Patent ID: 6903234

Claim:
A method of making calcium-2-hydroxy-4-(mercaptomethyl)butanoate, the method including the steps of 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 being carried out over a first period of 3-120 seconds to produce a reaction mixture in the first reaction zone; transferring the resulting reaction mixture 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; and allowing heat generated by reaction between the 2-hydroxy-4-(mercaptomethyl)butanoic acid and the calcium salt in the second reaction zone to drive off sufficient water to produce a product mixture containing less than 5% (m/m) water.