Preparation
In a 250 ml reaction flask, add 50 ml of water and 5.4 g of sodium hydroxide. Cool the reaction mixture to 0–5 °C. Add 4.7 g of liquid bromine dropwise to the reaction mixture. After the addition is complete, stir at 0–5 °C for 2 hours. Add 5.0 g of 3-fluoro-4-pyridinecarboxamide to the reaction flask. Stir at 0–5 °C for 2 hours until the solid is completely dissolved. Heat the reaction mixture to 85 °C. Maintain the reaction at 85 °C for 6 hours. Cool the reaction mixture to room temperature. Add 50 ml of ethyl acetate to the reaction flask to extract the product. Separate the organic layer and extract the aqueous layer twice with ethyl acetate. Combine the organic layers. 3.0 g of the pale brownish-red solid powder product, 4-amino-3-fluoropyridine, was obtained by drying and evaporating the solvent, with a yield of 81% and a purity of 96%.
Uses
4-Amino-3-fluoropyridine is an important intermediate in the synthesis of many new drugs, and it is an intermediate in the synthesis of transforming growth factor-β inhibitors and thrombin inhibitors.
