4,4'-Dichlorobenzophenone → Bis-(4-chloro-phenyl)-isothiazol-5-yl-methanol

Beteiligte Stoffe

Reaktionsschritte

To a solution of 1.0 g of isothiazole in 20 ml of tetrahydrofuran were added 8.1 ml of a 1.52M solution of n-butyllithium in hexane at -78° C. The mixture was allowed to stir for 15 minutes at which time 3.2 g of 4,4'-dichlorobenzophenone were added as a solution in 25 ml of tetrahydrofuran. The reaction was allowed to warm to room temperature and was stirred for 2 hours. Twenty-five milliliters of a saturated ammonium chloride solution were added and the tetrahydrofuran was removed by evaporation. The resulting mixture was extracted three times with ethyl acetate. The combined organic extracts were washed with a saturated ammonium chloride solution, water, and a saturated sodium chloride solution, dried over magnesium sulfate and evaporated. The resulting oil was chromatographed over silica gel. The appropriate fractions were combined and evaporated resulting in an oil. Cyclohexane was added and 1.21 g of the desired title product were recovered by filtration as white crystals, m.p. 118°-119.5° C.

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