| abstract |
A process for the preparation of anthelmintic compounds of the formula: <IMAGE> wherein R1 is hydrogen or -COOR; R5 is C1 to C4 alkyl; R2 is halogen, alkyl, trifluoromethyl, alkoxy, aryloxy, or aralkoxy; and R4 is hydrogen, alkyl, cycloalkyl; alkenyl, alkynyl or aralkyl; or pharmaceutically acceptable salts thereof comprises subjecting a bis compound of the formula: <IMAGE> to reduction to cleave the disulfide linkage and where R4 is other then hydrogen, subsequent reaction of the mercapto group. Intermediate compounds and a process for preparing same are also disclosed. |