3-(4-Hydroxy-3-Methoxyphenyl)Prop-2-Enoic Acid → 3-(4-Hydroxy-3-methoxyphenyl)-2-propenoic acid 4-bromobutyl ester
Reaktionsgleichung
[OH:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]=[CH:9][C:10]([OH:12])=[O:11])=[CH:4][C:3]=1[O:13][CH3:14].[CH2:15]1[CH2:19]O[CH2:17][CH2:16]1.C(Br)(Br)(Br)[Br:21]>>[Br:21][CH2:17][CH2:16][CH2:15][CH2:19][O:11][C:10](=[O:12])[CH:9]=[CH:8][C:5]1[CH:6]=[CH:7][C:2]([OH:1])=[C:3]([O:13][CH3:14])[CH:4]=1Komponenten
4
Versuchsvorschrift
To a solution of 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid (10 g, 51.5 mmoles) in THF (400 ml) triphenylphosphine (2.7 g, 10.3 mmoles) and carbon tetrabromide (34.16 g, 10.3 mmoles) are added and the solution is left at room temperature, under magnetic stirring, for 48 hours. The solid is filtered and then evaporated at reduced pressure. The obtained crude product is purified by chromatogrphy on silica gel eluting with n-hexane/ethyl acetate 7/3. 9 g of 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid 4-bromobutyl ester are obtained. M.p.=86–89° C.