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

HRID 1486497Notes

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 cone 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 reduced 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 cone 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 reduced pressure

Sources & evidence

ORD record: ord-e339a2c0dbda4689bfa86dcafd510488
Source dataset: uspto-grants-2016_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09428439B2

Reaction notes

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