PROCESS FOR THE PREPARATION OF FURYL DERIVATIVES OF 16-SUBSTITUTED PROSTAGLANDINS

The present invention relates to new furyl derivatives of 16-substituted prostaglandins, to a process for their preparation and to pharmaceutical and veterinary compositions containing them. The new compounds of the invention are optically active or racemic prostaglandins of the following formula (I) (I) wherein R is (1) -OH or -OR' wherein R' is C1-C6 alkyl optionally substituted by phenyl or by a monocycloalkyl group or by a pentatomic or hexatomic heteromonocyclic ring containing at least one heteroatom chosen from O, S and N; (2) wherein each of R'' and R''', is independently, hydrogen; C1-C6 alkyl; phenyl; or a pentatomic or hexatomic heteromonocyclic ring containing at least one heteroatom chosen from O, S and N; or R'' and R''', together with the nitrogen atom to which they are linked, form a pentatomic or hexatomic heteromonocyclic ring optionally containing a further heteroatom chosen from O, S and N; (3) -W-(CH2)n-X wherein W is -O- or -NH-, n is an integer of 1 to 4 and X represents a group -OR' or a group wherein R', R'' and R''' are as defined above; one of R1 and R2 is hydrogen and the other is hydroxy or R1 and R2, taken together, form an oxo group; one of R3 and R4 is hydrogen and the other is hydroxy; one of R5 and R6 is hydroxy and the other is hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, or phenyl; one of R7 and R8 is hydrogen and the other is a C1-C4 alkyl or tri-halo-C1-C4 alkyl group; m is an integer of 1 to 3; R9 is a 2-furyl or 3-furyl group, optionally substituted by one or more substituents chosen from C1-C4 alkyl, C1-C4 alkoxy, tri-halo-C1-C4 alkyl and halogen; and the symbol represents a single bond or a cis double bond.