Methyl 9-benzyloxy-2-(3-chlorobenzyl)-1,8-dioxo-1,3,4,8-tetrahydro-2H-pyrido[1,2-a]pyrazine-7-carboxylate → 9-benzyloxy-2-(3-chlorobenzyl)-1,8-dioxo-1,3,4,8-tetrahydro-2H-pyrido[1,2-a]pyrazine-7-carboxylic acid

Participants

Reaction Steps

Methyl 9-benzyloxy-2-(3-chlorobenzyl)-1,8-dioxo-1,3,4,8-tetrahydro-2H-pyrido[1,2-a]pyrazine-7-carboxylate (420 mg) was dissolved in tetrahydrofuran (8 ml)-water (2 ml), and 4N aqueous lithium hydroxide solution (0.58 ml) was added with stirring. After stirring at 70° C. for 1 hr, the mixture was concentrated. Water (5 ml) and then 5% aqueous potassium hydrogen sulfate solution (15 ml) were added with stirring. The precipitated crystals were collected by filtration to give 9-benzyloxy-2-(3-chlorobenzyl)-1,8-dioxo-1,3,4,8-tetrahydro-2H-pyrido[1,2-a]pyrazine-7-carboxylic acid (352 mg).

Provenance & Evidence