| 摘要 |
A process for the preparation of monocarboxylic or bicarboxylic acids by oxidative scission of olefins or of their corresponding vicinal dihydroxy compounds. An olefin of formula R1-CH = CH-R2 or R1-CH = CH2 or a vicinal dihydroxy compound of formula R1-CHOH-CHOH-R2 or R1-CHOH-CH2OH (wherein R1 and R2 represent hydrocarbon groups such as alkyls, cycloalkyls, aryls and alkylaryls, and wherein moreover R1 and R2 may be bound to each other so as to form an alkenyl or alkyl cycle) is reacted, under vigorous stirring, with H2O2 at a temperature from 0 DEG C to 120 DEG C and under a pressure of from 1 to 100 atmospheres. There is used an aqueous phase containing H2O2 and an organic phase comprising a solvent, the olefin or the vicinal dihydroxy compound and a catalyst. In the case of an olefin, the catalyst is a composition of the formula:
Q3XW4O24-2n
wherein:
Q represents an onium (R5R6R7R8M) cation;
M is N. P. As or Sb;
X is P or As; and
n is 0, 1 or 2;
while in the case of a vicinal dihydroxy compound the catalyst is one of the composition Q3XW4O24-2n or is a catalyst obtained by reacting tungstic acid or an alkali tungstate with hydrogen peroxide and an onium Q Y salt (wherein Y is an inorganic anion) at a pH value below 2. |
