N-Aryl Phenylglycine O-Alkyl Esters의 간편한 합성 및 에스테르 치환반응

Synthesis of N-Aryl Phenylglycine O-Alkyl Esters and Its Substitution of Ester Moiety

For the development of new synthesis method for unnatural amino acid esters. N- aryl phenylglycine O-alkyl esters 4a~I were synthesized through esterification, bromination, C-N bond formation from commercially available phenylacetic acids. An efficient and practical reaction condition for esters 2a~c was that the starting materials 1a~c were refluxed in absolute methanol for 3 hours with catalytic concentrated hydrosulfuric acid. In addition, bromines 3a~c were formated for 3 h in dichloromethane at rt with N-bromosuccinimide. Bromines 3a~c were also converted to 4a~I through substitution of arylamines during refluxing for 24 hours in ethanol with triethylamine. Interestingly, ethyl esters 5a~c were formed via transesterification reaction when the p-sulfamylanilino group was used as a nucleophile in ethanol solvent.