cas 1801-06-5, 4-Chloro-5-fluoro-2-methoxypyrimidine

Articles about 1801-06-5Total 6 be found

Preparation method of 5- flucytosine
The invention belongs to the technical field of chemical synthesis of medicines and relates to a preparation method of 5-flucytosine. The preparation method comprises the following steps: utilizing ethyl formate and methyl chloroformate to synthesize 2-chloro-3-oxo methyl propionate, then utilizing oxymethylisourea to close rings to obtain pyrimidine rings, utilizing potassium fluoride to substitute chlorine on the pyrimidine rings, utilizing phosphorus oxytrichloride to substitute hydroxyl groups on the pyrimidine rings, then adding ammonia water to lead chloride to be substituted with aminogroups, and hydrolyzing under an acid condition to obtain a product, namely the 5-flucytosine. The preparation method has the beneficial effects that the methyl chloroacetate is adopted for substituting methyl fluoroacetate to be used as a synthetic raw material of the 5-flucytosine, so that the use of highly-toxic chemicals such as the methyl fluoroacetate is avoided; simultaneously, since the price of the methyl chloroacetate is much lower than the price of the methyl fluoroacetate, the production cost can be saved; by utilization of the synthetic route provided by the invention, the higher-purity 5-flucytosine can be prepared without need of complex aftertreatment steps; simultaneously, the preparation method has higher overall yield and obvious industrial value and is worthy of being promoted and used on a large scale.
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(2019/12/25)

Preparation method for 4-chloro-5-fluoro-2-methoxypyrimidine
The invention discloses a preparation method for 4-chloro-5-fluoro-2-methoxypyrimidine, and the preparation belongs to the technical field of an organic chemistry intermediate chemical process. The process summarily includes the following steps: adding an alkaline substance and a solvent to a reaction vessel, and stirring; adding phosgene, diphosgene or triphosgene as a chlorination reagent; and adding the 4-chloro-5-fluoro-2-methoxypyrimidine, and obtaining a target product with high yield and high purity through a simple post-treatment process after a detection reaction is completed. The preparation method is mild in process reaction condition, is simple in post-treatment, is low in cost, is high in yield which reaches 97-98.5%.
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Paragraph 0019; 0021-0047

(2019/01/06)

Preparation method of 2-methoxy-4-chloro-5-fluoropyrimidine
The invention discloses a preparation method of 2-methoxy-4-chloro-5-fluoropyrimidine, and belongs to the technical field of organic chemical intermediate chemical technological process. The preparation method comprises following steps: 2-methoxy-4-hydroxy-5-fluoropyrimidine, a solvent, and a catalyst are delivered into a container; phosgene, diphosgene, or triphosgene is taken as a chloridizing agent, heating reaction is carried out, after complete reaction, sample post-treatment is carried out so as to obtain a high-purity target product. The preparation method possesses following advantages: yield is relatively high; reaction conditions are mild; post-treatment is simple; cost is low; and industrialized production is convenient to realize.
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Paragraph 0023; 0024; 0025; 0026; 0027; 0028; 0029-0066

(2017/08/31)

Preparation method of 2-substituted-4-hydrazino-5-fluoropyrimidine
The invention belongs to the field of organic synthesis, discloses a new route and method for preparation of an agricultural herbicide florasulam intermediate, and in particular, relates to a preparation method of 2-substituted-4-hydrazino-5-fluoropyrimidine; 2-substituted-4-hydroxy-5-fluoropyrimidine as a raw material is chloridized under the action of a chlorination reagent, and then hydrazinolysis is carried out to obtain 2-substituted-4-hydrazino-5-fluoropyrimidine with the purity of 99% or more; the chlorination reagent is phosphorus oxychloride, and the solvent is benzenes, chloralkanes or nitriles. The preparation method has the advantages of simple preparation process, low dosage of phosphorus oxychloride, simple post-treatment method and cheap raw material; and the preparation method is suitable for large-scale industrialized production and has more commercial application value.
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Paragraph 0025; 0026; 0027

(2016/11/07)

Method for 5-fluorocytosine
A disclosed method for 5-fluorocytosine comprises a reaction shown in the specification, and the method is characterized by comprising the following steps: dissolving a compound shown as a formula IV in an organic solvent, adding triethylamine, dropwise adding phosphorus oxychloride at 40-100 DEG C, after dropwise adding is finished, keeping warm and stirring for reaction for 2-10 h, so as to obtain a compound shown as a formula III; adding the formula III compound into an organic solution of ammonia, and stirring at 40-80 DEG C for reacting for 2-8 h, so as to obtain a compound shown as a formula II; and adding the formula II compound into a hydrogen chloride organic solution, and stirring at 40-80 DEG C for reacting for 3-15 h, so as to obtain a compound shown as a formula I. The method realizes low-cost high-yield large-scale preparation of high-purity 5-fluorocytosine, and possesses substantial industrial value.
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Paragraph 0035; 0036; 0037

(2016/11/17)