Triethylamine → tert-Butyl 4-chloro-5,6-dihydropyrido(4',3':4,5)thieno(2,3-d)pyrimidine-7(8H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a of mixture of POCl3 (30 mL) and triethylamine (50 mL) at 0° C. was added 4-oxo-3,5,6,8-tetrahydro-4H-9-thia-1,3,7-triaza-fluorene-7-carboxylic acid tert-butyl ester (10.0 g). The reaction mixture was heated at 60° C. for 3 h. Water was then added, followed by sodium bicarbonate to neutralize the reaction mixture. The resulting mixture was extracted with dichloromethane. The organic layer was concentrated and the crude compound was purified by silica gel column chromatography using a mixture of hexanes:ethyl acetate (10:1) to give the title compound (3.1 g, 25%). 1H NMR (400 MHz, CDCl3): δ 8.70 (s, 1H), 4.69 (s, 2H), 3.74 (t, 2H, J=5.6 Hz), 3.14-3.18 (brs, 2H), 1.46 (s, 9H). LC-MS (ESI) m/z 326.0 (M+H).

Provenance & Evidence