Derivatization of N-methyl and cyclic amino acids with dimethylformamide dimethyl acetal

Six amino acids containing either an N-methyl or a cyclic secondary amine were converted to volatile derivatives by reaction with dimethylformamide dimethyl acetal. The amine functionalities were formylated by way of an amide acetal intermediate while the carboxylic acid groups were esterified directly. The resulting N-formyl esters were stable to solvent extraction and exhibited gas chromatography-mass spectrometry properties suitable for assay development.