Yield:54109-14-7 91.7%

Reaction Conditions:

with sodium hydroxide;bromine in chloroform;

Steps:

28.i i

i α-Bromo-2,3,4-trimethoxyacetophenone 25 g of 2,3,4-trimethoxyacetophenone, 600 ml of ether and 240 ml of chloroform were mixed. To the resulting mixture was dropwise added under chilling with ice/sodium chloride mixture a solution of 19.18 g of bromine in 120 ml of chloroform for 3.3 hours. The resulting solution was washed successively with chilled water, chilled 5% aqueous sodium hydroxide solution, chilled water and aqueous sodium chloride solution, and dried over anhydrous sodium sulfate. Thereafter, the solvent was distilled off under reduced pressure at a temperature of lower than 50° C., leaving 33.0 g of yellow oil, yield 91.7%. ¹ H-NMR (CDCl₃) δ:3.86 (s, 3H), 3.92 (s, 3H), 4.05 (s, 3H), 4.56 (s, 2H), 6.73 (d, 1H, J=9 Hz), 7.60 (d, 1H, J=9 Hz). IR (neat) cm^-1: 2950, 1680, 1490, 1410, 1290, 1210, 1110, 1000, 810.

References:

US5070089,1991,A