Processes for producing a compound represented by the formula (1), which includes an acrylic acid derivative and is useful as an agricultural chemical or medicine. One of the processes comprises the step of formulating a compound (3) and converting the OH of the resultant compound (2) into OR″. The first step comprises reacting a formic or orthoformic ester in the presence of a Lewis acid and a base. The second step comprises reacting the compound with R″OH or with R″OH and CH(OR″)
3
under acidic conditions or using a phase-transfer catalyst in a two-phase system and regulating the base and the concentration thereof to stereoselectively synthesize the target compound. In another, process, the compound is efficiently produced without isolating the compound. The compound can also be produced without the compound (2).
1
Disclosed is a process for preparing a diaryl oxalate which comprises the step of transesterifying a dialkyl oxalate or/and an alkylaryl oxalate with an aryl alcohol in the presence of a tetra(aryloxy)titanium as a catalyst, wherein the tetra(aryloxy)titanium is fed into a reaction system of the transesterification as an aryl alcohol solution of the tetra(aryloxy)titanium which is prepared by reacting a tetraalkoxy titanium and an excess amount of the aryl alcohol and removing a by-producing alkyl alcohol.
The present invention encompasses processes for the preparation of optically pure clopidogrel camphorsulfonic acid salt without the need to isolate or recover (±) clopidogrel.
本发明涵盖了制备光学纯的氯吡格雷针对石榴酸檄酸盐的过程,无需分离或回收(±)氯吡格雷。
Method for Producing Fluorine-Containing Cyclopropane Carboxylic Acid Compound
申请人:CENTRAL GLASS COMPANY, LIMITED
公开号:US20180186763A1
公开(公告)日:2018-07-05
The present invention provides an industrially applicable method for production of a fluorine-containing cyclopropane carboxylic acid compound useful as an intermediate for pharmaceutical and agrichemical products. A fluorine-containing cyclopropane monoester is obtained by: forming a fluorine-containing cyclic sulfate with the use of a fluorine-containing dial compound and sulfuryl fluoride (as a cyclic sulfuric esterification step); reacting the fluorine-containing cyclic sulfate with a malonic diester, thereby forming a fluorine-containing cyclopropane diester (as a cyclopropanation step); and hydrolyzing the fluorine-containing cyclopropane diester (as a hydrolysis step). The fluorine-containing cyclopropane carboxylic acid compound, such as fluorine-containing cyclopropane monoester or its salt, can be obtained with high chemical and optical purity by mixing the fluorine-containing cyclopropane monoester with an amine and subjecting the resulting salt of the fluorine-containing cyclopropane monoester and amine to recrystallization purification.