Sagami Chemical Research Center

Toa Eiyo Ltd.

Takeshi Nara

Masakatsu Shibasaki

Kentaro Kogi

Atsuo Takahashi

Tuyoshi Aoki

Takashi Yamaguchi

Yozo Nishimiya

A prostacyclin analogue having the formula: ##STR1## wherein R.sup.1 is --CO.sub.2 R.sup.5 (wherein R.sup.5 is a hydrogen atom, a straight chain or branched alkyl group having from 1 to 12 carbon atoms, an aralkyl group having from 7 to 12 carbon atoms, a cycloalkyl group having from 4 to 7 carbon atoms and unsubstituted or substituted by at least one alkyl group having from 1 to 4 carbon atoms, a substituted or unsubstituted phenyl group, or one equivalent of a cation), or --CONR.sup.6 R.sup.7 (wherein each of R.sup.6 and R.sup.7 is a hydrogen atom or an alkyl group having from 1 to 10 carbon atoms, or R.sup.6 and R.sup.7 together with the adjacent nitrogen atom, form a 5- or 6-membered substituted or unsubstituted hetero ring which may contain a hetero atom other than said nitrogen atom); A is --CH.sub.2 CH.sub.2 CH.sub.2 --, CH.sub.2 --O--CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 --O--CH.sub.2 -- or --CH.dbd.CHCH.sub.2 CH.sub. 2 --; B is trans --CH.dbd.CH-- or --C.tbd.C--; R.sup.2 is a straight chain or branched alkyl group having from 3 to 10 carbon atoms, a cycloalkyl group having from 4 to 7 carbon atoms and unsubstituted or substituted by at least one alkyl group having from 1 to 4 carbon atoms, a straight chain or branched alkenyl group having from 3 to 12 carbon atoms, a straight chain or branched alkynyl group having from 3 to 8 carbon atoms, or an alkyl group having from 1 to 3 carbon atoms substituted by a substituted or unsubstituted phenyl or phenoxy group, by an alkoxy group having from 1 to 6 carbon atoms or by a cycloalkyl group having from 5 to 8 carbon atoms; R.sup.3 is a hydrogen atom, a methyl group or a vinyl group; and R.sup.4 is a hydrogen atom, an acyl group having from 1 to 7 carbon atoms, a tri-C.sub.1 -C.sub.7 hydrocarbon-silyl group or a group capable of forming an acetal bond together with the oxygen atom of a hydroxyl group; provided that the double bond in a substituent for A is E or Z, or a mixture thereof; the asymmetric center in a substituent for R.sup.2 assumes a R-conformation or a S-conformation, or a mixture thereof; and the bonds shown by dotted lines at the 2-3 and 3-4 positions mean that either one of them is a double bond.

Prostacyclin analogue, and blood circulation improving agent and

Growing community of inventors

Fukushima, Japan

Takeshi Nara