Ethanolamine → Benzyl 4-(4-{[2-(2,5-difluorophenoxy)ethylamino]methyl}phenyl)-3-[4-(3-methoxypropyl)-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate

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Reaction Steps

The solution of 0.440 g of benzyl 4-{4-[2-(2,5-difluorophenoxy)ethylcarbamoyl]phenyl}-3-[4-(3-methoxypropyl)-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate in 2.0 ml of tetrahydrofuran is admixed with 13.6 ml of 9-BBN (0.5M in tetrahydrofuran) and stirred at reflux over 18 hours. The reaction mixture is cooled, admixed with 0.412 ml of ethanolamine and concentrated by evaporation. The residue is stirred at 0° C. in 40 ml of EtOAc-heptane (1:1) overnight and clarified by filtration, and the filtrate is concentrated by evaporation. The title compound is obtained as a slightly yellowish oil from the residue by means of flash chromatography (SiO2 60F). Rf=0.11 (1:3 EtOAc-heptane); Rt=4.76.

Provenance & Evidence