Add time:07/16/2019         Source:sciencedirect.com

Acid promoted cyclisation of homochiral (R)-N-(3,4-dimethoxyphenethyl)-halostachine proceeds with almost total racemisation to yield 1-phenyl-N-methyl-1,2,4,5-tetrahydrobenz[d]azepine (e.e. 6%). Coordination of the cyclisation precursor to the tricarbonylchromium(0) moiety renders the cyclisation completely stereospecific to afford, after decomplexation, homochiral (+)-(R)-1 -phenyl-N-methyl-1,2,4,5-tetrahydrobenz[d]azepine. (−)-(1R,2S)-N-(3,4-Dimethoxyphenethyl)ephedrine undergoes acid mediated cyclisation to furnish trans-(−)-(1R,2S)-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine as a single diastereoisomer. In contrast, the epimeric cyclisation precursor (−)-(1R,2R)-N-(3,4-dimethoxyphenethyl)pseudoephedrine cyclises to give a mixture (ratio 91:9) of trans- and cis-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine. However, cyclisation of the tricarbonylchromium(0) complex of(−)-(1R,2R)-N-(3,4-dimethoxyphenethyl)pseudo-ephedrine is completely stercoselective to yield trans-(+)-(1S,2R)-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine after decomplexation.

We also recommend Trading Suppliers and Manufacturers of [4-(3,4-DIMETHOXY-PHENYL)-THIAZOL-2-YL]-ACETONITRILE (cas 380348-77-6). Pls Click Website Link as below: cas 380348-77-6 suppliers