184 results about "Methylating Agent" patented technology

The invention includes methods of processing an initial di-carbonyl compound by conversion to a cyclic compound. The cyclic compound is reacted with an alkylating agent to form a derivative having an alkylated ring nitrogen. The invention encompasses a method of producing an N-alkyl product. Ammonia content of a solution is adjusted to produce a ratio of ammonia to di-carboxylate compound of from about 1:1 to about 1.5:1. An alkylating agent is added and the initial compound is alkylated and cyclized. The invention includes methods of making N-methyl pyrrolidinone (NMP). Aqueous ammonia and succinate is introduced into a vessel and ammonia is adjusted to provide a ratio of ammonia to succinate of less than 2:1. A methylating agent is reacted with succinate at a temperature of from greater than 100° C. to about 400° C. to produce N-methyl succinimide which is purified and hydrogenated to form NMP.

This invention relates to a method of efficiently producing a high-purity para-substituted aromatic hydrocarbon while suppressing caulking without requiring isomerization-adsorption separation steps, and more particularly to a method of producing a para-substituted aromatic hydrocarbon, characterized in that a methylating agent and an aromatic hydrocarbon are reacted in the presence of a catalyst formed by coating MFI type zeolite having a particle size of not more than 100 μm with a crystalline silicate.

This disclosure relates to a process of manufacturing para-xylene, comprising (a) contacting a pygas feedstock and methylating agent with a catalyst under reaction conditions to produce a product having para-xylene, wherein the product has higher para-xylene content than the para-xylene content of the pygas feedstock; and (b) separating the para-xylene from the product of the step (a), wherein the catalyst comprises a molecular sieve having a Diffusion Parameter for 2,2-dimethylbutane of about 0.1-15 sec−1 when measured at a temperature of 120° C. and a 2,2-dimethylbutane pressure of 8 kPa-a and the pygas comprises from about 1 to about 65 wt % benzene and from about 5 to 35 wt % toluene.

The invention provides a method for preparing guaiacol by a methanol method. Methanol used as a methylating agent and pyrocatechol are used for synthesizing the guaiacol under the action of a solid acid catalyst in a high pressure vessel. The solid acid catalyst used for synthesizing the guaiacol has low price, is friendly to environment and can be recycled. The invention is characterized in that the invention has simple preparation technology, mild reaction condition and short reaction time; the obtained guaiacol is light yellow clear transparent liquid and has good product quality, high yield, high selectivity and few side products; and all side products in reaction liquid can be recycled.

The invention relates to a method for synthesizing BTX aromatic methyl into unsym-trimethyl benzene. The method takes BTX aromatic hydrocarbon (comprising any one or more of benzene, toluene, o-xylene, m-xylene, p-xylene and mixed xylenes) and a methylating agent (selected from one or more of methyl alcohol, dimethyl ether and methane chloride) as raw materials to prepare unsym-trimethyl benzene by a methylation reaction under the catalytic action of an acid catalyst. The acid catalyst is selected from any one of halide, liquid acid, complexacid, heteropolyacid, solid super acid, acidic ion exchange resin, acidic oxide, hydrogenous zeolite molecular sieve or supported acid catalyst. The pressure of the methylation reaction is 0.01-10.0Mpa, the temperature is 30-700 DEG C, the mass space velocity of raw material liquid is 0.1-10.0h<-1>, and the mole ratio of the aromatic hydrocarbon and the methylating agent is 1:10 to 10:1. The methylation reaction can adopt a continuous fixed bed reaction or continuous stirred-tank reaction. The method has rich raw material resources, low cost, mild reaction condition as well as higher once-through conversion of the raw materials and yield of the unsym-trimethyl benzene.

Applicants have discovered a method for the stereoselective and regioselective synthesis of 3α-hydroxy, 3β-methyl-5α-pregnan-20-one (ganaxolone) comprising reacting 5α-pregnane-3,20-dione; with an organometallic methylating agent in an inert solvent to provide a compound of the formula

The invention relates to a method for preparing heterocyclic compounds of methyl mercapto under ionic liquid catalysis, including the followings: (1) mercapto heterocyclic compound and methyl carbonate with the mole ratio of 1: 1.2 to 2 are added to ionic liquid, and are heated to the temperature of 50 to 150 DEG C while stirring during the reaction of 0.5 to 15 hours; (2) after reaction, the temperature is decreased to room temperature to extract products, and the solvent is recycled after vacuum concentration, thus obtaining the compound. The method has the advantages of easy, simple and safe operation as well as obviously improved substrate conversion and product selectivity, and the methyl carbonate used as methylating agent and the ionic liquid used as solvent are environmentally friendly; and simultaneously the ionic liquid is easy to recycle and can be in cycle use.

The invention discloses a method for preparing methylnaltrexone bromide and belongs to the technical field of pharmaceutical engineering. The method comprises the following steps of: generating 3-O-t-butyl dimethyl silyl-naltrexone by taking naltrexone hydrochloride as a raw material, t-butyl dimethyl chlorosilane as a protection group and a dipolar aprotic solvent as a medium in the presence of organic base; reacting dimethyl carbonate serving as a methylating agent and the dipolar aprotic solvent serving as the medium with the dimethyl carbonate; and finally, reacting with solution of hydrobromic acid in the water serving as a medium, and distilling at reduced pressure to obtain the methylnaltrexone bromide. The protection group t-butyl dimethyl chlorosilane of phenolic hydroxyl is white solid, has no pungent odor, can generate stable intermediate products at normal temperature, has simple removal step, and is an ideal hydroxyl protective agent. The methylating agent dimethyl carbonate makes reaction environment-friendly, reaction yield higher, and technology simpler; the methylnaltrexone bromide is generated during deprotection; the steps are shortened; and the industrialized production is convenient.

A morphine component, e.g., a concentrate of poppy straw, is converted into codeine in high yield and high purity and in a highly controlled manner. The conversion process involves the following steps: (a) providing a solution or suspension of a morphine component in an inert solvent or a mixture of solvents; (b) methylating the resultant solution or suspension with a methylating agent in the presence of an alkaline ingredient; and (c) recovering the resultant codeine as the free base or as a salt.

The invention discloses a preparation method for producing ainothiazoly loximate by utilizing a phase transfer technology. The preparation method comprises the following steps: A, in an aqueous system, adding ethyl acetoacetate and sodium nitrite into a reaction kettle in proportion for reacting to obtain a nitrosation product; B, reacting the product of the ethyl acetoacetate subjected to nitrosation with a saturated aqueous solution of a methylating agent and sodium carbonate in the presence of a phase transfer catalyst by controlling the temperature, separating an aqueous layer after the reaction, and then directly carrying out chlorination; C, controlling the reaction temperature, introducing chlorine gas into the product subjected to the methylation, washing with water, and layering to obtain a chlorination reactant; D, adding thiourea, sodium acetate and phase transfer catalyst tetrabutyl ammonium chloride into the chlorination reactant, controlling the reaction temperature, and centrifugalizing the product; E, adding flake caustic soda and water into a cyclization product, regulating the pH value with hydrochloric acid, and centrifugalizing; and F, adding methyl alcohol into the centrifugalization product for refining, centrifugalizing and drying to obtain the ainothiazoly loximate. The method disclosed by the invention is easy to implement, is simple and convenient to operate, has low production cost, greatly improves the quality and yield of the product, and ensures safe and reliable production processes.