Реакция #640169

Уравнение реакции

NaHCO3

Boron tribromide

benzisoxazole

( c )

3-ethoxy-6-methoxy-1,2-benzisoxazole

NaCl

→

3-ethoxy-6-hydroxy-1,2-benzisoxazole

Растворители

water

hexane ethyl acetate

dichloromethane

Условия реакции

Обработка

1. 1
   ЭкстракцияThe aqueous phase was extracted into dichloromethane (3×60 ml)
2. 2
   Промывкаwashed with brine (10 ml)
3. 3
   Сушкаdried (NaSO4)
4. 4
   ДругоеThe product was purified by chromatography on silica (18 g
5. 5
   ПромывкаThe first compound to elute

Методика

Boron tribromide (1.0M solution in dichloromethane; 1.39 ml, 1.39 mmol) was added to a stirred, −78° cooled solution of benzisoxazole from part (c) (179 mg, 928 μmol) in dichloromethane (4 ml) under an argon atmosphere. The reaction mixture was gradually warmed to room temperature over approx. 2 hours, and stirred overnight. Tlc (silica, 2:1 hexane/ethyl acetate) showed new polar material as well as unreacted starting material. The reaction was worked up by adding water (5 ml) and ice. The aqueous phase was neutralized by addition of saturated NaHCO3 solution, and saturated with NaCl. The aqueous phase was extracted into dichloromethane (3×60 ml), then the organic extracts combined and washed with brine (10 ml) and dried (NaSO4). The product was purified by chromatography on silica (18 g; eluent 2.5%, 5%, then 15% ethyl acetate/hexane). The first compound to elute was unreacted 3-ethoxy-6-methoxy-1,2-benzisoxazole, (46 mg), followed by 3-ethoxy-6-hydroxy-1,2-benzisoxazole 108 mg (65%).

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