Methanol → HCID 86727499, compound

Participants

Reaction Steps

To a solution of 3-methyl-3-[(R)-1-((R)-4-methyl-3-oxo-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-yl)-ethyl]-azetidine-1-carboxylic acid tert-butyl ester (diastereomer 1, 0.283 g, 0.683 mmol) in AcOH (1 mL) was added a solution of bromine (0.070 mL, 1.366 mmol) in AcOH (1 mL) drop-wise and the reaction mixture was stirred for 1 h at ambient temperature. The reaction mixture was quenched by the addition of saturated aqueous NaS2O3 solution and aqueous NaHCO3 solution to pH 7-8. MeOH (5 mL), TEA (0.146 g, 1.439 mmol) and di-tert-butyl dicarbonate (0.188 g, 0.864 mmol) were added in sequence to the above mixture and the reaction mixture was stirred at ambient temperature for 1.5 h. The aqueous solution was extracted with EtOAc (3×10 mL) and the combined organic phase was washed with saturated brine (10 mL), dried over Na2SO4 and filtered. The filtrate was evaporated to dryness and the residue was purified by prep-TLC (eluting with 50% EtOAc in petroleum ether) to give 3-[(R)-1-((R)-7-bromo-4-methyl-3-oxo-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-yl)-ethyl]-3-methyl-azetidine-1-carboxylic acid tert-butyl ester (0.128 g, 36%) as a solid. LC/MS (Table 1, Method 25) Rt=0.913 min.; MS m/z: 437 [M+H−56]+ and 439 [M+H−56]+. 1H NMR (CDCl3, 400 MHz): δ 8.26 (brs, 1H), 7.25 (s, 1H), 6.70 (s, 1H), 4.75-4.70 (m, 1H), 4.60 (d, J=12.8 Hz, 2H), 3.98-3.91 (m, 2H), 3.55 (m, 2H), 3.44 (d, J=8.4 Hz, 1H), 1.52 (d, J=6.8 Hz, 3H), 1.46 (s, 9H), 1.32-1.27 (m, 6H).

Provenance & Evidence