Ethanol → HCID 12953041, compound

Participants

Reaction Steps

A mixture of 3,10-dihydro-10-oxo-1H-pyrido[1,2-a]thieno[3,4-d]pyrimidine-7-carboxylic Acid (15 g., 0.06 mol) and 1,1' carbonyldiimidazole (9.8 g, 0.06 mol) in dimethylformamide (12 ml) and tetrahydrofuran (700 ml) is refluxed with stirring for 3 hours. Absolute ethanol (20 ml) is added and refluxing is continued for a further 3 hours. The solvents are removed under reduced pressure. The residue is shaken with hot 0.5 mol aqueous sodium bicarbonate (200 ml), cooled and filtered. The residue is washed several times with water and recrystallized from methanol to give the product (8.9 g.) mp 183°-185° C.

Provenance & Evidence