167results about "Preparation from carboxylic acid amides" patented technology

The invention discloses a method for producing adipic acid, hexamethylenediamine hydrochloride and polyhexamethylene (di)guanidine chloride from waste nylon-66 serving as a raw amerial through depolymerization, which is characterized by comprising the following steps of: depolymerizing the waste nylon-66 by using hydrochloric acid to obtain refined adipic acid and hexamethylenediamine hydrochloride; polymerizing the hexamethylenediamine hydrochloride and dicyandiamide (in a molar ratio of 1:1) at the temperature of between 170 and 190DEG C for 1 to 3 hours to obtain a white or pale yellow solid polyhexamethylene diguanidine chloride; and adding dicyandiamide and ammonium chloride powder in a molar ratio of 1:2 into a reactor, performing reaction at high temperature for 1 to 3 hours, slowly adding hexamethylenediamine hydrochloride powder, continuously reacting for 3 to 7 hours to obtain a white or pale yellow solid polyhexamethylene guanidine chloride. The method improves production efficiency, reduces production cost, and solves the problems of difficult separation of the product hexamethylenediamine due to depolymerization, low yield and poor benefit; and the technological process is environment-friendly, simple and convenient, and is suitable for industrial production.

In one embodiment, the invention is to a process for purifying acetic anhydride. The process includes the steps of feeding a liquid crude acetic anhydride stream directly to a distillation column and separating the liquid crude acetic anhydride stream to produce a light ends stream, a sidedraw and a residue stream. The sidedraw comprises substantially pure acetic anhydride product. The distillation column is operated at a pressure less than 101 kPa. The substantially pure acetic anhydride product comprises greater than 98 wt. % acetic anhydride, has a permanganate time of greater than 10 minutes, and has an APHA color of less than 10.

The invention relates to a method for preparing 2,3,3,3-tetrafluoropropene. The method comprises the following steps: (1) by taking a by-product N,N-diethyl-2,3,3,3-tetrafluoropropylamide of an Ishikawa's reagent as a raw material, hydrolyzing under acidic or alkaline conditions to obtain 2,3,3,3-tetrafluoropropionic acid; (2) contacting the 2,3,3,3-tetrafluoropropionic acid with a reducing agentin the presence of a catalyst or in a catalyst-free system so as to obtain 2,3,3,3-tetrafluoropropanol; and (3) reacting the 2,3,3,3-tetrafluoropropanol in the presence of a dehydrating agent, therebyobtaining the 2,3,3,3-tetrafluoropropene. The method disclosed by the invention is simple in operation, mild in conditions and low in equipment requirements, recycling of the by-product is realized,and industrialized application is easily realized.

The present invention provides a catalyst precursor for producing maleic anhydride by oxidizing butane. Said catalyst precursor is prepared by a process comprising partially reducing V+5 to V+4 in a mixture of alcohols consisting of isobutanol and benzyl alcohol in a volume ratio of 2.5-5.0, then adding a phosphoric oxy-acid and an alkylsilicon in turn. The catalyst precursor prepared according to said process has a small pore volume, a relatively high bulk density in an appropriate pore size distribution.

A solid-supported palladium(II) complex which catalyzes the Mizoroki-Heck coupling reaction efficiently and a method of employing the solid-supported palladium(II) complex to synthesize cinnamic acid and derivatives thereof. The solid-supported palladium(II) complex is also stable and can be recycled without significantly losing catalytic activity.

This process is carried out in the presence of a solid catalyst comprising an active phase. The catalyst is formulated and the conversion is carried out in a medium essentially free of strong mineral acid.

Substituted heterocyclic compounds for treating multidrug resistance are disclosed. Compositions and methods of use for the substituted heterocyclic compounds are disclosed. Suitable substituted heterocyclic compounds include: 1

The present invention provides a method for manufacturing a high-purity aromatic nitrile compound and aromatic carboxylic acid compound safely, inexpensively, and with high efficiency. A compound (2)is subjected to the Willgerodt reaction in the presence of an additive as needed, and the resultant amide compound (3) is hydrolyzed and then neutralized, and a carboxylic acid compound (4) is obtained. The carboxylic acid compound (4) is reacted with a halogenating agent in an organic solvent in the presence of a catalyst as needed, then reacted with an amidating agent, the resultant amide compound (5) or (6) is reacted with a dehydrating agent, and a nitrile compound (1) is obtained. Alternatively, the carboxylic acid compound (4) is reacted with a halogenating agent and a compound represented by the formula R6SO2R7 in an organic solvent in the presence of a catalyst as needed, and a nitrile compound (1) is obtained. The symbol Np is a naphthyl group which may have a substituent, R5 represents a C1-3 alkylene group, and the other symbols are as described in the specification.