| abstract |
The invention relates to a catalyst for the reaction of formaldehyde or an appropriate source thereof with a carboxylic acid or ester in order to produce an ethylenically unsaturated carboxylic acid or ester, preferably ethylenically unsaturated β-acid or ester. The catalyst comprises a metal oxide having at least two types of metal cations, M1 and M2 and where M1 is at least one metal selected from group 3 or 4 in periods 4-6 of the periodic table; group 13 in the 3rd to 5th periods of the periodic table, or the remaining elements in the lanthanide series (i.e. scandium, yttrium, lanthanide elements, titanium, zirconium, hafnium, aluminum, gallium, indium) and M2 is at least a metal selected from group 5 in the 5th to 6th periods of the periodic table or group 15 in the 4th to 5th periods of the periodic table (i.e. niobium, tantalum, arsenic and antimony). The invention extends to a process for producing an ethylenically unsaturated carboxylic acid or ester, preferably ethylenically unsaturated β-carboxylic acid or ester. The process includes the steps of reacting formaldehyde or an appropriate source thereof with a carboxylic acid or ester, optionally in the presence of the catalyst effective to catalyze the reaction. |