76 results about "4-methylthiazole" patented technology

The invention discloses a preparation method for febuxostat. The preparation method for febuxostat comprises the following steps of: by using 4-hydroxybenzonitrile and thioacetamide as raw materials, and reacting in hydrochloric acid solution to prepare 4-hydroxythiobenzamide; carrying out a reaction on 4-hydroxythiobenzamide and 2-chloroacetoacetic acid ethyl ester to prepare 2-(4-hydroxylphenyl)-4-methylthiazol-5-carboxylic acid ethyl ester; carrying out a reaction on the obtained compound and hexamine in the mixed acid system of methanesulfonic acid and trifluoroacetic acid to prepare 2-(3-formyl-4-hydroxylphenyl)-4-methylthiazole-5-carboxylic acid ethyl ester; synthesising 2-(3-nitrile-4-isobutoxylphenyl) -4-methylthiazole-5-carboxylic acid ethyl ester from the compound, hydroxylamine hydrochloride, potassium carbonate, iso-butyl bromide and the like in a polar protonic solvent via a one-pot method; and finally hydrolyzing in an alkaline condition to obtain the target product, namely, febuxostat. The total yield of the preparation method for febuxostat disclosed by the invention is increased to 66%, the separation steps are reduced, any extremely toxic substance is not involved, and the environmental pollution is less.

The invention discloses a peach essence. The peach essence consists of the following ingredients: propanediol, hexanol, hexenyl phenylacetate, benzaldehyde, ethyl acetate, phenylacetic acid cis-3-ester hexane, methyl acetate, hexyl acetate, hexyl trans-2-ester hexane, ethyl maltol, leaf alcohol, hexanal, acetic acid, linalool, gamma-caprylolactone, theta-decalactone, gama-decalactone, gamma-undecalactone, 8-mercaptomenthone, 2-isopropyl-4-methylthiazole, beta- damascenone, ethyl caprate and ethyl benzoate. The peach essence is moderate in fragrance, saturated, thick, stable in quality, natural in flavor and approximat to the natural fragrance of peach.

The invention discloses a method for synthesizing isoquinoline ketone compounds. The method includes that dual-core salicylic acid copper complexes which are cheap and easy to synthesize are taken as catalyzers, oxygen which is green, environment-friendly and nontoxic is taken as an oxidizing agent, chlorine salt, 3-benzyl-5-(2-hydroxy ethyl) -4-methyl thiazole moiety or thiamine hydrochloride are taken as auxiliary catalizers, and 2-aryl-1,2,3,4-tetrahydroisoquinoline compounds are subjected to further reaction to obtain the isoquinoline ketone compounds. The method is simple in operation, the catalyzers are cheap and easy to obtain, reaction conditions are moderate, product yield is high, shortcomings that traditional raw material reagents are high in price, harsh in condition, complex in synthesizing step, low in overall yield and the like are overcome, and good application prospect is achieved.

The invention relates to a method for synthesizing cefditoren pivoxil. The method comprises that D-7ACA reacts with an oxidizing reagent to produce a compound 1, the compound 1 is protected through silanization to produce a compound 2, 4-methylthiazole-5-methanol and NaI undergo an iodination reaction in the presence of a small amount of sulfuric acid for catalysis, triphenylphosphine is added into the reaction system and undergoes a reaction to produce a compound 3, the compound 3 is added into the compound 2 liquid and undergoes a reaction, the reaction product is concentrated, methanol anda small amount of concentrated hydrochloric acid are added into the concentrated product, the concentrated product is deprotected and crystallized to form cefditoren mother nucleuses, 7-ATCA and an AEactive ester undergo a reaction under alkaline conditions, the reaction product is crystallized to form a cefditoren sodium wet product, the cefditoren sodium wet product is added into iodomethyl pivalate and undergoes a reaction in the presence of a phase transfer catalyst and the product is crystallized to form a cefditoren pivoxil crude product. In preparation of the compound 1, cefditoren sodium and cefditoren pivoxil, single solvents are used and are easy to recover. The method has the advantages of simple operation, high product conversion rate, few impurities and low production cost and is suitable for industrial production of cefditoren pivoxil.

The invention provides a preparation method of 2-(3-formyl-4-isobutoxy phenyl)-4-methyl thiazole-5-ethyl formate which is obtained by using 4-isobutoxy cyanophenyl as an initial raw material and through a series of reactions. The invention also provides a preparation method of febuxostat, which comprises the following steps: reacting 2-(3-formyl-4-isobutoxy phenyl)-4-methyl thiazole-5-ethyl formate with hydroxylamine hydrochloride under the action of a catalyst to obtain a compound with a structure as shown in formula (VIII); hydrolyzing the compound with the structure as shown in formula (VIII) under an alkaline condition, and performing acidification to obtain febuxostat. The preparation method of the invention prepares febuxostat without using cyanides, and is high in safety. The preparation methods of the invention are simple in operation and high in yield. Experiment results show that the yield of step (A) is up to 90%, the yield of step (B) is up to 85%, the yield of step (C) is up to 90%, the yield of step (D) is up to 90%, and the yield of step (E) is up to 97%.

The invention relates to a new method for synthesizing thiabendazole. Acetone and chlorine are taken as starting materials to synthesize chloroacetone, chloroacetone not subjected to separation can directly react with thiocarbamide to obtain 2-Amino-4-methylthiazole which is subjected to diazotization to obtain 4-methylthiazole, and 4-methylthiazole is oxidized to produce 4-thiazolecarboxylic acid, and finally, 4-thiazolecarboxylic acid reacts with o-phenylenediamine to obtain the target object thiabendazole. The thiabendazole is a broad-spectrum anthelmintic, can repel roundworms, hookworms, whipworms, pinworms, strongyloises stercoralis and trichinization, is also a broad-spectrum efficient disinfectant and is widely used as a fruit fresh-keeping agent and a bactericidal mildew inhibitor in various fields over the past decade in China.

The invention provides a synthesis method of a dithiazole quaternary ammonium salt, which comprises the following steps of: when R is equal to R', step one, adding iodo n-heptane in 2,4-dimethylthiazole for reaction to obtain 2,4-dimethyl-3-heptyl thiazole-3-onium iodo salt, step two, carrying out reaction on 4-methylthiazole-2-mercaptan and iodo n-heptane to obtain a product 3-heptyl-4-methylthiazole-2(3H)-sulfoketone, step three, carrying out reaction on the product in the step two and iodo n-heptane to obtain an intermediate 3-heptyl-2-heptyl sulfenyl-4-methylthiazole-3-onium iodo salt, and step four, carrying out reaction on the products in the steps three and one in the presence of organic alkali to obtain yellow dithiazole quaternary ammonium salt; and when R is not equal to R', replacing the alkyl substituent group R' on N in the step two by R' different from the step one. According to the synthesis method, the generation of by-products is avoided, the final product is easy to separate, and the purity and the yield are high, so that the synthesis method is easy for large-scale industrial production and application.

The invention discloses a method for synthesizing ethyl 4-methylthiazole-5-formate employing a single step. The method comprises the following steps: reacting at 100-180 DEG C for 2-6 hours after mixing 2-chloroacetoacetic acid ethyl ester and ammonium thiocyanate; adding water to dissolve generated ammonium chloride after reaction is finished, and then filtering and drying, so as to obtain ethyl 4-methylthiazole-5-formate, wherein the molar ratio of 2-chloroacetoacetic acid ethyl ester to ammonium thiocyanate is 1:1.01 to 1:1.5. Compared with the prior art, the method has the characteristics as follows: 1, no solvent is used in a reaction process, 2 the method adopts single step synthesis, and is fewer in steps and simple and convenient to operate, and 3, the poisonous and harmful or flammable and combustible raw materials are not used, and the pressure for environmental protection is greatly reduced.

The invention discloses a 1, 4-pentadiene-3-one derivative containing thioether triazole, a preparation method and application. The structural general formula is shown as the specification, wherein Xis 2-O or 4-O, R is phenyl, substituted phenyl, heterocyclyl or 4-methylthiazole. The 1, 4-pentadiene-3-one derivative containing thioether triazole provided by the invention has good control effect on tobacco mosaic virus, ralstonia solanacearum and Xanthomonas oryzae pv. oryzae.

The invention relates to a preparation method of 4-methylthiazol. The invention aims at solving the problem that in the existing method for preparing the methylthiazol, the reaction route is long, the reaction is complicated and not easy to control, the production cost of the used catalyst is high and the yield is high. The preparation method comprises the following steps of A, mixing formamide, anhydrous glycol dimethyl ether and phosphorus pentasulfide, heating the mixture to be reacted at the temperature of 45 to 50 DEG C, and filtering the mixture to obtain thioformamide; B, adding chloroacetone into the thioformamide to be reacted at the temperature of 50 to 60 DEG C, adjusting the pH value to 6 to 7, and cooling, filtering, washing and dehydrating the mixture to obtain the 4-methylthiazol. Raw materials are cheap and easy to obtain, the reaction condition is moderate, the synthesis step is simple, no catalyst is used, no pollution exists, the yield is high, operation is simple and convenient, and the solvent can be recycled. The preparation method is applied to the technical field of chemical industry.

The invention relates to a new epoxidation method of 2-benzylidene-1,3-indan diketone double bond. The method comprises the following steps of: adding 2-benzylidene-1,3-indan diketone, phenyl isothiocyanate, 3-benzyl-5-(2-ethoxy)-4-methyl thiazole chlorate and triethylamine in a molar ratio of 1:0.25:0.25:0.25 into a reaction container containing a certain amount of ethanol, stirring at room temperature until the reaction is ended, steaming and removing the ethanol, and carrying out thin layer chromatography separation on residues to obtain the epoxidized product of 2-benzylidene-1,3-indan diketone double bond. By adopting the method, the defects that substrates are destroyed due to strong oxidation property of hydrogen peroxide in the double-bond epoxidation method by using hydrogen peroxide as the epoxidation reagent and epoxidation products cannot be synthesized from highly conjugated double bonds by the method are overcome. The method is simple to operate, low in energy consumption and high in productivity, and heating is not required.

The invention discloses a preparation method of 3-[(4-amino-2-methyl-5-pyrimidinyl) methyl]-5-(2-sulfonyl oxy ethyl)-4-methylthiazole. The preparation method comprises the step that vitamin B1 is in contact with a sulfonating agent in the existence of an organic solvent under the condition of a sulfuric acid esterification reaction. By adopting the method disclosed by the invention, products with higher purity can be obtained; and besides, the preparation method is simple, reaction raw materials are easy to obtain, the reaction condition is wild and the reaction products are easy to separate and purify. The preparation method of the 3-[(4-amino-2-methyl-5-pyrimidinyl) methyl]-5-(2-sulfonyl oxy ethyl)-4-methylthiazole, which is provided by the invention, has the advantages that a guarantee is provided for the identification of important related substances used during the production of the vitamin B1, and an evidence is provided for the improvement on the quality of the vitamin B1 in the production process at the same time.