Patent ID: 7399879

Claim:
A process for the preparation of 2-alkylidene-1,4-dions derivatives, of formula (Ia) or (Ib) or a mixture of (Ia) and (Ib): wherein R 1 , R 2 and R 3 , equal to or different from each other, are hydrogen atoms or C 1 –C 20 hydrocarbon groups optionally containing heteroatoms belonging to group 13-17 of the periodic table, or R 1 and R 2 can join together to form a saturated or unsaturated C 3 –C 10 ring optionally containing heteroatoms belonging to group 13-17 of the periodic table, with the proviso that when R 1 and R 2 are both hydrogen atoms, only compounds of formula (Ia) are obtained; T 1 and T 2 , equal to or different from each other, are H, OR 4 , R 4 , NR 4 2 , SR 4 or PR 4 2 ; or T 1 and T 2 can be fused in an oxygen atom or a NR 4 group; R 4 , equal to or different from each other, are a C 1 –C 20 hydrocarbon group, optionally containing one or more heteroatoms belonging to group 13-17 of the periodic table; said process comprising the step of reacting a compound of formula (II): with a compound of formula (IIIa) or (IIIb): in the presence of at least one equivalent with respect to the compound of formula (IIIa) or (IIIb) of a carbonate of metal M or of a compound of formula MT j wherein j is equal to the valence of the metal M; M is a metal of groups 1–12 of the periodic table; T is OH − , HCO3 − , RO − or RC(O)O − wherein R is a linear or branched, saturated or unsaturated C 1 –C 20 -alkyl, C 3 –C 20 -cycloalkyl, C 6 –C 20 -aryl, C 7 –C 20 -alkylaryl or C 7 –C 20 -arylalkyl radical, optionally containing one or more halogen atoms.