Formamidine acetate → tert-Butyl 4-oxo-3,5,6,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidine-7(4H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-tert-butyl 3-ethyl 2-amino-4,7-dihydrothieno[2,3-c]pyridine-3,6(5H)-dicarboxylate from Example 9A (1.23 kg, 3.77 mol) in DMF (10.3 L) was added formamidine acetate (588 g, 5.65 mol). The mixture was heated to 100° C. overnight. The solvent was removed in vacuo. The residue was stirred with ethyl acetate (3 L) for 2 h. The precipitate was collected by suction filtration and rinsed with ethyl acetate. The solid was dried to yield 1.02 kg (88%) of the title compound.

Provenance & Evidence