HPTLC: A valuable tool to elucidate the mechanism of the intramolecular N-N' acyl transfer in alkylenediamine derivatives

LILIANA R. ORELLI; ANA M. REVERDITO; ISABEL A. PERILLO; BEATRIZ M. FERNÁNDEZ

Journal of Planar Chromatography

Alfred Huethig Publishers

Año: 1991 vol. 4 p. 406 - 409

0000-0000

HPTLC is a useful technique for elucidating the mechanisms of organic reactions and for monitoring their kinetics when other methods, such as direct UV spectrophotometry or HPLC, fail. The kinetics of the basic hydrolysis of a tetrahydropyrimidinium salt has been followed by HPTLC with post elution UV spectrophotometry. Although the reaction could not be followed by other methods, HPTLC revealed that it occurred through the formation and decomposition of a heterocyclic intermediate. The resulting open product, an acyltrimethylenediamine derivative, undergoes in neutral or alkaline media an intramolecular N>N?-acyl transfer to give the corresponding open isomer. Here again, HPTLC demonstrated that this migration occurred via the same heterocyclic intermediate. Plots of absorbance against time obtained using the chromatographic technique were compared with those measured by direct UV; very close pseudo first-order rate constants were calculated in both cases.