To a solution of cyanuric chloride (1.84 gr) in acetonitrile (20 ml), kept at a temperature of −20° C. under stirring, dropwise were subsequently added solutions of 3,4-methylenedioxy-aniline (1.37 gr) in acetonitrile (20 ml) and diisopropylethylamine (DIPEA) (1.29 gr) in acetonitrile (20 ml). After stirring at −20° C. for 1 hour, again dropwise were subsequently added solutions of DIPEA (1.29 gr) in acetonitrile (20 ml) and (1 S,2R)-(+)-norephedrine (1.51 gr) in acetonitrile (20 ml). The mixture was allowed to warm to room temperature and was stirred for another 2 hours. The resulting reaction mixture was concentrated in vacuo. After addition of ethylacetate (250 ml) the organic layer was subsequently washed with a solution of HCl in water (1M, 100 ml), a solution of NaOH in water (1 M, 100 ml) and brine (50 ml). The organic layer was dried over sodiumsulphate, filtered and concentrated in vacuo. The resulting product was purified by column chromatography using silicagel and a mixture of heptane: ethylacetate (3:1) as the eluent. The resulting pure product (formula (9), see above, example B-44, see table) was obtained as a white solid in 80% yield.
