Propylbutyrolactone and Tetrahydrofuryl propionic Acid

Submitted by Erwin Schwenk, Domenick Papa, Hilda Hankin, and Helen Ginsberg. 

In a 2-1. beaker resting on a hot plate and equipped with a mechanical stirrer are placed 150 g. of sodium hydroxide (Note 1) dissolved in 800 ml. of water and 41.4 g. (0.3 mole) of furyl-acrylic acid.1 The stirrer is started, and to the warm solution (Note 2) 100 g. of Raney nickel-aluminum alloy is added, in small portions, over a period of 4 4.5 hours (Notes 3 and 4). During the addition of the alloy, the temperature of the mixture is kept at 60-70° and then is raised to approximately 95° where it is held for an additional 2-3 hours, with stirring. From time to time sufficient water is added to the reaction mixture to maintain approximately the original volume. The hot solution is filtered by decantation, and the nickel residue (Note 5) is washed with two 50-ml. portions of hot 2% sodium hydroxide solution. The combined filtrates and washings are cooled and then immediately added slowly (Note 6), with good stirring, to 800 ml. of concentrated hydrochloric acid (Note 7). The solution at this point 

Solid sodium hydroxide is used in order to take advantage of the heat of solution. If the mixture at this stage is allowed to cool, it will be necessary to heat the solution to 50-60° before the addition of the alloy is begun. 

Some of the furylacrylic acid remains undissolved but goes into solution readily after the addition of the nickel-aluminum alloy is begun. 

If any excessive frothing occurs during the addition of the alloy, a few drops of octyl alcohol can be added from time to time. 

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