To a solution of 4-[2-(2-phenylmorpholino)propyl]phenoxyacetic acid methyl ester hydrochloride (3.0 g; obtained from the mother liquors of Example (1) in methanol (50 ml) was added a 30% aqueous solution of methylamine (10 ml). This mixture was heated under reflux for 3 hours during which time 3 further 10 ml portions of the methylamine solution were added. The solution was cooled to room temperature, a further 10 ml portion of methylamine solution added, and the reaction mixture allowed to stand at room temperature overnight. The solvent was removed under vacuum, aqueous sodium carbonate added to the residue and extracted with dichloromethane (×2). The combined extracts were washed with brine (×2), dried over anhydrous magnesium sulphate, filtered and the filtrate evaporated to dryness. Chromatography of the residue on silica gel in 2% methanol-dichloromethane gave an oil, which, on treatment with an ethereal solution of hydrogen chloride, gave the title compound, m.p. 127°-130° C. (methanol-ethyl acetate-diethyl ether), as a 12:88 mixture of diastereoisomers.
