| 摘要 |
Methacrylic acid and/or esters or amides thereof are prepared by reacting the a -nitrosation product of 2,2,5,5-tetramethyl-3-oxohydrofuran and/or a rearrangement product thereof with 1 to 20 mols of at least one compound of formula R.OH where R represents a hydrogen atom or an alkyl, aryl or alkenyl radical, in the presence of at least 0.6 mol of a dissociable poly-basic mineral acid, at a temperature in the range 75 DEG to 170 DEG C. The rearrangement products of the hydrofuran are a ,a 1-sec-dicarboxylic acid amide diisopropyl ether, a -mononitrile-a 1-mono-carboxylic acid diisopropyl ether and a ,a 1-dicarboxylic acid diisopropyl ether and esters thereof formed by adding water or organic solvents to the a -nitrosation products. The acids include sulphuric, pyrosulphuric, phosphoric, pyrophosphoric and polyphosphoric acids. Esterification catalysts and polymerization inhibitors may also be present. Examples describe the preparation of methacrylic acid, methyl methacrylate, and methacrylamide. |
