Compounds of formula (I), ##STR00001## or pharmaceutically acceptable derivatives thereof, wherein R represents H, C.sub.1-6 alkyl, SO.sub.2R.sup.1, SO.sub.2NR.sup.1R.sup.2, or COR.sup.1; R.sup.1 and R.sup.2 independently represent C.sub.1-6 alkyl; and Ring A represents a phenyl ring or a pyridinyl ring; may be useful in the treatment of anxiety, cardiovascular disease (including angina, atherosclerosis, hypertension, heart failure, edema, hypernatremia), dysmenorrhoea (primary and secondary), endometriosis, emesis (including motion sickness), intrauterine growth retardation, inflammation (including rheumatoid arthritis), mittlesmerchz, preclampsia, premature ejaculation, premature (preterm) labor and Raynaud's disease.