Synthesis of 1-aminophosphonic acid derivatives via (acylimino)phosphonic esters.
In: Synthesis, (1986) ; Nr. 5, S. 372-375
Zeitschriftenaufsatz / Fach: Chemie
Photobromination of RCONHCH2P(O)(OEt)2 (R = Ph, p-ClC6H4, OCH2CCl3) with N-bromosuccinimide in CCl4 gave 70-95% RCONHCHBrP(O)(OEt)2 (I), which was dehydrobrominated with tertiary amines to give RCON:CHP(O)(OEt)2, which reacted in situ with nucleophiles such as enamines, ynamines, and Grignard reagents to give RCONHCHR1P(O)(OEt)2 (R = same as above, R1 = BzCH2, Et2NCOCHMe, 1-naphthyl, H2C:CH, PhC.tplbond.C, etc.). Reaction of I with P(OR2)3 (R2 = Me, Et), gave 56-90% RCONHCH[P(O)(OR2)2]P(O)(OEt)2.