benzyl 4-(4-{2-[2-(2-fluorophenyl)acetylamino]ethoxy}phenyl)-3-[4-(3-methoxypropyl)-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate → Benzyl 4-(4-{2-[2-(2-fluorophenyl)ethylamino]ethoxy}phenyl)-3-[4-(3-methoxypropyl)-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate

Participants

Reaction Steps

A solution of 0.455 g of benzyl 4-(4-{2-[2-(2-fluorophenyl)acetylamino]ethoxy}phenyl)-3-[4-(3-methoxypropyl)-3,4-dihydro-2H-benz[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate in 5 ml of tetrahydrofuran is admixed at 0° C. with 1.84 ml of diborane-tetrahydrofuran complex (1M solution in tetrahydrofuran). The reaction solution is subsequently heated to reflux over 3 hours. The reaction solution is cooled to room temperature, quenched with 2 ml of methanol and finally admixed with 2 ml of 2M HCl. The mixture is stirred at room temperature over 30 minutes, neutralized with 20 ml of saturated aqueous sodium hydrogencarbonate solution and extracted with 3×20 ml of ethyl acetate. The combined organic phases are washed with 20 ml of brine, dried over sodium sulphate and concentrated by evaporation. The title compound is obtained from the residue by means of flash chromatography (SiO2 60F). Rf=0.52 (200:20:1 dichloromethane-methanol-25% conc. ammonia); Rt=4.83.

Provenance & Evidence