A mixture of 41.4 g (0.3 mole) of 2-furanacrylic acid (see p. 48), m.p. 141°, 115 ml of 10% sodium hydroxide solution, and 300 ml of water was shaken in a one-liter glass cylinder having a ground-in stopper until the furanacrylic acid had dissolved completely. Over a period of 2.5–3 hours, 552 g (0.72 mole) of 3% sodium amalgam was added in small portions (Note 1). When the addition was complete, the alkaline solution was separated from mercury, filtered, and acidified to Congo red with concentrated hydrochloric acid (ice-water cooling) (Note 2). The aqueous solution containing precipitated acid was treated with 3–4 100-ml portions of ether. The combined ether extract was washed with a little water and dried over anhydrous sodium sulfate. Solvent was distilled off, and the residue was vacuum-distilled with collection of a substance of b.p. 134–136°/12 mm; the furanpropionic acid solidified completely in the receiver; m.p. 58° (Note 3).