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New [(Indolyl)pyrazolyl]-1,3,4-oxadiazole compounds and their derived thioglycosides as well as the corresponding sugar hydrazones were synthesized. The acyclo C-nucleoside analogs of the oxadiazoline base system were also prepared by reaction of acid hydrazides with aldehydo sugars followed by one pot process encompassing acetylation and cyclization of the synthesized hydrazones. The anticancer activity of the newly synthesized compounds was studied against colorectal carcinoma (HCT116), breast adenocarcinoma (MCF7) and prostate cancer (PC3) human tumor cell lines and a number of compounds showed moderate to high activities.

Reactions of 3,S-diaminopyrazoles with chalcones and ethyl a-ncetylcinnamates lead to new polyfunctional derivatives of pyrazolo[ 1JuIpyrimidine.The structures of the products and the mechanisms of their formation are Pyrazolopyrimidines are purine analogues and as such they have useful properties as antimetabolites in purine biochemical reactions"). Moreover, these compounds have marked antitumor and antileukemic activity3'. In previous work we have reported a variety of new procedures for the. preparation of differently substituted pyrazolo[l,5-u]pyrimidine derivatives4'.In this paper, the behaviour of 4-arylazo-3,5-pyrazolediamines 1 towards the action of a variety of a,bunsatumred reagents was investigated: la-d react with chalcones 2a-g in ethanol containing catalytic amounts of piperidine to afford the 2-amino-3-arylazo-5,7-diaryl-pyrazolo[ 1,5-a]pyrimidines 5a-z in good yield. The formation of 5 from the reaction of 1 with 2 is assumed to proceed by a Michael type addition of the most basic ring-N in 1 to the activated double bond in 2. The intermediatly formed Michael adducts 3 cycliz by water elimination to give the dihydropyrazolopyrimidines 4 which aromatize to yield the end products 5. -Although one may argue that the reaction of 1 with chalcones 2 may involve exocyclic or endocyclic pyrazole-N, involvement of endocyclic pyrazole-N leading to 5 was assumed based on the ability of pyrazoles to be alkylated at the ring-N5) and in analogy to previous lit.@.

New substituted pyrazole, thiazole, and 1,2,4‐triazole derivatives were synthesized. The sugar hydrazones, their acetylated derivatives as well as their derived acyclic C‐nucleoside analogs, and the thioglycosides of the 1,2,4‐traizole derivatives were also prepared. The antitumor activity of some of the synthesized compounds were studied, and a number of the tested compounds showed significant activities.