A method of making a calcium salt of 2-hydroxy-4-(mercaptomethyl)butanoic acid

摘要

A method of making calcium-2-hydroxy-4-(mercaptomethyl)butanoate includes combining and mixing 2-hydroxy-4-(mercaptomethyl)butanoic acid and a calcium salt selected from calcium oxide and calcium hydroxide and water in a first reaction zone. The combining and mixing step is carried out over a first period of 3-120 seconds. The resulting reaction mixture is transferred at the end of the first period from the first reaction zone to a second reaction zone, the transferring step being carried out over a second period of 3-60 seconds. Heat generated by reaction between the 2-hydroxy-4-(mercaptomethyl)butanoic acid and the calcium salt in the second reaction zone is allowed to drive off sufficient water to produce a product mixture containing less than 5% (m/m) water.