| 摘要 |
Prepn. of mono- and di-carboxylic acids from unsatd. fatty acids and/or derivs., comprises: (i) oxidising an unsatd. fatty acid, in the form of an acid and/or ester, with hydrogen peroxide in presence of a metal oxide or a carboxylic acid, opt. with a ruthenium catalyst; (ii) reacting the mixt. with nitric acid in presence of a vanadium catalyst, opt. with a co-catalyst; and (iii) recovering the mono- and di-carboxylic acids. The starting material is pref. a fatty acid with at least one double bond, an animal fat or oil, a vegetable oil, an ester of a pptd. fatty acid and is pref. oleic, colza, sunflower and soya oil. The ruthenium catalyst is pref. present in amt. of 1-35 % w.r.t. H2O2. H2O2 may be used with a gp. VIa metal catalyst, esp. a W and/or Mo catalyst in amt. of 1-35 (pref. 3-10) %, w.r.t. H2O2. The vanadium catalyst may be a V halide, a V oxide, a V oxyhalide, a V or vanadyl sulphate, an alkali metal or ammonium vanadate, or V acetylacetonate. The optional V co-catalyst may be based on a Gp. VIIa or VIII metal. A stoichiometric amt. of H2O2 or a 0-50 % excess is used with a carboxylic acid in a hydrogen peroxide : carboxylic acid molar ratio of 10-500 (pref. 10-40) %. |
