Potassium Hydroxide → (E)-p-(2-(4,4-Dimethylchroman-6-yl)propenyl)benzoic acid

HRID 1382903Notes

Reaction equation

[CH3:1][C:2]1([CH3:25])[C:11]2[C:6](=[CH:7][CH:8]=[C:9](/[C:12](/[CH3:24])=[CH:13]/[C:14]3[CH:23]=[CH:22][C:17]([C:18]([O:20]C)=[O:19])=[CH:16][CH:15]=3)[CH:10]=2)[O:5][CH2:4][CH2:3]1.[OH-].[K+]>C(O)C>[CH3:1][C:2]1([CH3:25])[C:11]2[C:6](=[CH:7][CH:8]=[C:9](/[C:12](/[CH3:24])=[CH:13]/[C:14]3[CH:15]=[CH:16][C:17]([C:18]([OH:20])=[O:19])=[CH:22][CH:23]=3)[CH:10]=2)[O:5][CH2:4][CH2:3]1

Participants

Conditions

Temperature: 60 °C

Procedure

Under a nitrogen atmosphere, a suspension of 10.9 g (32.4 mmol) of methyl 4-[(E)-2-(4,4-dimethyl-6-chromanyl)-2-methylvinyl]benzoate in 100 ml of ethanol was treated by dropwise addition of 100 ml of 6N potassium hydroxide, with stirring at 60° C. After 1 hour a clear solution resulted. The ethanol was removed by evaporation under reduced pressure, and 100 ml of water was added. The resulting mixture was acidified with 125 ml of concentrated hydrochloric acid, and the acidified mixture was extracted with dichloromethane. The combined extracts were dried (MgSO4) and evaporated in vacuo to give 10.4 g (99% yield) of a solid. Recrystallization of 8.4 g of this solid yielded 5.6 g of the title compound, mp 179°-181° C.

Workup

customAfter 1 hour a clear solution resulted
customThe ethanol was removed by evaporation under reduced pressure, and 100 ml of water
additionwas added
extractionthe acidified mixture was extracted with dichloromethane
dry with materialThe combined extracts were dried (MgSO4)
customevaporated in vacuo

Sources & evidence

ORD record: ord-41a73fe6478b4036b08c1e5b6faadff7
Source dataset: uspto-grants-1989_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04808597

Reaction notes

Loading…