hydrazone (CAS NO.: ), which is known as 2-Propanone, hydrazone, could be produced through the following synthetic routes.

A. Acetone azine (CAS NO.: ). A 500-ml., round-bottomed flask containing 145 g. (183 ml., 2.50 moles) of acetone is fitted with a mechanical stirrer and a dropping funnel and cooled in an ice bath. With vigorous stirring, 65.5 g. (1.31 moles) of 100% hydrate is added at such a rate that the temperature is maintained below 35°. The addition takes 20–30 minutes. The mixture is stirred for an additional 10–15 minutes before 50 g. of potassium hydroxide pellets is added with vigorous stirring and continued cooling. The upper liquid layer is separated and allowed to stand over 25 g. of potassium hydroxide pellets for 30 minutes, with occasional swirling. After filtration, the liquid is further dried with two successive 12.5-g. portions of potassium hydroxide. Distillation gives 120–126 g. (86–90%) of almost colorless acetone azine, b.p. 128–131°, n_D22 1.4538.

B. Acetone hydrazone (CAS NO.: ). Anhydrous hydrazine is prepared by heating under reflux 100% hydrazine hydrate with an equal weight of sodium hydroxide pellets for 2 hours, followed by distillation in a slow stream of nitrogen introduced through a capillary leak. (Caution! Distillation in air can lead to explosion.) The distillate boils at 114–116° and the yield is 95–97%.

A mixture of 112 g. (1.00 mole) of acetone azine and 32 g. (1.0 mole) of anhydrous hydrazine is placed in a 300-ml. round-bottomed flask fitted with a reflux air condenser and drying tube, and kept at 100° for 12–16 hours. (Caution! This reaction and the subsequent distillation should be carried out behind a protective screen.) The crude product is then distilled rapidly through a water-cooled condenser, and the colorless fraction boiling at 122–126° is collected, n_D22 1.4607, yielding 111–127 g. (77–88%) of essentially pure acetone hydrazone.

Notice: Hydrazine is toxic and should be handled in a hood. Anhydrous hydrazine is extremely reactive with oxidizing agents (including air) and should always be prepared and used behind a protective screen.