合成路线1

In a related procedure, alkylation of 2,4-dihydroxybenzaldehyde (VI) with chloride (II) gave ether (VII). Subsequent conversion of the aldehyde group of (VII) into the desired nitrile (X) was effected by the following sequence, including formation of the corresponding oxime (VIII), dehydration with concomitant acetylation using Ac2O, and then hydrolysis of acetate (IX) using K2CO3. Alternatively, aldehyde (VII) was directly converted to nitrile (X) by reaction with hydroxylamine-O-sulfonic acid, followed by basic treatment. Racemic alpha-bromo-(2-methylphenyl)acetic acid (XI) was resolved via formation of the corresponding salt with (-)-ephedrine (XII). Hydroxy nitrile (X) was then alkylated with the chiral bromide (XII), and the resulting compound was finally converted to the corresponding sodium salt.