Methods for crystallization of hydroxycarboxylic acids
AssigneeKaneka Corporation
InventorsMasafumi FUKAE, Yoshiro Hiraishi
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Abstract
The invention aims at producing high-purity crystals of a hydroxycarboxylic acid represented by the following formula (1): in high yield. Provided are a method for crystallization of a compound (1) which comprises acidifying a mixture of a solution of an alkali salt of the compound (1) and an organic solvent, and a method for crystallization of compound (1) by mixing a solution of the compound (1) in a water-miscible good solvent with water, in which a slurry with a necessary suspension amount of the compound (1) for inhibiting oil formation and scaling is prepared in advance and then a main crystallization is carried out in the presence of said slurry.
Claims21
1-41. (canceled)
A method for crystallization of a compound (1) of the following general formula (1):
- in which R is CH3, CH2OH, (CH2OCOR1, CO2R2, CONR3R4, OH, CH2OR1 or CH2NR3R4;
- R1 is a C1-5 alkyl group;
- R2 is H or a C1-5 alkyl group;
- R3 and R4 are independently selected from among H and C1-5 alkyl groups;
- a and b each is a double bond, one of a and b is a single bond with the other being a double bond or a and b each is a single bond,
- by mixing a solution of the compound (1) in a water-miscible good solvent with water,
- in which a slurry with a necessary suspension amount of the compound (1) for inhibiting oil formation and scaling of the compound (1) is prepared in advance and a main crystallization is then carried out in the presence of said slurry.
Dependencies are inferred from the claim text.