Hong-chang Shi, Jiajia Cao, Yuefei Hu
Mar 26, 2008
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Influential Citations
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Journal
Industrial & Engineering Chemistry Research
Abstract
In this article we proposed a novel procedure for the synthesis of efaproxiral sodium, including two reaction steps, condensation, and O-alkylation. In the condensation step, a convenient method was adopted to eliminate the use of solvents, i.e., 4-hydroxyphenylacetic acid and 3,5-dimethylaniline were heated at 150-180 °C for 3-5 h, and the reaction was successfully carried out. The yield of anilide in 4-hydroxyphenylacetic acid was 90-93%. In the O-alkylation step, the old circuitous process was avoided, and high-quality sodium salt was directly obtained with a yield of 90%. The final product of efaproxiral sodium was crystallized in water, yielding a new crystalline form containing a unique X-ray powder diffraction pattern with only one peak of 3.7° ± 0.2° in 2θ. The quality of the final product is high with a content of 99.51% according to high-performance liquid chromatographic detection. The present study provided a new environmentally friendly procedure for the preparation of efaproxiral sodium with high yield, low cost, and a short reaction pathway.