O[N:2]1[C:6]2[CH:7]=[C:8]([CH:11]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[OH:12])[CH:9]=[CH:10][C:5]=2[N:4]=[N:3]1.[H-].[Na+].[H][H].BrCC(OCC)=O.C(=O)([O-])[O-].[K+].[K+]>CS(C)=O>[C:13]1([CH:11]([C:8]2[CH:9]=[CH:10][C:5]3[NH:4][N:3]=[N:2][C:6]=3[CH:7]=2)[OH:12])[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1To a stirred solution of 5.2 parts of 1-hydroxy-α-phenyl-1H-benzotriazole-6-methanol in 30 parts of dimethyl sulfoxide were added 0.96 parts of a sodium hydride dispersion 50%. The reaction mixture was stirred till no more hydrogen escapted. After the addition of 3.34 parts of ethyl 2-bromoacetate, the whole was stirred for 30 minutes at room temperature. 1.38 Parts of potassium carbonate were added and stirring was continued for 3 hours at 50° C. The dimethyl sulfoxide layer was evaporated and the residue was taken up in water and 20 parts of a hydrochloric acid solution 1N. The product was extracted with a mixture of trichloromethane and methanol (90:10 by volume). The extract was dried, filtered and concentrated. The concentrate was crystallized from 32.5 parts of dichloromethane. The product was filtered off and dried, yielding 3.1 parts (68.8%) of α-phenyl-1H-benzotriazole-5-methanol; mp. 143.0° C. (int. 70).
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