Quest for anthelmintic agents. Part I. Para substituted phenylisothiocyanates, heterocyclylisothicyanates and bisisothiocyanates

Abstract

A number of p-substituted phenylisothiocyanates 4a-4r, heterocyclylisothiocyanates 6a-6f and bisisothiocyanates 7a-7e were synthesised as analouges of the active anthelmintic agents, bitoscanate 1 and amoscanate 2. From among these, some benzazolyl phenylisothiocyanates 4k, 4n 4o and 4p and two benzinidazolyl methyloxy phenylisothiocyanates 4q and 4r were converted into adducts (8a-8h, 9a-9d) of N-methylpiperazine and N,N-diethylcarbamoylpiperazine. Amoscanate 2 was condensed with aminoacids and histamine to afford products 10a-10h. These isothiocyanates and adducts were tested for antihookworm activity in the N. americanus infested hamster. Fairly good activity was exhibited by 4-(4-chlorophenyl mercapto) phenylisothiocyanate 4f, 4-(2-methyl-4-thiazolyl) phenylisothiocyanate 4i, 4-(2-benzthiazolyl) phenylisothiocyanate 4k, 4-(2-benzimidazolyl) phenylisothiocyanate 4n, among which 4k was the most active.