1-ARYLSULPHONYL, ARYL(THIO)CARBONYL PYRIDAZINO DERIVATIVES AND METHODS OF PREPARATION

1-Arylsulphonyl, arylcarbonyl and aryl(thio)carbonyl pyridazino derivatives and processes for making said derivatives are described. The novel derivatives are non-steroidal heterocyclic compounds which act as selective progestins and/or antiprogestins having a high in vitro affinity for either the uterine, breast or bone progestin receptor. As such, the non-steroidal heterocyclic derivatives are useful in contraception, menopause, osteoporosis or endometriosis.