| 主权项 |
1. A process for preparing a compound of formula (I)in which
R1 and R2 are identical or different and are hydrogen, or are C1-C8-alkyl which is optionally substituted with one or more halogen, —OR3, and/or —COR4, are C3-C7-cycloalkyl which is optionally substituted with one or more halogen, C1-C4-alkyl or C1-C4-haloalkyl, or are aryl or aryl-(C1-C4-alkyl) each of which is optionally substituted with one or more halogen, C1-C 1-C4-haloalkyl, —COR4 or sulphonylamino, R3 is hydrogen, C1-C4-alkyl or C1-C4-alkylcarbonyl or is aryl which is optionally substituted with one or more halogen, C1-C4-alkyl or Ci-C4-haloalkyl, R4 is hydroxyl, C1-C4-alkyl or C1-C4-alkoxy , comprising: (1) reacting a succinic monoamide of formula (VI) in which R is R1 or R2 with an excess of thionyl chloride, optionally in the presence of a diluent, (2) removing thionyl chloride to form a first product mixture; and (3) adding an organic solvent, water and a phase transfer catalyst to the first product mixture and after a reaction time of between 5 minutes and 24 hours converting, into a second product mixture comprising a compound of formula (I), wherein the phase transfer catalyst is selected from the group consisting of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulphate, benzyldodecyldimethylammonium chloride, dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, methyltrioctylammonium chloride, methyltridecylammonium chloride, a mixture of methyltrioctylammonium chloride and methyltridecylammonium chloride, tetraoctylammonium bromide, and didecyldimethylammonium chloride. |
