Methanol → methyl (E)-beta-methoxy-2-methylcinnamate
Reaktionsgleichung
[CH:1]([O:6]C)([O:4][CH3:5])OC.[CH3:8][OH:9].OS(O)(=O)=O.N1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>>[CH3:8][O:9]/[C:17](/[C:18]1[CH:19]=[CH:18][CH:17]=[CH:16][C:19]=1[CH3:20])=[CH:16]/[C:1]([O:4][CH3:5])=[O:6]Komponenten
5
Versuchsvorschrift
A mixture of 1280 g (6.7 mol) of methyl 2-methylbenzoyl acetate, 848 g (8.0 mol) of trimethyl orthoformate, 400 ml of methanol and 10 ml of concentrated H2SO4 is stirred at room temperature for 12 h. The mixture is subsequently neutralized with 20 ml of pyridine and then concentrated, and the residue is fractionally distilled (boiling point 120°-123° C./0.6 torr). 1300 g (94%) of methyl (E)-β-methoxy-2-methylcinnamate are obtained as a pale yellow oil.