Methanol → HCID 20086967、化合物

2.69 g (4.88 mmoles) of the compound of Example 44 are dissolved in 53 ml of anhydrous benzene. 2.92 ml of boron tribromide are dropped to the solution so that the temperature of the reaction mixture should not exceed 20° C. The suspension thus obtained is stirred at room temperature for half an hour. Then 40 ml of methanol are dropped under stirring and cooling with icy water at such a rate that the inner temperature should not exceed 25° C. The reaction mixture is evaporated, the residue is boiled with 68 ml of distilled water for 1 hour, the solution is cooled, diluted with 100 ml of distilled water, the pH is adjusted with solid potassium hydrogen carbonate to neutral and the solution is extracted with chloroform. The organic phase is dried and evaporated, then the residue is purified by column chromatography. Thus 1.01 g (48%) of the desired compound are obtained. Rf =0.45. Its monohydrochloride salt melts at 181°-183° C.