To a stirred solution of 28.4 parts of 1H-1,2,4-triazole in 135 parts of N,N-
dimethylformamide were added 11.4 parts of a sodium hydride dispersion
80% under nitrogen atmosphere. After stirring for 1 hour at room
temperature, a solution of 40 parts of 6-[chloro(4-chlorophenyl)-methyl]-1-
methyl-1H-benzotriazole in 90 parts of N,N-dimethylformamide was added to
the mixture. The whole was stirred for 1 hour at 60°C. The reaction mixture
was diluted with 50 parts of water and the whole was evaporated. The residue
was extracted with ethyl acetate. The extract was washed with water, dried,
filtered and evaporated. The residue was purified by column chromatography
over silica gel using a mixture of dichloromethane and methanol (99:1 by
volume) as eluent. The pure fractions were collected and the eluent was
evaporated. The residue was crystallized from a mixture of 2-propanone and
1,1'-oxy-bis-ethane (ether). The product was filtered off and dried, yielding 13
parts (29.2%) of 6-[(4-chlorophenyl)-(1H-1,2,4-triazol-1-yl)methyl]-1-methyl-
1H-benzotriazole; MP: 178.9°C. A resolution of enantiomers any usual method
gave crystals from 2-propanol, MP: 130-135°C. [α] D 20 = 8.0° (plus or minus)
(c = 10 in CH 3 OH).
