meso-2,5-Dibromo-hexanedioic acid diethyl ester JS-053: Adipic acid (795 g, 3.93 mol) was added in small portions to thionylchloride (980 mL, 5.44 mol) for 2 hours at 65 degC. This suspension was mechanically stirred and heated on an oil bath for an additional 3.5 hours at 70 degC, until the gas evolution was finished. To the UV lamp irradiated (2x 120W) solution was added dropwise bromine (664 mL, 12.48 mol) for 7 hours at 85-95 degC. After finishing of absorption of bromine, the reaction mixture was cooled down, poured into ethanol (4000 mL, 96 %) at -5 degC and mechanically stirred for an additional 1 week at rt. Crystals were filtered off and washed with ethanol (2x 300 mL, 96 %) to afford meso-2,5-dibromo-hexanedioic acid diethyl ester (JS-053, 1343 g, 3.73 mol, yield 95 %, GC 98 %, mp 66 degC/lit.
