Carbon Dioxide → 1-(3,5-difluorophenyl)-2-(6-carboxymethyl-2,3-dihydro-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one

Participants

Reaction Steps

Lithium bis(trimethylsilyl)amide (1.5 ml of 1.0M solution) was added to a solution of 1-(3,5-difluorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one (0.5 g) in tetrahydrofuran, under inert atmosphere at -5° C. After stirring for 0.5 hours, the solution was poured onto solid carbon dioxide (excess), allowed to warm to ambient temperature and poured onto water. The aqueous phase was acidified, extracted (ethyl acetate), dried (magnesium sulphate) and evaporated, to give 1-(3,5-difluorophenyl)-2-(6-carboxymethyl-2,3-dihydro-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one (Compound 704, 0.065 g), NMR 1.5 (s,6H), 3.2 (s,2H), 5.4 (s,2H), 6.8 (m,1H), 7.0 (m,2H), 7.2 (m,3H), 7.5 (d,2H), 9.0 (bs,1H).

Provenance & Evidence