摘要 |
The manufacture of 5-dichloroacetyl-3,3,6-trimethyl-9-oxo-1,5-diazabicyclo[4.3.0]-nonane I by the reaction of 3,3,6-trimethyl-9-oxo-1,5-diaza-bicyclo[4.3.0]nonane II with dichloroacetyl chloride in the presence of a solvent and a base, wherein a) this reaction is carried out in a two-phase system comprising a virtually water-insoluble organic solvent and water, and sodium or potassium hydroxide acting as the base is metered in at a rate corresponding to the rate of consumption of the dichloroacetyl chloride such that the aqueous phase exhibits a pH of from 7 to 9, and b) the resulting product is separated. |