2-Sulfobenzoic acid anhydride opens cleanly with N-Boc-protected α-amino alcohols to afford zwitterionic esters 1,2-C6H4(SO3−)(CO2CH2CHR1NH3+) (R1 = H, alkyl), the species R1 = iPr is crystallographically characterised. Dehydration of these species affords zwitterionic oxazoline sulfonic acid derivatives 1,2-C6H4(SO3−)(CA=NH+CHR1CH2OA) (CA and OA are bonded C−O) for R1 = iPr (X-ray), iBu, tBu, CH2Ph. Reaction with water regenerates the zwitterionic esters while exposure to M(OAc)2 (M = Cu, Pd) leads to the formation of the crystallographically characterised complexes MIIL2 (L = anion of the iPr-oxazolinesulfonic acid). Heating either the zwitterionic esters or oxazolines with R2NH2 [R2 = CH2Ph, CH2(1-C10H7), R-CH(Me)Ph] leads to SN2 attack at the oxazoline methylene group leading to the amido sulfonic acids 1,2-C6H4(CONHCHRCH2NHR2)(SO3H) based on crystallographic studies on R1 = iPr, R2 = CH2(1-C10H7).