Stereoselective Crystallization as a Key Step for the Synthesis of New Epimers of Captopril Derivatives
DOI:
https://doi.org/10.29356/jmcs.v51i4.1290Keywords:
Captopril, ACE inhibitor, antihypertensive, conjugate addition of thiolsAbstract
Abstract. The present work describes the synthesis of two new diastereomers of captopril derivatives. These epimers were achieved by conjugate addition of thioacetic acid and a-toluenethiol to a a,b-unsaturated system. The diastereomeric ratios obtained from this reaction were low at 0 °C and moderate at -50 °C. The importance of this synthesis, however, is that in one case, both epimers can be isolated in good yields. Their isolation was possible because of the high crystallinity showed by one epimer compared to the other one. The absolute configuration of the solid compound was established by X-ray analysis.
Resumen. El presente trabajo describe la síntesis de dos nuevos diastereómeros derivados del captopril. Estos epímeros fueron obtenidos a través de la adición conjugada del ácido tioacético y a-toluenotiol a un sistema a, b-insaturado. Las relaciones diastereoméricas para esta reacción fueron bajas a 0 °C y moderadas a -50 °C. Sin embargo, la importancia de esta síntesis radica en que, en un caso, ambos epímeros pueden ser separados en rendimientos químicos aceptables. La separación de los epímeros fue posible debido a la alta cristalinidad que presentó un epímero en comparación del otro. La configuración absoluta del epímero cristalino fue establecida por difracción de Rayos-X.
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