Hydrochloric Acid → (R)-3-cyclohexyl-2,3-dihydropyrrolo[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid

Participants

Reaction Steps

To a solution of (R)-3-cyclohexyl-6-trifluoromethylcarbonyl-2,3-dihydropyrrolo[1,2,3-de]-1,4-benzoxazine (628 mg, 1.86 mmol) in 1,4-dioxane (20 ml) was added 4 N NaOH (5.0 ml). The mixture was refluxed for 42 h, then acidified to pH 1 using 5 N hydrochloric acid and partitioned between dichloromethane and water. The aqueous layer was extracted with dichloromethane, and combined organic layers were washed with brine, dried over Na2SO4 and concentrated to afford (R)-3-cyclohexyl-2,3-dihydropyrrolo[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (572 mg). The title compound was prepared following the method of Example 7, using (R)-3-cyclohexyl-2,3-dihydropyrrolo[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid amide (prepared from (R)-3-cyclohexyl-2,3-dihydropyrrolo[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid) instead of 1-(cyclohexyl)methyl-7-methoxy-1H-indole-3-carboxylic acid amide. EsIMS: m/z 411.0 [M+H]+; [α]D22−30.7° (c=1.50 mg/ml in chloroform)

Provenance & Evidence