158results about How to "Starting materials are cheap and readily available" patented technology

The invention discloses a method for preparing medetomidine. Medetomidine can be effectively prepared according to the method for preparing medetomidine, and by adopting a cheap 4-imidazole derivative and cheap 1-(2,3-dimethylphenyl)ethanone as raw materials, the medetomidine product is prepared only through three-step reactions. The method has simple process conditions, is easy to control, and is conducive to industrialized mass production; and the yield of medetomidine prepared by the method for preparing medetomidine can reach 76%, and the product purity can reach 99.5%.

The invention relates to a preparation method of high-purity obeticholic acid. A compound chenodeoxycholic acid (CDCA) shown as a formula II is used as a starting raw material and subjected to oxidation, esterification, hydroxy protection, ethylidene formation, catalytic hydrogenation, carbonyl reduction and esterolysis reaction to obtain the high-purity obeticholic acid. The preparation method of the high-purity obeticholic acid, provided by the invention, has the advantages of low toxicity, low pollution, high purity, good stereoselectivity, low content of impurities, mild reaction conditions, high safety, simplicity and convenience in production operation and the like, and is suitable for industrial production.

The invention relates to a preparation method of a steroid drug intermediate, and concretely relates to a preparation method of a betamethasone intermediate which is 16beta-methyl-17alpha-hydroxypregna-4,9-diene-3,20-dione. The method comprises the following steps: carrying out a cyanidation reaction on 9alpha-hydroxy-4-ene-pregna-3,17-dione, carrying out a ketal protection reaction, carrying out a double elimination reaction, carrying out an epoxy reaction, and carrying out a Grignard addition hydrolysis reaction to prepare the target product. The method is a brand preparation technology for producing the betamethasone intermediate, and has the characteristics of cheap and easily available initial raw material, simple operations of all above reactions, high yield, suitableness for industrial massive production, and realization of the yield and the quality reaching satisfactory levels.

The invention relates to the field of pharmacy, in particular to a method for efficiently synthesizing an elagolix intermediate. The method takes 6-methyluracil as a starting material, and comprises five reactions of aminoalkylation, halogenation, coupling, benzyl halide substitution and deprotection. The synthetic method has the advantages that the starting material is cheap and easy to obtain, areaction reagent is friendly to the environment, the reaction steps are simple, the aftertreatment is convenient, the overall yield is higher, and the method is especially suitable for industrial mass production and has larger application value.

The invention relates to a preparation method for organosilicone ring bodies. The method comprises that the organosilicone ring bodies are obtained via synthesis and purification processes of synthesis, hydrolysis, pyrolysis and distillation after Grignard reaction of chlorobenzene (bromobenzene). The method has the advantages of readily available and low-price raw materials, stable technology, high security and no environmental pollution, short reaction steps and low cost, and is suitable for industrial production.

The invention relates to a synthesis process of methoxsalen. In the process, pyrogallol is used as an initial raw material, and the methoxsalen is prepared by carrying out six-step reaction on the pyrogallol, wherein the total yield is 29%. The synthesis process has the advantages of short synthesis path, simple method, readily-available raw materials and suitability for industrial production.

The invention discloses a one-pot method for preparing a crucial intermediate in oseltamivirphosphate synthesizing reaction. The method is characterized in that: 1,3-butadiene and ethyl propiolic acid ethyl ester are adopted as raw materials, alcohol and isocyanate / salt are adopted as main reactants, DBU is adopted as a catalyst, and no separation process is required before a finished product is obtained, such that the one-pot method is realized. The method mainly comprises steps that: 1, 1,3-butadiene is cooled to a temperature of -78 DEG C; ethyl propiolic acid ethyl ester and hydroquinone are added to 1,3-butadiene, and the mixture is stirred for 3 days under a temperature of 110 DEG C; the mixture is subject to vacuum distillation, such that 1-ethyl formate-1,4-diene cyclohexane is obtained; 2, I2 is added to a solution of 1-ethyl formate-1,4-diene cyclohexane and AgOCN; the mixture is heated to a temperature of 35-40 DEG C within 4 hours, such that a mixture A is obtained; alcohol and waterless HCl are added to the mixture A, and the mixture is stirred for 6-8 hours under a temperature of 35-40 DEG C, such that a mixture B is obtained; DBU is added to the mixture B, and the mixture is subject to a reaction over night under a temperature of 35-40 DEG C; the mixture is purified, such that the finished product is obtained; or DBU is added to the mixture A, the mixture is subject to a reaction over night under a temperature of 35-40 DEG C, and the mixture is purified, such that the finished product is obtained. Compared to existing technologies, the method is substantially advantaged in that: initial raw materials are cheap and easy to obtain, the reaction route is short, the synthesis period is shortened, the reaction method is improved into a one-pot method, the separation and purification processes are simple, the yield is high, the reaction efficiency is high, and the method has certain potential to be used in large-scaled productions.