Potassium Hydroxide → 2,4-Bis(benzyloxy)-5-isopropenylbenzoic acid

HRID 334982Notes

Reaction equation

[OH-].[K+].[CH2:3]([O:10][C:11]1[CH:20]=[C:19]([O:21][CH2:22][C:23]2[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=2)[C:18]([C:29]([CH3:31])=[CH2:30])=[CH:17][C:12]=1[C:13]([O:15]C)=[O:14])[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1>CO.O>[CH2:3]([O:10][C:11]1[CH:20]=[C:19]([O:21][CH2:22][C:23]2[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=2)[C:18]([C:29]([CH3:31])=[CH2:30])=[CH:17][C:12]=1[C:13]([OH:15])=[O:14])[C:4]1[CH:5]=[CH:6][CH:7]=[CH:8][CH:9]=1

Participants

Conditions

Temperature: 40 °C

Procedure

Potassium hydroxide (0.527 Kg, 9.4 mol) was added to a stirred suspension of methyl 2,4-bis-benzyloxy-5-isopropenyl-benzoate (3.1 Kg, 8 mol, step 4) in methanol (18.6 L) and water (12.4 L) and the mixture was stirred and held at reflux for 3 hours. The methanol was removed under partial vacuum from the vessel, and to the remaining solution was added toluene (62 L). The solution was heated to 40° C. and to the mixture was added conc HCl (1.36 L). The biphasic mixture is heated to 50° C. and the phases separated. The organic phase was washed with water (31 L) at 50° C. and the organic phase was evaporated under redeuced pressure to give 2,4-bis-benzyloxy-5-isopropenyl-benzoic acid 2.851 Kg (95% yield) as a colourless solid.

Workup

temperatureat reflux for 3 hours
customThe methanol was removed under partial vacuum from the vessel
additionto the remaining solution was added toluene (62 L)
additionwas added conc HCl (1.36 L)
temperatureThe biphasic mixture is heated to 50° C.
customthe phases separated
washThe organic phase was washed with water (31 L) at 50° C.
customthe organic phase was evaporated under redeuced pressure

Sources & evidence

ORD record: ord-066fb53311574e8e8cd90d073216264e
Source dataset: uspto-grants-2014_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08883790B2

Reaction notes

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