摘要:
The present invention relates to a simple economical process for the purification of an acid addition salt of a compound of Formula (III) contaminated with an acid addition salt of a compound of Formula (III'), which comprises washing at least once the addtion salt of the compound of Formula III with an organic solvent capable of removing the acid addition salt of the compound of Formula III' to obtain the acid addition salt of the compound of Formula III in chiral purity of greater than 99.5 % and chromatographic purity of greater than 99 %.