| 摘要 |
The reaction between a 5-cyano-1-hydrocarbylpyrrole-2-acetic acid and an aryl Grignard compound to produce a ketimine salt-containing reaction intermediate is improved by performing such reaction in an aromatic ether reaction medium at a temperature above about 100 DEG C. As compared to the previously known process, the reaction rate is markedly increased without loss of selectivity. Also, the water insolubility of aromatic ethers simplifies product work-up and recovery, reduces product losses, and facilitates solvent recovery and recycle. Preferably, the aryl Grignard reagent is prepared at the outset in tetrahydrofuran or methyl tetrahydrofuran-solvents in which such Grignard reagents are readily and safely produced. The resultant Grignard solution may then be employed in forming the aromatic ether-containing reaction medium in which the above reaction is conducted.
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