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96 results about "Dimethylformamide-dimethylacetal" patented technology

4-substituent-2-amido pyrimidine compound and preparation method thereof

The invention relates to a 4-substituent-2-amido pyrimidine compound and a preparation method thereof. The invention adopts a technical scheme of having a structure shown as general formula (I). The preparation method comprises the following steps that: an aromatic ring or heterocyclic ring compound with acetyl radicals is put into a container together with N, N-dimethyl formamide dimethyl acetal, and the mixture is evenly stirred, is heated until refluxing and reacts for 3 to 5 hours, the stirring is stopped, and the mixture is cooled to room temperature, filtered and dried to obtain an intermediate product; sodium ethylate or sodium methoxide is dissolved in absolute alcohol, the mixture is evenly stirred, guanidine hydrochloride is added into the mixture, the obtained mixture is stirred for 0.5 to 1.5 hours at room temperature, and A liquid is obtained; the intermediate product is dissolved in the absolute alcohol to obtain B liquid; and the B liquid is slowly dropped into the A liquid, the reaction system is heated until refluxing, the reaction is carried out for 5 to 7 hours, the stirring is stopped, and the obtained mixture is cooled to room temperature, stands overnight, is filtered, washed and dried. The invention has high yield, high purity, simple technology and universality.
Owner:丹东恒悦新材料有限公司

Method for synthesizing 2-chloro-3-amino-4-methylpyridine by ethyl cyanoacetate and acetone

The invention relates to a method for synthesizing an important intermediate 2-chloro-3-amino-4-methylpyridine for an anti-AIDS medicament Nevirapine, and belongs to the technical field of organic synthesis. The method comprises the following process steps that: ethyl cyanoacetate and acetone are dehydrated and condensed to generate a condensation compound I under the action of a catalyst; dimethyl formamide, dimethyl sulfate and sodium methoxide solution react to generate N,N-dimethylformamiade dimethyl acetal (N,N-dimethyl formamide A), and then the N,N-dimethylformamiade dimethyl acetal reacts with the condensation compound I to generate conjugated enamine, namely a condensation compound II; the condensation compound II is cyclized by hydrochloric acid and ethanol to form a cyclic compound 2-chloro-4-methyl-ethyl nicotinate; the 2-chloro-4-methyl-ethyl nicotinate is ammonolyzed by ammonia gas to form 2-chloro-4-methyl-niacinamide; and the 2-chloro-4-methyl-niacinamide is subjected to Hofmann degradation reaction to form the 2-chloro-3-amino-4-methylpyridine. Compared with the prior synthesizing method, the method of the invention has the remarkable characteristic of reducing the reaction steps, and is suitable for large-scale industrialized production; the molar total yield of the five-step reaction is improved to 27 percent from the prior 24 percent; and the purity of the product reaches over 99 percent.
Owner:江苏鼎昊医药科技有限公司

Preparation methods of 1,4,7,10-tetraazacyclododecane and nanofiltration membrane

The invention discloses a preparation method of 1,4,7,10-tetraazacyclododecane. The method comprises the following steps: adopting triethylene tetramine, methyl benzene and water to obtain a triethylene tetramine hydrated crystal substance; heating the triethylene tetramine hydrated crystal substance and the methyl benzene to react to obtain a triethylene tetramine-methyl benzene solution, and obtaining linear triethylene tetramine through drying, filtration and reduced pressure distillation; enabling the linear triethylene tetramine, N,N-dimethylformamide dimethylacetal and methyl benzene to react, and crystallizing to obtain clear crystal bis-imidazoline; enabling potassium carbonate, solvent acetonitrile, bis-imidazoline and 1,2-ethylene dibromide to react, and conducting reduced pressure distillation, washing and drying to obtain bromine; under the protection of nitrogen, adding a potassium hydroxide water solution, heating to a back flow state, dropwise adding a bromine salt water solution, and conducting filtration, precipitation, condensation, cooling and crystallization to obtain the 1,4,7,10-tetraazacyclododecane. The invention also provides a preparation method of a polyamide nanofiltration membrane. According to the invention, the purity of 1,4,7,10-tetraazacyclododecane is improved.
Owner:SHANGHAI INST OF TECH
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