N-bromobutanimide → HCID 86701110, compound

Participants

Reaction Steps

A mixture of tert-butyl (3aR,5R,6S,7R,7aR)-6,7-bis(benzyloxy)-5-(hydroxymethyl)-5,6,7,7a-tetrahydro-3aH-pyrano[3,2-d]thiazol-2-yl(2-fluoroethyl)carbamate (600 mg, 1.10 mmol), KHCO3 (495 mg, 4.95 mmol), TBAB (18 mg, 0.06 mmol) and TEMPO (9 mg, 0.06 mmol) in dichloromethane (17 mL) and water (2 mL) was treated with NBS (215 mg, 1.21 mmol) for 15 min at 10-15° C. The reaction mixture was quenched by saturated aqueous Na2SO3 (5 mL), extracted with dichloromethane (3×15 mL), dried over magnesium sulfate, and concentrated under vacuum to give a residue, which was purified by a silica gel column, eluting with 20% ethyl acetate in petroleum ether to provide compound 72 as a yellow syrup (0.4 g, 67%). (ES, m/z) [M+H]+ 545.0; 1H NMR (300 MHz, CDCl3) δ 9.64 (s, 1H), 7.23-7.39 (m, 10H), 6.09-6.11 (d, J=6.3 Hz, 1H), 4.55-4.75 (m, 5H), 4.34-4.45 (m, 2H), 4.13-4.28 (m, 3H), 3.90-4.12 (m, 2H), 1.54 (s, 9H).

Provenance & Evidence