Triphenyl phosphite → 10-Oxo-1,3,4,9,10,10a-hexahydro-2,4-a,5,9-tetraaza-phenanthrene-2,7-dicarboxylic acid 2-tert-butyl ester 7-methyl ester

Participants

Reaction Steps

To a suspension of 4-(tert-butoxycarbonyl)piperazine-2-carboxylic acid (1169 mg, 5.08 mmol) in THF (46 mL) was added methyl 6-chloro-5-nitronicotinate (1000 mg, 4.62 mmol) and K2CO3 (638 mg, 4.62 mmol). The suspension was heated to reflux for 2 hours, cooled to room temperature, and filtered through a pad of celite. The celite was washed with DCM (50 mL) and the organic portions were combined. The solution was charged into a bomb hydroginator, then treated with triphenyl phosphite (0.015 ml, 0.048 mmol), ammonium vanadate (44 mg, 0.380 mmol), and platinum (1.853 g, 0.475 mmol). The reaction was sealed and pressurized with hydrogen gas (150 psi) overnight. The reaction was then diluted with DCM (100 mL) and heated to reflux for 1 hr. The hot mixture was filtered through celite, washed with DCM (50 mL), and concentrated to 1.65 g (96%) of the title compound as an off-white solid. [M+H] calc'd for C, 17; H, 22; N, 4; O5, 363; found, 363.

Provenance & Evidence