| 摘要 |
Prepn. of diazinone (I) comprises: (a) reacting isopropyl amidinehydrochloride (II) with methylacetoacetate in a non-aq. system in the presence of a weak base; and (b) converting the 2-isopropyl-4-methyl-6- hydroxypyrimidine (III) formed into the K salt by reacting (III) in methyl-isobutyl ketone opt. mixed with at least one aliphatic solvent with KOH or K2CO3 under reflux and with azeotropic removal of the water formed and then reacting the K-salt of (III) with diethylthiophosphonylchloride to give (I). The base used in step (a) is pref. NaHCO3, K2CO3, KHCO3 or CaCO3, but in esp. Na2CO3. Pref. water is simultaneously distd. off during step (a) and the solvent chosen is pref. one from which water can be azeotropically distd. and is esp. petroleum ether (in partic. 60-80), cyclohexane and/or methylisobutyl ketone. The solvent in step (b) is pref. methylisobutylketone opt. mixed with petroleum ether 60-140, petroleum ether 60-80 or cyclohexane in ratio 1:9-9:1. In step (b) pref. solid KOH or K2CO3 are used. USE/ADVANTAGE - (I) is an insecticide amd acaricide. The process gives high yield in short reaction times. The (I) produced is nearly colourless and of high purity. There is no need to produce a catalyst. |
