36results about "Preparation from carboxylic acid nitrogen analogues" patented technology

Production of 2-octyl-3,4-di(7-isocyanate caprylic)-1-hexyl cyclohexane and fatty isocyanate containing it is carried out by hydrogenation catalyzing for dimmer acid between room temperature to 280 deg. C, dewatering for generated saturated dimmer acid, reacting with sulfurous chloride, reacting dimeric acid acyl bromide with sodium azide to generate dimeric acid azide, isomerization decomposing to convert into final product. It can be used to produce polyurethane varnish, elastomer, adhesive, spinning finishing agent and rocket impeller.

The invention provides a type of aliphatic diisocyanate with a novel chemical structure, which is C21-36 aliphatic diisocyanate, has the same excellent performance with other traditional aliphatic isocyanates, and is used for preparing polyurethane varnish, coating, elastomer, adhesive, textile finishing agent, rocket propellant and the like. The invention also provides a preparation method of this type of substance, which comprises the following steps that: (a) unsaturated dicarboxylic acid with a special structure or the ester solution thereof are catalyzed and hydrogenised to prepare saturated diacid; (b) the saturated diacid is dissolved into inert solvent and added with chloride agent to react and prepare binary acid chloride; (c) sodium azide is added in to react and prepare the corresponding azide; and (d) the azide is isomerized and decomposed to prepare an aliphatic diisocyanate crude product. The method is characterized by lower condition requirements, safety, environmental-friendliness, fewer side effects, high yield and easy wide popularization in industry.

The invention discloses a method for synthesizing trans-1,4-cyclohexane diisocyanate, which comprises the following steps: (1) mixing trans-1,4-cyclohexanedicarboxylic acid with thionyl chloride, heating under reflux, decompressing and recovering the extra thionyl chloride for obtaining trans-1,4-cyclohexanedicarbonyl chloride; (2) adding toluene, benzene or xylene into the trans-1,4-cyclohexanedicarbonyl chloride, heating to 45-75 DEG C, and further adding sodium azide for obtaining mixture; and (3) keeping the temperature of the mixture for 0.5-1.5 hours at the temperature of 45-75 DEG C, filtering for removing insoluble matters, decompressing, recovering the toluene and distilling for obtaining the trans-1,4-cyclohexane diisocyanate. The synthesis method has the advantages of simple process route, easy obtainment of raw materials and short reaction period, thereby being applicable to industrial mass production.

The present invention discloses a method for preparing diisocyanate by thermally separating diamino formic ether. The method comprises the following steps that fatty group or alicyclic group diamino formic ether undergoes a thermal decomposition reaction for 0.5 to 2.5 hours in the presence of a catalyst at a reaction pressure of between 1.0 and 1.5 atmospheric pressure and a reaction temperature of between 50 and 240 DEG C so as to form fatty group or alicyclic group diisocyanate. The catalyst is easy to obtain and can be recycled, the reaction conditions are mild, the cost and the energy dissipation are reduced, the byproduct of the reaction is recoverable alcohol that does not cause contamination to environment, and thus the method is more suitable for the large scale industrial production.

The invention discloses a synthesis method of dimer(fatty acid)yl diisocyanate, which comprises the steps of: adding a methylbenzene solution of dimer(tall oil acid) and dimethylformamide into a reaction bulb, dropping a methylbenzene solution containing di(trichloromethyl) carbonic ester under the stirring at a temperature of 70-80 DEG C, reacting for 1h, filtering, evaporating to remove methylbenzene to obtain dimer(tall oil acid) acyl chloride, wherein the mol ratio of the dimer(tall oil acid) to the di(trichloromethyl) carbonic ester is 3:1-1.5; adding sodium azide and deionized water into the reaction bulb, dropping an acetone solution dissolved with the dimer(tall oil acid) acyl chloride under the stirring, adding 300ml of normal hexane, dimixing, washing a normal hexane layer by using cold water, drying by using anhydrous sodium sulfate to obtain an anhydrous sodium sulfate solution of dimer(tall oil acid) acyl azide, wherein the mol ratio of the dimer(tall oil acid) acyl chloride to the sodium azide is 1:2-2.2; and adding 300ml of normal hexane into the reaction bulb, dropping the normal hexane solution under the stirring at a temperature of 65-70 DEG C, and continuing to react for 30min after the dropping to obtain a target product.

A carbamate compound is disclosed.

The invention discloses isocyanate with an inflaming retarding characteristic and a preparation method and application thereof, and belongs to the technical field of inflaming retarding coatings. Isophthalic acid is taken as a raw material, and the 1-bromine-3,5-diisocyanate benzene with the inflaming retarding characteristic is synthesized. The preparation method comprises the following steps of(1) preparation of 5-bromine-isophthalyl chloride; (2) preparation of 5-bromine 2-nitrine; (3) preparation of the 1-bromine-3,5-diisocyanate benzene. According to the preparation method, based on thephysicochemical property of an original coating, the non-toxic and fire-proof effects are added for the coating, a production technology and the preparation method are simple, there are no complex processes, the quality of the prepared product is stable, and the isocyanate is suitable for large-scale production, wide in market prospect and high in social and economic benefits.

The present invention provides bio-based aromatic diisocyanate of formula (I). [Formula should be inserted here] wherein X is OCH₃, Y is selected from —H or OCH₃, and m=0-12. The present invention further provides a method for preparation of aromatic diisocyanate of formula (I) useful for preparation of polyurethane.

A method for producing urethane compounds includes allowing a primary amine, a urea and/or an N-unsubstituted carbamate, and an alcohol to react in the presence of a compound containing a noncoordinating anion and a metal atom as a catalyst.

The invention discloses a method for synthesizing n-butyl isocyanate. The method comprises the following steps: weighing n-valeric acid and thionyl chloride according to the mole ratio of 1: 1, putting n-valeric acid and thionyl chloride in a round-bottomed flask, enabling an opening of the round-bottomed flask to be connected to a reflux condensing tube, of which an upper opening is provided with a calcium chloride drying tube, carrying out magnetic stirring, heating the round-bottomed flask to the temperature of 60-70 DEG C in oil bath, and carrying out reaction for 4-5 hours, so as to obtain a n-valeryl chloride crude product; and dissolving the crude product and a catalyst in an anhydrous toluene solvent, heating the solution to the temperature of 60-80 DEG C in a three-necked flask, enabling the three-necked flask to be connected to a thermometer, a reflux condensing tube, of which an upper opening is provided with a calcium chloride drying tube, and a flask cork respectively, carrying out magnetic stirring for 5-8 minutes, then, slowly adding drying sodium azide, of which the mole is equal to that of n-valeric acid, carrying out reaction until no gas is produced, keeping the reaction for 10-15 minutes, then, filtering out insolubles, and carrying out rotary evaporation to remove toluene, thereby obtaining n-butyl isocyanate. The method has the advantages of high yield, mild reaction conditions, simplicity in operation, short reaction time and little environmental pollution.

Low chlorine, multi-staged method for producing cycloaliphatic diisocyanates. The invention relates to a multi-staged method for the continuous low-chlorine production of cycloaliphatic diisocyanates, comprising the synthesis of diaminodipheynl alkanes, the hydration thereof into the corresponding cycloaliphatic diamines and the subsequent conversion of cycloaliphatic diamines to the corresponding cycloalkylene biscarbamates and the thermal cleaving of the latter into the cycloaliphatic diisocyanates and alcohol.

Provided is a reaction accelerator used in a reaction between a compound having an isocyanate group that does not directly bond to an aromatic ring, in each molecule, and a compound having an active hydrogren-containing group. The reaction accelerator comprises a compound having a carbamoyl halide group. Also provided is a production method whereby: the compound having a isocyanate group that does not directly bond to an aromatic ring, in each molecule, and the compound having an active hydrogren-containing group are caused to react; and a urethane compound, a thiourethane compound, an amide compound, or a urea compound are produced. The production method is characterized by said reaction occurring in the presence of the reaction accelerator.

A preparation process of 3-chloro-5-nitrotoluene is provided in mild conditions. It is a process for preparing 3-chloro-5-nitrotoluene, which comprises reacting 2-methyl-4-nitroaniline with a chlorinating agent such as 5-butyl hypochlorite in a neutral condition to obtain 2-chloro-4-nitro-6-methylaniline and deaminating the 2-chloro-4-nitro-6-methylaniline to obtain 3-chloro-5-nitrotoluene.

The invention provides a preparation method of C21-36 alicyclic diisocyanate and use. The preparation method comprises the following steps of: preparing an unsaturated alicyclic binary acid based on dehydrated ricinoleic acid or ester and a double bond containing fatty acid or ester as raw materials; preparing a saturated alicyclic binary acid through hydrogenation reaction; preparing acyl chloride of the alicyclic binary acid by acylating chlorination; preparing a trinitride of alicyclic binary acid by nitriding reaction; and finally preparing the alicyclic diisocyanate through isomerized decomposition reaction. According to the invention, acid or ester extracted from castor oil is used as a basic material, so that the production raw material is easy to get and low in cost, and prepared alicyclic diisocyanate is single in structure, less in side reaction and small in production difficulty, and the molecular weight is within a range of 300-500. According to the method, a same solvent is used in later three steps to the benefit of industrialization. The whole process is simple to operate, mild in condition, environment-friendly, safe in production, and is very beneficial for industrial popularization and application.

A novel process is described for the synthesis of Sitagliptin, IUPAC name 7-[(3R)-3-amino-1-oxo-4-(2,4,5-trifluorophenyl)butyl]-5,6,7,8-tetrahydro-3-(trifluoromethyl)-1,2,4-triazolo[4,3-a]pyrazine, of formula (I).

The invention relates to a multistage process for continuous and phosgene-free preparation of cycloaliphatic diisocyanates.

The invention relates to a preparation method and application of isocyanate, particularly relates to a preparation method of C4-C6 aliphatic isocyanate prepared from nylon acid as a raw material, and an application of the C4-C6 aliphatic isocyanate, and belongs to the technical fields of organic synthesis, adhesive chemistry and composite materials. The C4-C6 aliphatic isocyanate is prepared from urea and nylon acid as raw materials in manners of firstly preparing C4-6 aliphatic amide and reacting the C4-6 aliphatic amide with oxalyl chloride. The isocyanate is applied to preparation of polyurethane foaming plastic, rubber, elastic fibers, coatings, and bonding wood based composite materials.

The invention discloses a synthesis method of 4-isothiocyanato-2-(trifluoromethyl)benzonitrile. The synthesis method comprises the following steps: with 3-trifluoromethyl-4-cyanobenzoic acid as an initial raw material, firstly, subjecting 3-trifluoromethyl-4-cyanobenzoic acid to reacting with diphenyl azidophosphate under an anhydrous condition to generate 4-isocyanato-2-(trifluoromethyl)benzonitrile, and then subjecting 4-isocyanato-2-(trifluoromethyl)benzonitrile to reacting with a Lawson reagent to obtain the compound 4-isothiocyanato-2-(trifluoromethyl)benzonitrile. The method has the advantages of simple synthetic route, one-pot reaction, mild reaction conditions, simple post-treatment, high product yield (wherein total yield is greater than or equal to 83.9%), and easy industrial production.