The present invention relates to a compound represented by the formula (I) ##STR00001## wherein R.sup.1 is a group represented by the formula ##STR00002## wherein R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are each independently a hydrogen atom or a C.sub.1-6 alkyl, or a salt thereof. The compound of the present invention is useful as an agent for the prophylaxis or treatment of circulatory diseases such as hypertension and the like and metabolic diseases such as diabetes and the like.
RELATED APPLICATIONS
This application is the National Phase filing of International Patent Application PCT/JP2005/003422, filed Feb. 23, 2005, and a continuation of U.S. patent application Ser. No. 11/031,057 which was filed Jan. 7, 2005, which claim priority to Japanese Patent Application 048928/2004, filed Feb. 25, 2004.
