Triphenyl phosphite → Methyl 6-oxo-5,6,6a,7,9,10-hexahydropyrido[3,2-e][1,4]thiazino[4,3-a]pyrazine-3-carboxylate

Participants

Reaction Steps

Ethyl 4-(5-(methoxycarbonyl)-3-nitropyridin-2-yl)thiomorpholine-3-carboxylate (600 mg g, 1.69 mmol) was dissolved in dichloromethane (5 mL). To the yellow solution was added ammonium metavanadate (10.0 mg, 0.085 mmol), triphenyl phosphite (aprox 10 ul, 0.032 mmol), and Pt/C (50 mg, 5% w/w). The reaction mixture was pressurized with hydrogen gas (110 psi) and stirred at room temperature for 16 h. The reaction was then depressurized and diluted with dichloromethane (20 mL) which was refluxed for 30 min. The hot solution was filtered through a pad of celite and washed with hot dichloromethane (3×10 mL). The filtrate was concentrated to yield the title compound (452 mg, 96%) as a white solid. [M+H] calc'd for C, 12; H, 13; N, 3; O, 3; S, 280; found, 280.

Provenance & Evidence