(S)-(-)-1,2-Diaminopropane dihydrochloride

White solid

(S)-(-)-1,2-Diaminopropane dihydrochloride may be used in the preparation of following chiral imidazoline derivatives, which show moderate α-adrenergic blocking activity:

• (S)-(-)-4-methyl-2-(1-naphthylmethyl)imidazoline hydrochloride
• (S)-(-)-2-benzyl-4-methylimidazoline picrate
• (S )-(-)-2-[(2,6-dichlorophenyl)imino]-4-methylimidazolidine hydrochloride

(S)-(-)-1,2-Diaminopropane Dihydrochloride is used in the synthesis of Dexrazoxane, a cardiac medicine.

Preparation of (S)-(-)-diaminopropane dihydrochloride: 30.0g of D-(-)-tartaric acid and 105mL of water and 8.0g of ()-1,2-propanediamine were added sequentially in a reaction flask, stirred to dissolve, cooled, added dropwise, and warmed to reflux for 2 hours with stirring. Stirring was stopped, the temperature was first raised to 80 C, held for 1 hour, then gradually and slowly cooled down to room temperature, filtered, and dried under vacuum to give 16.1 g of (S)-1,2-propanediamine ditartrate. Add 16.1g (S)-1,2-propanediamine ditartrate and 150mL water in a reaction flask, heat to dissolve, then add 7.43g potassium chloride and 20mL water to form a solution, and keep warm and stir at 70 for 2 hours. Cooling, refrigerator static precipitation crystals. Filtered, the filtrate was distilled to dryness under reduced pressure to give 5.1 g of yellow solid (3) in 84% yield, []20D = -4.02 (C = 1%, H2O).