Identification of isomers of alkylaminophenylethanethiosulfuric acids by 13C-NMR calculations using a C-13 chemical shift user database and 2D NMR techniques

Abstract

In the synthesis of N-alkylaminoalkanethiosulfuric acids, there exists the possibility of forming two products in the last step of the synthesis. In the case of the seven acids synthesized in this laboratory from styrene oxide and primary aliphatic amines, the common spectroscopic methods were inadequate for distinguishing which of the two isomers was obtained. Carbon-13 chemical shift calculations employing the ACD/CNMR program were helpful, but not conclusive for identifying the products. The use of HMQC, HMBC and TOCSY techniques permitted the identification of the products as the 2-(N-alkylamino)-1-phenyl-1-ethanethiosulfuric acids.

Keywords

• aminoalkanethiosulfates
• 2D NMR techniques
• empirical calculations