Sodium Hydroxide → Benzyl 4-{4-[2-(cyclohexylmethylamino)ethoxy]phenyl}-3-[4-(3-methoxypropyl)-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate

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Reaction Steps

A solution of 0.346 g of benzyl 4-[4-(2-aminoethoxy)phenyl]-3-[4-(3-methoxypropyl)-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate (Example 184b) and 0.068 ml of cyclohexanecarbaldehyde in 2 ml of methanol is stirred at room temperature over 3.5 hours, admixed in portions with 0.037 g of sodium borohydride and subsequently stirred for a further 2 hours. The reaction mixture is admixed with 2 ml of 1N NaOH, stirred for 30 minutes and then partitioned between ethyl acetate and water. The organic phase is washed with brine, dried over sodium sulphate and concentrated by evaporation. The title compound is obtained as a yellow oil from the residue by means of flash chromatography (SiO2 60F). Rf=0.48 (200:20:1 dichloromethane-methanol-25% conc. ammonia); Rt=4.97.

Provenance & Evidence