1,1'-Carbonyldiimidazole → (3S,11aR)-N-(2,4-difluorobenzyl)-6-methoxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydrooxazolo[3,2-d]pyrido[1,2-a]pyrazine-8-carboxamide

Participants

Reaction Conditions

Reaction Steps

(3S,11aR)-3-Methyl-6-(methyloxy)-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxylic acid (3.00 g) and 1,1′-carbonyldiimidazole (CDI) (2.15 g) were slurried in 1,2-dimethoxyethane (DME) (30 mL). The mixture was heated to 80° C. for 1 h. The resulting solution was cooled to 20° C., then treated with 2,4-difluorobenzylamine (1.45 mL). After stirring for 1 h, the mixture was quenched with water (30 mL) and DME was removed under reduced pressure. The product was collected by filtration and dried in a vacuum oven overnight at 50° C. The product was obtained as a solid.

Provenance & Evidence