MULTISTAGE PROCESS FOR PREPARING ALKALI METAL SALTS OF SPECIFIC 4-HYDROXY-2-OXO-2,5-DIHYDROFURAN-3-CARBOXYLIC ESTERS
申请人:BAYER CROPSCIENCE AG
公开号:US20150210662A1
公开(公告)日:2015-07-30
The present invention relates to a multi-stage method for preparing alkali metal salts of specific 4-hydroxy-2-oxo-2,5-dihydrofuran-3-carboxylic esters of the formula (I),
in which M and R
1
are as defined in the description,
which proceeds from malonic ester and does not require isolation of intermediates.
Process for Preparing Dithiine-tetracarboxy-diimides
申请人:LUI Norbert
公开号:US20110275831A1
公开(公告)日:2011-11-10
The present invention relates to a new process for preparing dithiine-tetracarboxy-diimides
本发明涉及一种制备二硫代噻吩四羧酸二酰亚胺的新工艺。
[EN] TRAZODONE AND TRAZODONE HYDROCHLORIDE IN PURIFIED FORM<br/>[FR] TRAZODONE ET CHLORHYDRATE DE TRAZODONE SOUS FORME PURIFIÉE
申请人:ACRAF
公开号:WO2009019133A1
公开(公告)日:2009-02-12
A process of production of trazodone or trazodone hydrochloride that comprises the steps of: (a) preparing an organic phase comprising trazodone in at least one organic solvent; (b) preparing an aqueous phase comprising at least one basic compound; (c) mixing said aqueous phase with said organic phase; (d) heating at a temperature o at least 40°C for at least 30 minutes; (e) recovering said trazodone; and, optionally, (f) treating said trazodone with hydrochloric acid to obtain trazodone hydrochloride. Trazodone or trazodone hydrochloride comprising less than 15 ppm of alkylating substances, and a pharmaceutical composition comprising said trazodone hydrochloride.
Solventless synthesis of hydrophilic phenol ester derivatives
申请人:——
公开号:US20020058824A1
公开(公告)日:2002-05-16
Process for preparing benzenesulfonate salts from an appropriately substituted acid chloride and a hydroxybenzenesulfonic acid is conducted in the absence of solvent, in a molar excess of acid chloride and in the presence of a phase transfer catalyst selected from quaternary ammonium and quaternary phosphonium salts and the target reaction product. The molar excess of the acid chloride is used to reduce the occurrence of gelation in the product.
Improved process for preparing phenyl esters of substituted acids
申请人:E.I. DU PONT DE NEMOURS AND COMPANY
公开号:EP0402047A1
公开(公告)日:1990-12-12
Phenyl esters of substituted acids are prepared by a two-step process in which a phenol derivative is first treated with an acid halide to yield a phenyl ester intermediate, and the intermediate is reacted with an appropriate nucleophile.