Efficient Syntheses of Pyrofolic Acid and Pteroyl Azide, Reagents for the Production of Carboxyl-Differentiated Derivatives of Folic Acid Jin Luo Michael D. Smith Douglas A. Lantrip Susan Wang P. L. Fuchs 10.1021/ja971568j.s003 https://acs.figshare.com/articles/journal_contribution/Efficient_Syntheses_of_Pyrofolic_Acid_and_Pteroyl_Azide_Reagents_for_the_Production_of_Carboxyl-Differentiated_Derivatives_of_Folic_Acid/3666117 Reaction of folic acid (<b>1</b>) with excess trifluoroacetic anhydride provides access to both the previously unknown <i>N</i><sup>10</sup>-(trifluoroacetyl)pyrofolic acid (<b>8) </b>and pyrofolic acid (<b>9</b>). Reaction of either of these materials with hydrazine selectively affords pteroyl hydrazide (<b>13</b>), which may be oxidized to pteroyl azide (<b>27) </b>on a large scale (62% overall from <b>1</b> without the need for chromatography). Treatment of <b>27</b> with differentially protected glutamates provides a convenient and high-yielding synthesis of differentially protected, optically pure folates. 1997-10-22 00:00:00 Efficient Syntheses pteroyl hydrazide trifluoroacetic anhydride pyrofolic acid pteroyl azide differentially Pteroyl Azide folic acid