SYNTHESIS AND STEREOCHEMISTRY OF REISSERT COMPOUNDS FROM BENZOTHIAZOLE

Benzothiazole Reissert compounds 1-5 were synthesized, characterized a nd alkylated to produce 6-9. Conformational analysis of 2 by the use o f high resolution (400 MHz) variable temperature NMR spectroscopy indi cated that the Z to E amide conformer ratio is 79:21 (+/-3%) in CDCl3 at 213 K (-60-degrees-C) and 57:43 (+/-3%) in C6D5CD3 at 213 K. Aromat ic solvent induced shifts were employed to determine the distribution of rotamers and indicated that the alkylated benzothiazole Reissert co mpound 8 existed in only the Z amide conformation. Hindered aryl-carbo nyl rotation was also detected in the Reissert compounds.