Abstract: A method for preparing a cephalosporin compound represented by the general formula (III) ##STR1## (wherein R represents hydrogen or methyl group) or a pharmaceutically acceptable salt thereof, which is characterized by reacting 7-amino-3-(benzimidazol-2-yl)-thiomethyl-3-cephem-4-carboxylic acid represented by the general formula (I) ##STR2## or a salt thereof with a compound represented by general formula (II) ##STR3## wherein R represents hydrogen or methyl group.

Abstract: A process for the production of 2-aryl-2H-benzotriazoles comprises reducing and cyclizing the corresponding o-nitroazobenzenes with hydrogen at a temperature in the range of about 20.degree. C. to about 100.degree. C. and at a pressure in the range of about 15 psia (1 atmosphere) to about 1000 psia (66 atmospheres) in an alkaline medium at a pH over 10 in the presence of a nickel catalyst, preferably molybdenum-promoted Raney nickel. High yields of pure product are obtained directly with a concomitant reduction of undesired by-product and a reduction in effluent pollution problems.