Potassium Hydroxide → 1,1-Dimethylethyl 4-ethenylphenyl carbonate

HRID 2255789Notes

Reaction equation

C(OC1[CH:12]=[CH:11][C:8]([CH:9]=[CH2:10])=[CH:7][CH:6]=1)(=O)C.[OH-].[K+].C(O[C:20]([O:22][C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=[O:24])=O)(C)(C)C>[OH-].[K+].CO>[C:26]([O:25][C:23]([O:22][C:20]1[CH:10]=[CH:9][C:8]([CH:11]=[CH2:12])=[CH:7][CH:6]=1)=[O:24])([CH3:27])([CH3:28])[CH3:29]

Participants

Conditions

Temperature: 12 °C

Procedure

A solution comprising 2.4 g of potassium hydroxide, 201 g 4-acetoxystyrene and 500 g of methanol was heated at reflux for 2.2 hours. The reaction was cooled to 12° C. and 64 g potassium hydroxide pellets were added over a period of 10 minutes. After warming to 25° C., 314 g di-tertiary-butyl-dicarbonate was introduced over a period of one hour. After an additional 2.3 hours of reaction time, the reaction slurry was washed with water and extracted with ethyl acetate. The ethyl acetate was stripped from the extraction mixture using a rotary evaporator, and the residual oil was charged with 0.26 g phenothiazine inhibitor. Distillation at 0.1 mm Hg yielded 227.2 g (85% yield) 4-tertiary-butoxycarbonyloxystyrene (IV).

Workup

temperaturewas heated
temperatureat reflux for 2.2 hours
temperatureAfter warming to 25° C.
customAfter an additional 2.3 hours of reaction time
washthe reaction slurry was washed with water
extractionextracted with ethyl acetate
customa rotary evaporator
additionthe residual oil was charged with 0.26 g phenothiazine
distillationDistillation at 0.1 mm Hg

Sources & evidence

ORD record: ord-c4e2cd4292dd4f5db9a9759778e604fe
Source dataset: uspto-grants-1993_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05241098

Reaction notes

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