Freezing the Butterfly Motion of Carbamazepine Derivatives

Atropisomeric properties were found in carbamazepine derivatives. The atropisomers of N -acyl and N -thiocarbamoyl derivatives of carbamazepine were isolated, with high stereochemical stability. It has been elucidated that the rotation about the N–C1′ axis around the outer amide N–(C=O) does not coordinate with the rotation of the butterfly-like motion.