Boron tribromide → 2-(4-Hydroxyphenyl)-2-methylpropanenitrile

HRID 130708

Reaction equation

C[O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]([CH3:13])([CH3:12])[C:10]#[N:11])=[CH:5][CH:4]=1.B(Br)(Br)Br>ClCCl>[OH:2][C:3]1[CH:4]=[CH:5][C:6]([C:9]([CH3:13])([CH3:12])[C:10]#[N:11])=[CH:7][CH:8]=1

Participants

Conditions

Temperature: -78 °C

Procedure

Add anhydrous dichloromethane (400 mL) to 2-(4-methoxy-phenyl)-2-methyl-propionitrile (11.93 g, 68.1 mmol) and cool to −78° C. under nitrogen. Then add boron tribromide (33.0 mL, 349 mmol) and stir at −78° C. for 30 minutes. Remove the dry ice/acetone bath and allow the reaction to warm to room temperature. Stir for 3 h and then pour the reaction onto ice. Extract with ethyl acetate (2×150 mL), dry the extracts over magnesium sulfate, filter, and concentrate on a rotary evaporator to give the crude product. The crude product is purified by flash chromatography on silica gel eluting with 35% ethyl acetate/hexanes to yield 9.79 g (89%) of 2-(4-hydroxy-phenyl)-2-methyl-propionitrile: TLC: Rf in 40% ethyl acetate/hexanes: 0.38; 1H NMR (CDCl3): 7.34-7.32 (m, 2H), 6.86-6.83 (m, 2H), 5.23 (s, 1H), 1.70 (s, 6H).

Workup

customRemove the dry ice/acetone bath
customthe reaction
temperatureto warm to room temperature
additionpour
customthe reaction onto ice
extractionExtract with ethyl acetate (2×150 mL)
dry with materialdry the extracts over magnesium sulfate
filtrationfilter
concentrationconcentrate on a rotary evaporator
customto give the crude product
customThe crude product is purified by flash chromatography on silica gel eluting with 35% ethyl acetate/hexanes

Sources & evidence

ORD record: ord-17403e7d64164441a006a5b2b4c2c38c
Source dataset: uspto-grants-2008_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07381719B2

Linked notes

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