Synthesis and anticancer effects evaluation of 1-alkyl-3-(6-(2-methoxy-3-sulfonylaminopyridin-5-yl)benzo[d]thiazol-2-yl)urea as anticancer agents with low toxicity.

As a PI3K and mTOR dual inhibitor, N-(2-chloro-5-(2-acetylaminobenzo[d]thiazol-6-yl)pyridin-3-yl)-4-fluorophenylsulfonamide displays toxicity when orally administrated. In the present study, alkylurea moiety replaced the acetamide group in the compound and a series of 1-alkyl-3-(6-(2,3-disubstituted pyridin-5-yl)benzo[d]thiazol-2-yl)urea derivatives were synthesized. The antiproliferative activities of the synthesized compounds in vitro were evaluated against HCT116, MCF-7, U87 MG and A549 cell lines. The compounds with potent antiproliferative activity were tested for their acute oral toxicity and inhibitory activity against PI3Ks and mTORC1. The results indicate that the compound attached a 2-(dialkylamino)ethylurea moiety at the 2-positeion of benzothiazole can retain the antiproliferative activity and inhibitory activity against PI3K and mTOR. In addition, their acute oral toxicity reduced dramatically. Moreover, compound 2f can effectively inhibit tumor growth in a mice S180 homograft model. These findings suggest that 1-(2-dialkylaminoethyl)-3-(6-(2-methoxy-3-sulfonylaminopyridin-5-yl)benzo[d]thiazol-2-yl)urea derivatives can serve as potent PI3K inhibitors and anticancer agents with low toxicity.