| abstract |
PCT No. PCT/EP94/00305 Sec. 371 Date Aug. 1, 1995 Sec. 102(e) Date Aug. 1, 1995 PCT Filed Feb. 1, 1994 PCT Pub. No. WO94/18178 PCT Pub. Date Aug. 18, 1994.A process for preparing a compound of structure (I) or a hydrate or solvate thereof in which R1 is C1-6alkyl, optionally substituted phenyl or optionally substituted phenylC1-6alkyl, which comprises reacting an azide of the structure (II): M(+)N3(-) with a cyanoformate of the structure (III): NC.CO2R1 in which M is an alkali metal atom, and R1 is as described for structure (I), to form an intermediate salt of structure (IV), in which R1 is as described for structure (I) and M is as described for structure (II) followed by conversion of the salt (IV) to the free tetrazole (I) or to a hydrate or solvate thereof. |