Acrivastine → (E)-3-(6-(3-(Pyrrolidin-1-yl)-1-(p-tolyl)prop-1-en-1-yl)pyridin-2-yl)propanoic Acid

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Reaction Steps

A solution of compound 2, vide supra, (3 g) in alcohol (100 mL) containing Raney nickel (1 g) was stirred under hydrogen at room temperature and pressure until the calculated quantity of hydrogen had been absorbed (ca. 45 minutes). The reduced ester was recovered by filtration and evaporation and purified by column chromatography on silica gel using petroleum ether as eluent. Butyllithium (10 mL, 1.64M in hexane) was added under nitrogen to a stirred suspension of triphenyl-2-pyrrolidinoethylphosphonium bromide (7.2 g) in dry toluene (75 mL) to prepare a Wittig reagent. Treatment of this ester with Wittig reagent by the method of Example 1 followed by saponification gave a mixture of two isomeric acids which were separated by fractional crystallization from ethyl acetate/petroleum ether mixtures. The less soluble E isomer, 3-{6-[3-Pyrrolidino-1-(4-tolyl)prop-1E-enyl]-2-pyridyl]-propionic acid (Compound B), melted at 156°-157°.

Provenance & Evidence