Process for the preparation of 1,3-diaza-spiro (4.4) non-1-en-4-one derivatives and 1-cyano-1-acylaminocyclopentane intermediates

A process for the preparation of a compound of formula (I), wherein R means hydrogen atom, or C1-6 alkyl group, or C7-12 aralkyl group or phenyl group, characterized in that

• a) the compound of formula (III) is reacted with a compound of formula (IV), wherein the meaning of R is the same as defined above, and X means halogen atom or C1-5 alkoxy group or hydroxyl group, and the resulting compound of formula (II), wherein the meaning of R is the same as given above, is transformed, in a reaction medium with pH above 7, into the compound of formula (I),
• wherein the meaning of R is as defined above;
• or
• b) the compound of formula (III) is reacted with an anhydride of formula (V), wherein the meaning of R is the same as defined above, and the resulting compound of formula (II), wherein the meaning of R is as given above, is transformed, in a reaction medium with pH above 7, into the compound of general formula (I);
• or
• c) a compound of formula (II), wherein the meaning of R is the same as defined above, is transformed, in a reaction medium with pH above 7, into the compound of formula (I), and optionally, the resulting compound of formula (I), before or after isolation, is transformed into an acid addition salt, or the compound of formula (I) is liberated from its acid addition salt