Aldol-type and Claisen Condensation Reactions of 1,3,6- and 1,3,7-Trimethyllumazines

Abstract

Various side-chain modifications of 6- and 7-substituted 1,3-dimethyl-lumazines are described. Wittig reactions with 1.3-dimelhyllumazin-6- (13) and 1,3-dimethyllumazin-7-yl-methyltriphenyIphosphonium bromide (10) Icad to styryl derivates (8, 9, 14) as well as a variety of structural analoges 15 - 27. Compound 10 could be converted by DBU in the stable 1,3-dimethyllumazin-7-yl-triphenylphosphoniumylide (11). 1,3.6-Trimethyl- (1) and 6-benzyl 1,3-dimethyllumazine (29) have been subject for Claisen-condensations with etbyl Oxalate to give 28 and 30 1,3-Dimethyllumazme-6-carbonylchloride (33) reacted well with the ethoxy-magnesium salt of ethyl malonatc. ethyl cyanoacctate, ethyl acetacetate and malononitrilc to form elongated side-chains (34 - 37).

Keywords

• lumazines synthesis
• claisen condensation