Vicarious nucleophilic substitution: a dramatically shortened synthesis of 2-amino-6-nitrobenzoic acid labelled with carbon-14

Literature preparations of 2-amino-6-nitrobenzoic acid are usually based on phthalic anhydride. In order to make [benzene-14C(U)]-2-amino-6-nitrobenzoic acid, [benzene-14C(U)]-phthalic anhydride has to be prepared in multiple steps from [14C(U)]-benzene, resulting in an unacceptably lengthy 14-step synthesis. We have been able to develop a completely different method of synthesis, producing [benzene-14C(U)]-2-amino-6-nitrobenzoic acid from [14C(U)]-benzene in just four steps with an overall radiochemical yield of 32%. Copyright © 2011 John Wiley & Sons, Ltd.