反应详情

1,1-Dimethylethyl 4-(6-fluoro-5-methyl-2-oxo-1,3-benzoxazol-3(2H)-yl)-1-piperidine carboxylate (D2, 546 mg, 1.14 mmol) was dissolved in dichloromethane (10 mL) at rt. HCl (10 mL, 40 mmol, 4 M in 1,4-dioxane) was added and the reaction was stirred overnight. It was then concentrated by rotary evaporation to give a pale brown solid. The residue was dissolved in methanol/dichloromethane and purified by SCX (5 g, eluting with methanol, followed by 2 M ammonia in methanol). The ammonia/methanol fraction was concentrated by rotary evaporation to give 6-fluoro-5-methyl-3-(4-piperidinyl)-1,3-benzoxazol-2(3H)-one (D3, 318 mg, 72% purity, 80% yield) as an orange oil.

1. concentrationIt was then concentrated by rotary evaporation
2. customto give a pale brown solid
3. custompurified by SCX (5 g, eluting with methanol, followed by 2 M ammonia in methanol)
4. concentrationThe ammonia/methanol fraction was concentrated by rotary evaporation