Lithium hydroxide, monohydrate → (RS)-4-[2-(4,4-dimethyl-thiochroman-6-yl)-heptyloxy]-benzoic acid

HRID 394949Notes

Reaction equation

[CH3:1][C:2]1([CH3:30])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH:12]([CH2:25][CH2:26][CH2:27][CH2:28][CH3:29])[CH2:13][O:14][C:15]3[CH:24]=[CH:23][C:18]([C:19]([O:21]C)=[O:20])=[CH:17][CH:16]=3)[CH:10]=2)[S:5][CH2:4][CH2:3]1.O.[OH-].[Li+]>C1COCC1.O.CCOCC>[CH3:1][C:2]1([CH3:30])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH:12]([CH2:25][CH2:26][CH2:27][CH2:28][CH3:29])[CH2:13][O:14][C:15]3[CH:16]=[CH:17][C:18]([C:19]([OH:21])=[O:20])=[CH:23][CH:24]=3)[CH:10]=2)[S:5][CH2:4][CH2:3]1

Participants

Conditions

Temperature: 40 °C

Procedure

140 mg of (RS)-methyl 4-[2-(4,4-dimethyl-thiochroman-6-yl)-heptyloxy]-benzoate, dissolved in 20 ml THF/5 ml H2O/5 ml methanol, was treated with 200 mg of lithium hydroxide hydrate. The mixture was stirred at 40° C. for 6 hours. The mixture was diluted with 5 ml water and acidified to pH 2 with 1N hydrochloric. The resulting suspension was taken in 20 ml ether and the phases were separated. The aqueous phase was extracted with three portions of 10 ml ether. The combined extracts were dried over MgSO4. The solvent was removed in vacuo and the crude product was purified by flash chromatography (10% methanol/methylene chloride), yielding a colorless oil. Trituration in hexanes provided a white solid, m.p. 168-169° C.

Workup

customthe phases were separated
extractionThe aqueous phase was extracted with three portions of 10 ml ether
dry with materialThe combined extracts were dried over MgSO4
customThe solvent was removed in vacuo
customthe crude product was purified by flash chromatography (10% methanol/methylene chloride)
customyielding a colorless oil

Sources & evidence

ORD record: ord-11a37247b5c7478db5c5e030f861be51
Source dataset: uspto-grants-2003_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06603012B2

Reaction notes

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