Process for base-promoted condensation reactions and base reagent therefor
申请人:Crompton Corporation
公开号:US06410795B1
公开(公告)日:2002-06-25
A method for the preparation of 1,3-diketones is disclosed wherein the method comprises the steps of:
(A) mixing an alkali metal base with a hindered alcohol in an aromatic hydrocarbon solvent;
(B) boiling the mixture and azeotropically distilling water formed by the reaction between the base and the alcohol, whereby a solution of a hindered alkali metal alkoxide is formed in situ in the solvent;
(C) mixing an ester with the solution of the hindered alkali metal alkoxide in the aromatic hydrocarbon solvent; and then
(D) adding a ketone to the mixture.
heterogeneous catalyst exhibits advantages over its homogeneous counterpart in the synthesis of β-hydroxyesters from epoxides. However, leaching of cobaltate from the catalytic support decreases the selectivity and recyclability of the catalyst. To overcome such drawbacks, a bis-imidazolium-based covalenttriazineframework (CTF) is employed as a catalytic support for the hydroesterification catalyst to reduce
Processes for preparing novel methylene blue derivative
申请人:Vig Rakesh
公开号:US20050107607A1
公开(公告)日:2005-05-19
Methods for the preparation of 7-(dipropylamino)pheno-thiazin-3-ylidene]-dipropylamine
制备7-(二丙基氨基)苯并噻嗪-3-基亚甲基]-二丙胺的方法
Pyridine derivatives having anti-ulcerative activity
申请人:Eisai Co., Ltd.
公开号:US05045552A1
公开(公告)日:1991-09-03
Pyridine derivatives useful for preventing or treating peptic ulcers, pharmaceutical preparations and methods of treating peptic ulcers are described.
本发明描述了用于预防或治疗消化性溃疡的吡啶衍生物、制药制剂和治疗消化性溃疡的方法。
Bis-propyl amine analog and composition
申请人:——
公开号:US20040152017A1
公开(公告)日:2004-08-05
Copy-protected optical medium utilizing a composition comprising a transient optical state change security materials capable of changing optical state when exposed to a wavelength of about 630 nm to about 660 nm and an electron transfer agent.