L-Cysteine hydrochloride monohydrate → HCID 131713429, compound

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Reaction Steps

An aqueous solution of L-malic acid (1200 ml, content of L-malic acid: 0.60 mole) is introduced into a column packed with a weak basic ion exchange resin (Diaion WA-10 (OH type), 600 ml) and thereby L-malic acid is adsorbed onto the resin. A solution of crystalline L-cysteine hydrochloride monohydrate (120 g, 0.683 mole) in water (1000 ml) is introduced into the above column and thereby there is obtained an aqueous solution of L-cysteine L-malate as an effluent. The aqueous solution (containing L-cysteine: 0.642 mole and L-malic acid: 0.439 mole is concentrated under reduced pressure so as to regulate the total amount to 256 g. To the resulting solution is added isopropyl alcohol (100 ml), and the mixture is allowed to stand at 10° C. in order to precipitate crystals well. The precipitated crystals are collected by filtration and air-dried at 50° C. overnight to give crystalline di-L-cysteine L-malate (106.1 g, yield: 82.5%).

Provenance & Evidence