Water → 3-(2,3,4-Trimethoxybenzoyl)-propiolic acid

Reaktionsgleichung

[CH3:1][O:2][C:3]1[C:16]([O:17][CH3:18])=[C:15]([O:19][CH3:20])[CH:14]=[CH:13][C:4]=1[C:5]([C:7]#[C:8][C:9]([O:11]C)=[O:10])=[O:6].[OH-].[K+].O>O1CCCC1>[CH3:1][O:2][C:3]1[C:16]([O:17][CH3:18])=[C:15]([O:19][CH3:20])[CH:14]=[CH:13][C:4]=1[C:5]([C:7]#[C:8][C:9]([OH:11])=[O:10])=[O:6]

Komponenten

Versuchsvorschrift

A solution of 2.7 g (9.7 mmol) of methyl 3-(2,3,4-trimethoxybenzoyl)propiolate in 30 ml of tetrahydrofuran was treated slowly at 0° with 27 ml of 3% potassium hydroxide solution and subsequently stirred at 0° for a further 1.5 hours. The reaction mixture was treated with water and extracted once with ether. The ether phase was discarded. The aqueous phase was adjusted to pH 1 with 1N hydrochloric acid and extracted twice with ether. The combined organic phases were dried over sodium sulphate and concentrated. Crystallization of the residue from ethyl acetate/hexane yielded 3-(2,3,4-trimethoxybenzoyl)-propiolic acid of melting point 119°-121°.