Unconventional nucleotide analogues. Part IX. N-substituted 3-( pyrimidin-1-yl)pyrrolidin-2-ones

Abstract

Hubert–Johnson reaction of the 2,4-diethoxypyrimidines (2a and b) with 2-bromobutyrolactone (3), followed by hydrolysis of the coupling products (4a and b), gave the pyrimidin-1-yl lactones (5a and b). 2-(1,2,3,4-Tetra-hydro-2,4-dioxopyrimidin-1 -yl)butyrolactone (5a) was converted into the N-vinyipyrrolidin-2-one analogue (11)via a five-step reaction sequence [(5a)→(7a)→(7b)→(8)→(10c)→(11)]. Polymerisation of the product (11) yielded material (12)(mol. wt. 80,000) which, in aqueous solution, exhibited a pronounced (25%) hypochromicity effect at 263 nm.