Compounds useful as antiproliferative agents

Abstract

Melatonin compounds are disclosed of the formula ##STR1## where R is hydrogen or C.sub.1 to C.sub.6 linear or branched alkylene substituted with phenyl; R.sub.1 is hydrogen, substituted benzyl, naphthylmethyl or taken together with R.sub.2 and the two carbon atoms of the five-membered hetero ring form the group ##STR2## where R.sub.1 ' is C.sub.1 to C.sub.6 linear or branched alkanoyl and R.sub.1 ' is hydrogen, C.sub.1 to C.sub.6 linear or branched alkyl or phenyl optionally substituted with one or more halogen, amino, nitro, hydroxy, alkyl, alkoxy or haloalkyl; R.sub.2 is hydrogen, 1-pyrrolyl, 1-pyrrolyl substituted with one or more alkyl or alkoxy, the group --(CH.sub.2).sub.m --NHR.sub.2 '1, where m is 1 to 3 and R.sub.2 ' is phenyl sulfonyl, the phenyl group optionally substituted with alkyl, or --C(O)--R.sub.2 ', where R.sub.2 ' is C.sub.1 to C.sub.6 linear or branched alkylene substituted with a substituent selected from the group consisting of hydrogen, phenyl, alkoxy, alkoxy substituted with phenyl, carboxylic acid or the alkyl esters thereof, carbamoyloxy alkyl, substituted carbamoyloxy alkyl and amino or 5-(2-alkanoyl) tetrazole; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are the same or different and are hydrogen, C.sub.1 to C.sub.6 linear or branched alkyl, C.sub.1 to C.sub.6 linear or branched alkoxy, phenoxy or phenoxy substituted with one or more C.sub.1 to C.sub.6 linear or branched alkyl. The compounds display melatonin antagonist and are antiproliferative agents.