alpha-Trifluoromethyl-substituted alpha-amino acid esters 1 give N-formyl alpha-trifluoromethyl alpha-amino acid esters 2 on reaction with formic acid/acetic anhydride. 3,3,3-Trifluoro-2-isocyanopropionates 3 are obtained from 2 upon treatment with diphosgene/triethylamine.