申请人:TORAY INDUSTRIES, INC.
公开号:EP0924188A1
公开(公告)日:1999-06-23
Crystals of an aromatic 0,0'-diacyltartaric acid of the formula (VIII):
wherein R2 and R3 are the same as or different from one another and each is a hydrogen atom, halogen atom or C1 - C4 alkyl group are sufficiently uniform in size that 95% to 98% of them pass through a 20-mesh sieve. Such crystals may be prepared by hydrolyzing an aromatic carboxylic anhydride of the formula (IV):
wherein R2 and R3 are as defined above, to form the corresponding acid (VIII) in the form of an oil and crystallizing the acid in the presence of an organic solvent which is immiscible with water to form crystals of the hydrate of the acid (VIII). For the crystallization process, each of the organic solvent immiscible with water and seed crystals of the acid (VIII) are added to the oil of the acid (VIII) present in the reaction mixture.
式(VIII)的芳香族 0,0'-二酰酒石酸晶体:
其中 R2 和 R3 彼此相同或不同,且各自为氢原子、卤素原子或 C1 - C4 烷基,其大小足够均匀,95%-98% 的晶体可通过 20 目筛。这种晶体可以通过水解式(IV)的芳香族羧酸酐来制备:
其中 R2 和 R3 如上定义,形成油状的相应酸 (VIII),并在与水不溶的有机溶剂存在下使酸结晶,形成酸 (VIII) 的水合物晶体。在结晶过程中,将不溶于水的有机溶剂和酸 (VIII) 的种子晶体分别加入反应混合物中存在的酸 (VIII) 油中。