Triphenyl phosphite → (S)-methyl 4-isopropyl-3-methyl-2-oxo-1,2,3,4-tetrahydropyrido[3,2-b]pyrazine-7-carboxylate

Participants

Reaction Steps

(S)-methyl 6-((1-ethoxy-1-oxopropan-2-yl)(isopropyl)amino)-5-nitronicotinate (0.900 g, 2.65 mmol) was dissolved in dichloromethane (10 mL). To this solution was added triphenyl phosphite (3.0 mg, 9.7 umol), ammonium metavanadate (30 mg, 0.265 mmol) and Pt/C (5% wt., 0.120 g). The reaction mixture was hydrogenated at 80 psi at 25° C. for 6 h. The mixture was filtered through a small pad of celite and the pad was washed with dichloromethane (20 mL). The combined filtrates were concentrated in vacuo and crystallized with ethyl ether to afford the title compounds as a white solid (0.658 g, 94%). 1H NMR (400 MHz, CHLOROFORM-d) δ (ppm): 1.33 (d, J=6.82 Hz, 3H) 1.36-1.41 (m, 6H) 3.90 (s, 3H) 4.34 (q, J=6.65 Hz, 1H) 4.86 (m, 1H) 7.52 (d, J=1.77 Hz, 1H) 8.59 (d, J=1.77 Hz, 1H) 8.73 (br. s., 1H); [M+H] calc'd for C13H17N3O3, 264. found 264.

Provenance & Evidence