis(dialky1amino)Bthylene wurden erstmals 1959 durch Umsetzung von a-Halogenaldehyden rnit sekundaren Aminen erhalten,). yz!

A practical multi-step synthesis of ethyl N-functionalized $$\varvec{\upbeta }$$ β -amino benzimidazole acrylate derivatives as promising cytotoxic agents

“…With the hydrochloride salts of mono N-substituted diamines 11(a-p) in hand, our focus was the transformation of ethyl 3-dimethylamino-2-(1H-benzimidazol-2-yl)acrylate 5 into desired compounds 12 by transamination. Typically, the mechanism of this reaction is an additionelimination [18] after the loss of dimethylamine via an aminal intermediate, which could not be isolated [13]. In previous work, we used 5 as an ambident synthon in a regioselective azaannulation with isocyanate for the preparation of 1-oxo-1,2-dihydropyrimido[1,6-a]benzimidazole-4-carboxylates using solvent-free conditions under microwave irradiation [19].…”