An Efficient Synthesis of Novel Hexahydropyrido[2,3-<i>d</i>]pyrimidine Derivatives from (Arylmethylidene)pyruvic Acids (=(3<i>E</i>)-4-Aryl-2-oxobut-3-enoic Acids) in Aqueous Media
作者:Saeed Balalaie、Shahrzad Abdolmohammadi、Bita Soleimanifard
DOI:10.1002/hlca.200800318
日期:2009.5
Abstractmagnified imageA series of new hexahydropyrido[2,3‐d]pyrimidine derivatives 3 were synthesized by the cyclocondensation reaction of (arylmethylidene)pyruvic acids (=(3E)‐4‐aryl‐2‐oxobut‐3‐enoic acids) 1 and 6‐aminouracils (=6‐aminopyrimidine‐2,4(1H,3H)‐diones) 2 in H2O under reflux conditions (Scheme 1, Table). This novel protocol has the advantages of facility, of easy workup, of high yields, and of an environmentally benign procedure. The structures of compounds 3a–3f were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS). A plausible mechanism for the reaction is proposed (Scheme 2).