Synthesis of deuterium‐labeled 2‐quinoxalinecarboxylic acid and 3‐methylquinoxaline‐2‐carboxylic acid from deuterium aniline

Abstract

An efficient and simple synthetic route of deuterium-labeled 2-quinoxalinecarboxylic acid-d (QCA-d ) and 3-methylquinoxaline-2-carboxylic acid-d (MQCA-d ) is presented with 99.9% and 99.6% isotopic enrichment using aniline-d as labeled starting material. Their chemical structures were confirmed by H NMR, and their isotopic abundance was determined by mass spectrometry analysis.