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

A mixture of 2-amino-4,7-dihydro-5H-thieno[2,3-c]pyridine-3,6-dicarboxylic acid 6-tert-butyl ester 3-ethyl ester (18.5 g) and formamidine acetate (8.85 g) in DMF (100 mL) were heated at 100° C. for 16 h. The reaction mixture was cooled and concentrated. The residues was partitioned between water and ethyl acetate. The organic layer was washed with water 3 times and concentrated to give the title compound (15.8 g, 90%). 1H NMR (400 MHz, CDCl3): δ 7.88 (s, 1H), 4.56-4.62 (brs, 2H), 3.62-3.70 (brs, 2H), 3.02-3.08 (brs, 2H), 1.42 (s, 9H). LC-MS (ESI) m/z 308.1 (M+H).

Provenance & Evidence