Hydrochloric Acid → 7-[2-(Cyclopropylmethoxy)-6-hydroxyphenyl]-1,4-dihydro-5-[(3S)-3-piperidinyl]-2H-pyrido[2,3-d][1,3]oxazin-2-one hydrochloride

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Reaction Steps

To a solution of tert-butyl (3S)-(−)-3-(7-{2-(cyclopropylmethoxy)-6-[(4-methoxy-benzyl)oxy]phenyl}-2-oxo-1,4-dihydro-2H-pyrido[2,3-d][1,3]oxazin-5-yl)-1-piperidinecarboxylate (1.0 g, 1.624 mmol) in dioxane (15 mL) was added 4N HCl in dioxane (30 mL) at room temperature. The stirring was continued for 3 hrs. After the solvent was removed by evaporation, the resulting solid was triturated with acetonitril, collected by filtration, and washed with acetonitrile. The solid was recrystallized from methanol to give (−)-7-[2-(cyclopropylmethoxy)-6-hydroxy-phenyl]-5-[(3S)-3-piperidinyl]-1,4-dihydro-2H-pyrido[2,3-d][1,3]oxazin-2-one hydrochloride as a white solid (0.502 g, yield; 71%). The absolute configuration for the chiral atom was determined with (S) by the X-ray analysis.

Provenance & Evidence