Water → Ispronicline hemigalactarate

(2S)-(4E)-N-Methyl-5-(5-isopropoxy-3-pyridyl)-4-penten-2-amine (2.00 g, 8.55 mmol) was dissolved in ethyl alcohol (20 mL), assisted by warming to 70° C. The warm solution was treated with galactaric acid (900 mg, 4.27 mmol) in one portion, followed by the dropwise addition of water (0.5 mL). The solution was filtered while hot to remove some insoluble material. The filtrate was allowed to cool to ambient temperature. The resulting crystals were filtered, washed with anhydrous diethyl ether, and dried under vacuum at 40° C. to yield a white, crystalline powder (750 mg, 26.0%), mp 140-143° C.