| 摘要 |
PURPOSE:To obtain the titled compound useful as a synthetic intermediate for medicines and agricultural chemicals industrially and advantageously in high yield, by reacting diketene with carbon monoxide and a nitrous acid ester in the presence of a palladium halide or a complex thereof. CONSTITUTION:Diketene of formula I is reacted with carbon monoxide and a nitrous acid ester of formula II (R is alkyl or cyclolalkyl) in the presence of a palladium halide, e.g. palladium chloride, or a complex thereof, e.g. formula III (X is halogen; L is 1-20C alkyl or phenyl), to give an acetonedicarboxylic acid diester of formula IV. The reaction is carried out under 0.01-100atm partial pressure of carbon monoxide at -10-+250 deg.C, preferably 15-150 deg.C, reaction temperature. The diketene is introduced at once into the system before the reaction, but preferably injected into the reaction system to suppress side reactions. The concentration of the diketene in the system is preferably kept at 0.1- 30wt%. |
