Chlorination reactions of ephedrines revisited. Stereochemistry and functional groups effect on the reaction mechanisms

Syntheses of optically active 2‐(2‐benzothiazolylimino)‐heterazolidines

“…Disodium N-(2-benzo- [18], 1R,2R-chlorodeoxy-norephedrine [18], and (1R,2S)-N,N -dimethyl-2-phenyl-3-methyl-1,3-diaminoethane [10] were prepared according to the literature.…”

An efficient synthesis of aziridines from ephedrines

“…Intermolecular NHÁ Á ÁCl À (2.21, 2.33 Å) and intramolecular Cl À Á Á ÁHN (2.34 Å) and NHÁ Á ÁO (2.48 Å) distances are in the range for hydrogen bonding interactions. 3 …”

“…The isochlorodeoxy-derivatives 8a and 8b were identified as intermediates in a solid mixture with the corresponding chlorodeoxy-derivatives 3a and 3b when the reactions of the corresponding chlorodeoxy-hydrochlorides 3a or 3b were reacted with two molar equivalents of K 2 CO 3 in refluxing chloroform for 72 h. (1S,2S)-Chlorodeoxypseudoephedrine hydrochloride 3a (1.0 g, 4.54 mmol) and K 2 CO 3 (1.88 g, 13.64 mmol) were dissolved in 5 mL of anhydrous ethanol and refluxed during 72 h, the resulted KHCO 3 and KCl in suspension were filtered off and ethanol was evaporated. The resulting mixture was dissolved in CHCl 3 .…”

“…The stereochemistry and functional group effects on the chlorination reaction mechanisms were revisited. 3 Recently, we reported the synthesis of 2-imineheterocycles from chlorodeoxypseudoephedrines hydrochlorides 3 and heterocyanates 2f to proceed through the cis-aziridinium 6, Scheme 1. This intermediate explains the retention of configuration in the heterocycle formed.…”

Chiral bis(amino alcohol)oxalamides as ligands for asymmetric catalysis. Ti(IV) catalyzed enantioselective addition of diethylzinc to aldehydes

“…14 Oxalamide 4 was prepared by direct condensation of methyl oxalate and L L-norephedrine in boiling toluene. 15 Oxalamides 5 and 6 bearing tertiary hydroxyl groups were obtained by condensation of the corresponding 2-substituted-2-amino-1,1-diphenylethanols 16 and oxalyl chloride. 2,2-Dimethylmalonamide 7 was obtained in a similar way.…”