ethyl 9',10'-difluoro-8'-nitro-7'-oxospiro[cyclobutane-1,3'(2'H)-[7H]pyrido[1,2,3-de][1,4]benzoxazine]-6'-carboxylate → Ethyl 8'-amino-9',10'-difluoro-7'-oxospiro-[cyclobutane-1,3'(2'H)-[7H]pyrido[1,2,3-de][1,4]benzoxazine]-6'-carboxylate

Participants

Reaction Steps

A solution of ethyl 9′,10′-difluoro-8′-nitro-7′-oxospiro[cyclobutane-1,3′(2′H)-[7H]pyrido[1,2,3-de][1,4]benzoxazine]-6′-carboxylate (580 mg, 1.53 mmol) in DMF (30 mL) was treated with hydrogen under atmospheric pressure over 10% Pd/C (60 mg) at 50° C. for 3 hours. The catalyst was removed by filtration with Celite and the filtrate was poured into ice-water. The resulting precipitate was stirred for 1 hour and collected by filtration, washed with water and dried to yield the title compound (468 mg, 88%) as a pale yellow solid. 1H-NMR (400 MHz, DMSO-d6) δ 1.29 (3H, t, J=7.3 Hz), 1.92-2.02 (2H, m), 2.10-2.19 (2H, m), 2.61-2.69 (2H, m), 4.23 (2H, q, J=7.3 Hz), 4.39 (2H, s), 7.38 (2H, brs), 8.65 (1H, brs). ESIMS (+): 351 [M+H]+.

Provenance & Evidence