| 摘要 |
In the present invention there is disclosed a process for preparing 2,4,5-tribromopyrrole-3-carbonitrile. The invented preparation process is characterized by reacting vinamidine salt of the general formula I, in which R, Ri1, Ri2 and Ri3 represent each independently on each other an alkyl group containing 1 to 4 carbon atoms or R and Ri1 or Ri2 and Ri3 together form each five-membered or six-membered ring, in which the grouping RRi1 or Ri2Ri3 represents each the group of the general formula -(CHi2)i4- or -(CHi2)i5-; and Xe- represents anion with glycine ester of the general formula {Hi2NCHi2COi2Ri4}, wherein Ri4 represents an alkyl group having 1 to 4 carbon atoms and a first base in the presence of a first solvent under formation of a mixture containing 4-cyanopyrrole-2-carboxylic acid and 4-cyanopyrrole-2-carboxylate of the general formula III, wherein Ri4 is as specified above. The obtained mixture is then subjected to hydrolysis by a second base in the presence of a second solvent under formation of 4-cyanopyrrole-2-carboxylic acid salt. The 4-cyanopyrrole-2-carboxylic acid salt is then brought into reaction with a third base and a bromination agent in the presence of a third solvent under formation of a desired 2,4,5-tribromopyrrole-3-carbonitrile. The invented 2,4,5-tribromopyrrole-3-carbonitrile is usable as moluscocidal agent.
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