S-triazine derivative and remedy for estrogen-dependent disease containing said derivative as effective component

A pharmaceutical composition for inhibiting aromatase enzymes, which comprises an effective amount of one or more s-triazine compounds having the formula (I) or a pharmaceutically-acceptable acid addition salt thereof:

• ##STR7## wherein:
• (1) when R.sub.1 and R.sub.2 are independent of each other or R.sub.3 and R.sub.4 are independent of each other, or both;
• R.sub.1 and R.sub.3 are each lower alkyl;
• R.sub.2 and R.sub.4 are each lower alkyl or phenyl which is unsubstituted or substituted with halogen, nitro or amino;
• with the proviso that at least one of R.sub.2 or R.sub.4 is phenyl which is unsubstituted or substituted with halogen, nitro or amino;
• (2) when R.sub.1 and R.sub.2 or R.sub.3 and R.sub.4, or both are, respectively, coupled with an neighboring nitrogen atom to form a cyclic amino group;
• NR.sub.1 R.sub.2 is 1-pyrrolidinyl;
• piperidino which is unsubstituted or substituted with phenyl;
• 1-piperazinyl which is unsubstituted or substituted with lower alkyl or phenyl;
• morpholino;
• or thiomorpholino;
• NR.sub.3 R.sub.4 is 1-aziridinyl which is unsubstituted or substituted with lower alkyl;
• 1-pyrrolidinyl which is unsubstituted or substituted with lower alkoxycarbonyl;
• piperidino which is unsubstituted or mono- or di-substituted with hydroxy, hydroxyl lower alkyl, lower alkoxycarbonyl, lower alkyl, cyano, phenyl or ethylenedioxy;
• 1-piperazinyl which is unsubstituted or substituted with lower alkyl, benzyl, phenyl which is unsubstituted or substituted with halogen, nitro or amino, pyridyl or pyrimidinyl;
• morpholino which is unsubstituted or mono- or di-substituted with lower alkyl;
• 3-thiazolidinyl;
• thiomorpholino;
• 1-imidazolyl which is unsubstituted or mono- or di-substituted with lower alkyl;
• or 1, 2, 4-triazole-1-yl and a pharmaceutically acceptable diluent or carrier.