Sodium Chloride → alpha-(p-Bromophenyl)-alpha-phenyl-1-(toluene-p-sulphonyl)imidazole-2-methanol

Beteiligte Stoffe

Reaktionsschritte

To a solution of 33.3 g. (0.15 mol) of 1-(toluene-p-sulphonyl)imidazole (H. A. Staab and K. Wendel, Ber. 93, (1960) 2902) in 300 ml. of anhydrous tetrahydrofuran and 150 ml. of anhydrous diethyl ether at a temperature of -40° to -50° C. under a nitrogen atmosphere were added drop-wise 91 ml. of a 20% solution of butyllithium in n-hexane (0.20 mol.) dissolved in 150 ml. of anhydrous diethyl ether. Upon completion of the addition, the mixture was kept at a temperature of -40° to -50° C. for one hour. Next and under identical conditions as to temperature 44.4 g. (0.17 mol) of 4-bromobenzophenone in 200 ml. of anhydrous tetrahydrofuran and 100 ml. of anhydrous diethyl ether were added drop-wise and the mixture was kept under the same conditions for another 3.5 hours. Cooling was stopped and the mixture was allowed to reach ambient temperature in 1/2 hour. It was then poured out into about 250 ml. of a sodium chloride solution. The aqueous layer was separated and discarded, the organic solvents layer was washed with 100 ml. of a sodium chloride solution, dried and concentrated. The residual oil was brought to crystallisation by addition of a very small amount of diethyl ether. Purification was brought about by crystallisation from warm ethanol to which some acetone was added. Melting point of the product was 138°-140° C.

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