800 results about "Phosphoryl chloride" patented technology

The invention discloses a poly-phosphate flame retardant containing a DOPO side-chain structure and a preparation method thereof, belonging to the technical field of polymeric organic phosphorus flame retardant structures and the preparation method thereof. The flame retardant is characterized by comprising the following repeating unit structure: wherein n=5-50. The preparation method of the poly-phosphate flame retardant comprises the following steps of: reacting an intermediate I containing the DOPO structure with phosphorus oxychloride to obtain an intermediate II containing phosphorus oxychloride, and fusing and polymerizing the intermediate II and a bisphenol compound to obtain the poly-phosphate flame retardant containing the DOPO side-chain structure. The preparation method is simple, and through adjusting Ar categories and ratios, the phosphorus content can be controlled at 11.5-15.5% and the sulfur content can be controlled at 0-5.9%. The flame retardant has the characteristics of favorable thermal stability, high decomposition temperature, favorable char-forming property, and the like, and can be used for flame retardance modification of materials, such as polyester, polyamide, polycarbonate and blends thereof, and the like, with higher processing temperature.

The invention has supplied phosphor containing shown as follows and its preparing method. Use phosphorus oxychloride and diatomic alcohol as the raw material to prepare phosphoryl chloride compound; meanwhile, use poly-polysiloxane containing amino and hydroxyl siloxane with low molecular weight to generate poly-polysiloxane containing amino; then dissolve the two compounds generated in organic solvent synthesize to be poly-polysiloxane containing p with temperaturing rising. The invention can be used as flame retardant which contains several elements like Si, P and N for polyolefin, polyacrylic acid, ABS, nylon, cellulose or polyvinyl alcohol. R1 and R2 are separately chosen from CH3 or C6H5, R3 from (CH2)r or (CH2)rNH(CH2)q, R4 and R5 seperately from H, CH3 or C2H5.

The invention provides a preparation method of clindamycin phosphate; the method of the invention includes the following processes: muriatic acid clindamycin and a solid light (C[3]Cl[6]O[3]) carry out chlorination reaction in a chloroform solvent under the temperature of 50 to 80 DEG C; then are alcoholized and ketonized; finally under the co-catalysis of naphthyridine and triethylamine, the muriatic acid clindamycin and phosphorus oxychloride are esterified, hydrolyzed, absorbed and crystallized in an acetone solvent to obtain the clindamycin phosphate. The solid light is adopted to take part in the chlorination reaction in the reaction system of the invention, thus lightening the pressure of environment protection; simultaneously the content of epiclindamycin in the finished product is reduced; moreover, partial naphthyridine is replaced by the triethylamine, thus reducing the cost and improving the yield to a large extent.

The present invention relates to methods for preparing substituted 3-cyanoquinolines and intermediates obtained by the methods of the present invention. The methods of the invention comprise reacting an N-aryl-2-propanimide with phosphoryl chloride to produce the substituted 3-cyanoquinolines. The methods further comprise reacting arylamines, orthoformates and active methylenes to produce the N-aryl-2-propenamide.

The invention relates to a preparation method for flame retardant bisphenol A bi(diphenyl phosphate). The preparation method comprises the following steps: taking phosphorus oxychloride, bisphenol A and phenol as raw materials, adopting anhydrous zinc chloride or anhydrous aluminum chloride as a main catalyst, and adopting anhydrous calcium chloride or calcium phosphate as a promoter; adding the phosphorus oxychloride, the main catalyst and the promoter into a reactor for intensive stirring, when the materials are heated up to 73 to 78 DEG C, continuously adding bisphenol A, after the addition of bisphenol A is completed within 2.5 to 3 hours, heating up to and maintaining the temperature of 110 to 115 DEG C, and continuing the reaction for 1.5 to 2 hours; leaking out excessive phosphorus oxychloride under the normal and reduced pressure; and cooling down the intermediate product to 100 DEG C, continuous dropping phenol into the intermediate product, heating up to 140 DEG C 2 hours later, carrying out the reaction for 3 to 4 hours, monitoring the content of phenol through the liquid chromatography, and complementing phenol till the phenol content in the crude product is less than 0.5 percent. The yield reaches 98 percent; the content of triphenyl phosphate is less than 1.5 percent; and the acid number is 0.03mgKOH/g.

The invention relates to an improved preparation method of an oligomeric phosphate ester, and is characterized in that the method comprises the steps of: obtaining dichloro-monoalkyl phosphate ester monomer through the reaction of phosphorus oxychloride and a monohydric alcohol performing the polymerization of the dichloro-monoalkyl phosphate ester monomer with a dihydric alcohol, and blocking end with a monohydric alcohol. Compared with the prior art, the inventive preparation method has the advantages of easily accessible raw materials, low corrosiveness, low cost (reducing cost by about 50%), no dangerous chemicals as raw materials, good safety, synthesis under relatively low temperature and low pressure, simple process, high production safety factor, simple equipment and operation, and no pollution in production process. The produced hydrogen chloride during reaction can be directly used in production of polyaluminum chloride.

The invention relates to a method for preparing the designed herbicide pretilachlor intermediate chloride ether. Under the action of organic amine catalyst, the chloride ether can be obtained by ethylene glycol monopropyl ether and bis (trichloromethyl) hydroxyphenyl in the organic solvent through the following chemical equation: HOC2H4OC3H7+Cl3COCOOCCl3 arrow ClC2H4OC3H7+CO2+HCl. The method replaces the traditional chlorination reagent with the bis (trichloromethyl) hydroxyphenyl, such as, thionly chloride, phosphorus oxychloride and hydrogen chloride, etc., and the potential safety hazard can be eliminated from the process source by using the novel chlorination reagent. Simultaneously, the emissions of pollutants are greatly reduced, and the method is a cleaning process with mild reaction conditions, safe and reliable operating process and high product yield, and has good industrialization implementation value and social economic benefits.

The invention discloses a method for synthesizing highly-pure bendamustine hydrochloride, which comprises the following steps: taking [1-methy-2(4'-ethyl butyrate)-5-amino]-1H-benzimidazole as a raw material; and orderly reacting the [1-methy-2(4'-ethyl butyrate)-5-amino]-1H-benzimidazole with ethylene oxide and phosphorus oxychloride through the four steps of substitution, hydrolysis, salification and refinement so as to produce the bendamustine hydrochloride. The method in the invention is mild in condition, simple in operation, short in synthesis period and suitable for scaled-up industrial production; and the purity of the synthesized bendamustine hydrochloride is over 99.5 percent, while monomeric impurity is below 0.1 percent, which meet the quality standards of raw material medicament.

The invention relates to a bromine-containing pentaerythritol phosphoester fire retardant and a preparation method thereof. The bromine-containing pentaerythritol phosphoester fire retardant is pentaerythritol double-spiro phosphoryl double-tribromo neopentyl alcohol ester. The preparation method of the novel bromine-containing pentaerythritol phosphoester comprises the following steps of: 1, reacting pentaerythritol with phosphorus oxychloride to generate an intermediate pentaerythritol double-spiro double-phosphorus oxychloride; and 2, reacting the pentaerythritol double-spiro phosphorus oxychloride with tribromo neopentyl alcohol to generate the pentaerythritol double-spiro phosphoryl double-tribromo neopentyl alcohol ester, wherein in the reaction, quaternary ammonium salt cation ionic liquid serves as a solvent and a catalyst. The invention discloses a new synthesis method of the bromine-containing pentaerythritol phosphoester fire retardant. The ionic liquid serves as the solvent, so the synthesis yield is improved; and a phosphorus-bromine synergistic flame retardant technique is adopted in the design of a molecular structure, so the anti-flaming efficiency of the flame retardant for high molecular materials is improved.

The invention discloses a polymeric phosphorus-containing flame retardant with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as a lateral group and a preparation method thereof. The preparation method is characterized by comprising the following steps: placing aromatic dihydric phenol and pentaerythritol diphosphate diphosphoryl chloride (or bromine) which are modified by the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in an anhydrous acetonitrile solvent based on reaction mol ratio, heating the obtained mixture to 80 DEG C in an inert atmosphere, agitating and reacting until no halogen hydride is released, cooling the obtained mixture to the room temperature, and depressurizing the mixture to remove the solvent. The obtained product has high phosphorus content, very good expansibility and char formation, and good flame retardation effect. When flame retardation is performed on epoxy resin, the limiting oxygen index of the obtained product is greatly improved and the vertical burning scale reaches V-0 level; and the polymeric phosphorus-containing flame retardant has the advantage of overcoming the disadvantages of low thermal decomposition temperature, poor compatibility with polymer matrix and easy migration in the existing micromolecular phosphorus flame retardants. The preparation method has the advantages of being simple and feasible, using no catalyst and simple post-treatment process.

Preparation method and application of a phenyl phosphate flame retardant containing DOPO. The method is as below: under the action of methanol, reacting 4-amino phenol, 2-hydroxy benzaldehyde, DOPO and formaldehyde in one pot to synthesize an intermediate I; reacting phenyl dichlorophosphate and resorcinol to synthesize an intermediate II (resorcinol bisphenoxyl phosphoryl chloride); and reacting the intermediate I and intermediate II to obtain a white solid which is the phenyl phosphate flame retardant containing DOPO. The initial decomposition temperature of the flame retardant was about 363, and the rate of residual carbon was 49% at 468, 800, and the flame retardant had good thermal stability, high residual carbon ratio and good flame retardant effect, which can be used for the non halogen flame retardant of polypropylene and ABS.

The present invention discloses a preparation process of phosphonitrogen series expanded fire-retarding agent and fire-retarding agent prepared according to said preparation process. Said preparation process includes the following steps: making polybasic alcohol be reacted with phosphorus oxychloride, making the obtained product undergo the processes of hydrolysis and solution pH value regulation, then making said product be reacted with cyanurotriamide, the described polybasic alcohol includes pentaerythritol and dipentaerythritol, then using surfactant to make surface modification treatment so as to obtain the invented fire-retarding agent.

The invention discloses an anti-mud type phosphate modified polycarboxylate superplasticizer and a preparation method thereof. The method specifically comprises the following steps: performing oxidation-reduction free radical polymerization reaction on unsaturated carboxylic acid micro-monomer and unsaturated polyether macro-monomer in the presence of an initiator, a reducing agent and a chain transfer agent, thereby acquiring a carboxyl-containing polycarboxylate superplasticizer prepolymer; with diphenyl phosphoryl chloride, modifying the carboxyl-containing polycarboxylate superplasticizer prepolymer partially, thereby acquiring a phosphate based copolymerization product; after completing the reaction, regulating the pH value to 6-7 and adding water, thereby acquiring the polycarboxylate superplasticizer. According to the invention, the side chain of the polycarboxylate superplasticizer is modified into a phosphate group containing two benzene rings and the phosphoric acid functional group enters into the carminate element of the polycarboxylate superplasticizer, so that the sulfate radical resisting capacity and anti-mud capacity of the polycarboxylate superplasticizer are promoted. The introduction of the benzene rings can greatly increase the physical size of the side chain of the polycarboxylate superplasticizer and the polycarboxylate superplasticizer is unlikely to be inserted into the layered structure of clay, so that the anti-mud effect can be achieved and the intrinsic function of the polycarboxylate superplasticizer is not influenced.

The invention provides a method for preparing bisphenol A bi-(diphenyl phosphate). The method is characterized in that the proper amount of bisphenol A and phosphorus oxychloride is added in a reactor, and subjected to heating and stirring until bisphenol A is completely dissolved, and dissolved materials are obtained; the proper amount of Lewis acid and phosphorus oxychloride is added in a reactor provided with a chlorine hydride absorption device and subjected to quick heating, the dissolved materials are added in the reactor, the excessive phosphorus oxychloride is distilled off after the reaction finishes, and the proper amount of phenol is added, the temperature is adjusted until the reaction finishes, and the finished product is obtained after washing and debenzolization. The product prepared by the process of the invention has the advantages of having good product quality, lowering labor intensity, improving working environment and having better economic and social benefits.

The invention discloses a flame-retardant lithium ion battery electrolyte and a method for preparing the same and relates to a battery electrolyte. The electrolyte has the characteristic of flame retardance and complete non-combustion and is well compatible with an electrode material, and the wettability of a diaphragm can be improved. The flame-retardant lithium ion battery electrolyte comprises 5 to 20 percent of lithium salt, 60 to 90 percent of solvent and 1 to 20 percent of alkenyl phosphamide. The method comprises the following steps of: reacting dialkoxyl phosphoryl chloride and alkenyl-containing secondary amine, or hydro-diphosphite, the alkenyl-containing secondary amine, carbon tetrachloride and alkali, which are taken as raw materials, in an organic solvent to obtain an alkenyl phosphamide compound; and preparing the alkenyl phosphamide compound, the lithium salt and the solvent to obtain the flame-retardant lithium ion battery electrolyte.

The invention relates to a phosphorus-nitrogen-silicon intumescent flame retardant containing a triazine ring and a cage structure and a synthesis method of the intumescent flame retardant. The synthesis method comprises the steps as follows: a solvent is added to a container, phosphorus oxychloride is added and stirred to be dispersed, PEPA (1-oxy phospha-4-(hydroxymethyl)-2,6,7-trioxabicyclo[2.2.2]octane) and an acid-binding agent are dropwise added step by step, and a PEPA-containing unitary substituent is obtained; substances with diamine or dihydric alcohol are added to the other container and mixed with the solvent and the acid-binding agent, the PEPA-containing unitary substituent is slowly dropwise added, and a phosphorous-containing diamine intermediate is obtained after separation; the solvent is added to a container provided with a reflux condenser and the like, cyanuric chloride is added and stirred to be dispersed, an amino silane coupling agent and the acid-binding agent are dropwise added step by step, and a silicon-containing unitary substituent is obtained; the mixture of the phosphorous-containing diamine intermediate and the acid-binding agent is slowly dropwise added, cooling, washing and drying are performed, and a powdery solid, namely, the phosphorus-nitrogen-silicon intumescent flame retardant containing the triazine ring and the cage structure, is obtained. The phosphorus-nitrogen-silicon intumescent flame retardant has the advantages that the flame retardant has certain polymerization degree, high molecular weight, higher charcoal forming amount and better thermal stability, the proportion of acid sources, carbon sources and gas sources in molecular structures is relatively proper and the like.

The invention discloses reactive phosphorus triazine flame retardant for dyeing, and a preparation method and application thereof, which belong to the technical field of flame retardants and relate to flame retardant for cotton. A molecular structure of the reactive phosphorus triazine flame retardant for dyeing is OPO3OCLO3OO3PO. The preparation method includes: mixing pentaerythritol with dioxane under protection of inert gases, dropwise adding phosphorus oxychloride at 80 DEG C for two hours, adding two to three drops of triethylamine, allowing for reaction for 4-10 hours, cooling, filtering, vacuum-drying to obtain PEPA after rinsing; and mixing cyanuric chloride with reaction solvent, adjusting the temperature to 10-20DEG C, initially dropwise adding the PEPA and acid-binding agent, allowing for continuous reaction for 6 hours, dropwise adding again the PEPA and the acid-binding agent, allowing for reaction for 6 hours, adding precipitant for precipitation after cooling, filtering, rinsing, and drying to obtain the fished product. The preparation method is simple, the prepared flame retardant has a carbon source, an acid source and a gas source integrated and is higher in thermal stability and better in carbon forming performance, and the PEPA and the triazine structure are complemented while both being given to full play to the advantages.

The present invention provides one new kind of chiral organic phosphoric acid catalyst characterizing biaxial chirality and its preparation process. The chiral organic phosphoric acid catalyst is prepared with chiral binaphthol or its derivative, and through protection with methoxymethyl group, alkylation, iodination, coupling with boric acid intermediate to obtain binaphthol derivative, the deprotection of the binaphthol derivative and reaction with phosphorus oxychloride to obtain the organic phosphoric acid compound. The chiral catalyst preparing process is simple, and the chiral catalyst is applied in catalyzing asymmetric hydrogenation reaction of quinoline compounds and has high efficiency, and high selectivity.

The invention provides an aromatic polymer sulfonamide. The above polymer adopts an aromatic polymer as a main chain, and the side chain of the polymer contains a sulfonamide group. The sulfonamide group is hydrophobic, can dissociate at a high temperature to provide protons, and cross-links with an acyl chloride group, a sulfonyl chloride group and a phosphoryl chloride group, so the aromatic polymer sulfonamide has the advantages of good barrier, good conductivity and good mechanical strength as a film material, and has good application prospects in fields of fuel batteries, flow batteries, electrodialysis and solid acid catalysts.

The invention discloses a synthesizing method of adenine represented by a formula (I). The method comprises steps that: (1) acetyl hypoxanthine represented by a formula (III) and excess phosphorus oxychloride are subject to a chlorination reaction under the catalyzing of N,N-dimethyl aniline; the reaction is sufficiently carried out, and then 6-chloropurine represented by a formula (II) is obtained after processing; (2) in an autoclave, ammonia gas is delivered to an aqueous solution of 6-chloropurine until saturated; the autoclave is sealed, and a temperature in the autoclave is increased to120 to 140 DEG C; a reaction is processed until the materials are completely reacted; the pH value of the reaction liquid is regulated to 7-8; the reaction liquid is cooled, an adenine crude product is precipitated; the adenine crude product is refined by using water, and is processed through active carbon decoloration, such that adenine represented by the formula (I) is obtained. The synthesizing method provided by the invention is advantaged in high production efficiency, high reaction yield, good product quality, low three-waste rate, and low production cost.

The invention relates to a hexaphenyl phosphate ester melamine salt fire retardant and a method for preparing the same. Based on the molar ratio, the reaction ratio of diphenyl phosphorus oxychloride to melamine is (3.0-3.6):1.0, and the diphenyl phosphorus oxychloride comprises components of phenol, phosphorus oxychloride and anhydrous magnesium chloride in a ratio of (2.0-2.5):(1.0-1.4):(0.01-0.03). The preparation method comprises the following steps of: adding phosphorus oxychloride, anhydrous magnesium chloride and phenol respectively, performing continuous stirring reflux during reaction, and performing vacuum distillation after the reaction to obtain diphenyl phosphorus oxychloride; and adding the diphenyl phosphorus oxychloride and melamine, performing stirring reflux, and after the reaction, cooling the obtained product in an ice bath, and performing suction filtration, water washing and drying on the product to obtain the hexaphenyl phosphate ester melamine salt. The hexaphenyl phosphate ester melamine salt fire retardant prepared by the method has the advantages of low toxicity, less smoke, harmlessness, high efficiency, environmental friendliness and the like and leads the development trend of intumescent fire retardants in the future.

The invention discloses the inflatable fire retarding agent, comprising the following characters: using the amylophosphatase melamine salt as essential component, which is made by chlorinated amylophosphatase, made by amidon and phosphorus oxytrichloride, and melamine-formaldehyde prepolymer made by melamine and cavaform. The invention provides the new inflatable fire retarding agent including the charcoal source, acid source, gas source. The product is encapsulated to improve the water resistance and stability of fire retarding agent.

The invention relates to a method for preparing rivastigmine hydrogen and tartrate thereof, which comprises the following steps: taking metamethoxyacetophenone as an initial raw material, and obtaining 1-(3-methoxyphenyl)ethanol by the reduction; then performing the chlorination to obtain 1-(chloroethyl)-3-methoxyphenyl; then reacting the1-(chloroethyl)-3-methoxyphenyl with dimethylamine hydrochloride to obtain 1-(3-methoxyphenyl)-N, N-dimethylethanamine; demethylating the reaction product to obtain 3-[1-(dimethylamino)ethyl]phenol; then performing salt formation resolution with (s)-(+)-camphor-10-sulfonic acid, recrystallizing, and dissociating to obtain (s)-3-[1-(dimethylamino)ethyl]phenol; then taking ethylamine as a raw material to react with ethyl formate to obtain formylethylamine; then reacting the formylethylamine with phosphorus oxychloride to obtain an imine intermediate; reducing the imine intermediate by sodium borohydride to obtain ethyl methyl amine; then reacting the ethyl methyl amine with triphosgene to obtain N-methyl-N-ethylformyl chloride; and finally using (s)-3-[1-dimethylamino)ethyl]phenol to condensate with the N-methyl-N-ethylformyl chloride, and then performing salt formation with levotartaric acid to obtain the rivastigmine hydrogen tartrate. The method has the advantages of easily-obtained raw materials, simple and convenient operation, low cost, high yield and small pollution, and is a brandnew synthesis route at present.

The invention relates to a symmetrical double-rhodamine B fluorescent probe for detecting a mercury ion and a preparation method of the fluorescent probe. The structural formula of the symmetrical double-rhodamine B fluorescent probe RBSRB (rhodamine B-symmetrical-rhodamine B) is as shown in the specification. The preparation method comprises the following steps: adding rhodamine B and phosphorus oxychloride into a solvent for reflux reaction for 20-24h at 85-90 DEG C, obtaining rhodamine B acyl chloride, dissolving rhodamine B acyl chloride and 2-bromine ethylamine in the solvent, stirring for reaction for one night at room temperature, purifying to obtain rhodamine B acyl-2-bromine ethylamine, adding rhodamine B acyl-2-bromine ethylamine and sodium sulfide into the solvent for reflux reaction for 5-8h at 80-85 DEG C, and purifying to obtain the fluorescent probe. The fluorescent probe is symmetrical double-rhodamine B amide connected by a sulphur atom; only alcohol under 1% is introduced as a cosolvent during an experiment; the fluorescent probe is high in selectivity, and has high selectivity to the mercury ion; other common ions do not interfere with the fluorescent probe obviously; and the fluorescent probe has an application prospect in bioluminescence imaging.

The preparation process of fire retardant resorcinol tetraphenyl diphosphate includes the first step of the reaction between phenol and phosphorus oxychloride in the presence of Lewis acid catalyst and under heating to produce triphenyl phosphate ester; and second step of ester interchange reaction between triphenyl phosphate ester and resorcinol in the conditions of catalysis, heating and decompression to obtain resorcinol tetraphenyl diphosphate. The reaction temperature is 80-260 deg.c; the catalyst for the first step is Lewis acid catalyst; and the catalyst for the second step is Lewis acid catalyst or alkali catalyst in the amount of 0.05-3 wt% of resorcinol. The acid catalyst is selected from MgCl2, ZnCl2, AlCl3 and TiCl4 and the alkali catalyst is selected from NaOH, KOH, Na2CO3, K2CO3 and sodium phenate. The present invention has the advantages of short reaction period, low power consumption, high product yield and less environmental pollution.

The invention relates to a halogen-free phosphate fire retardant used for engineering plastics and a method for producing the same, belonging to the engineering plastic fire retardant and the method for synthesizing the engineering plastic fire retardant technical field. The chemical name of the fire retardant is hydroquinone double phenyl bisphosphate oligomer, and the chemical structural formula is shown on the bottom right. The method comprises the following processing steps: firstly, the method adopts hydroquinone and phosphorus oxychloride as raw materials and a lewis acid as a catalyst for heating reaction; and secondly, the reaction mixture is heated up and dripped with phenol for reaction by taking the lewis acid as the catalyst. The production method has sufficient supply of the raw materials and simple reaction conditions, can reduce the manufacturing cost, and makes products have obvious price advantage; and simultaneously the material has the characteristics of zero halogen, low smoke, low toxity, low corrosiveness, high heat distortion temperature, good fire resistance, good processability, capability of being recycled, etc., and can be widely used as the fire retardant of various engineering plastics.

The invention relates to a chemical synthesis agent and a preparation method thereof and provides a reactive epoxy resin flame-retardant curing agent containing phosphorus and nitrogen and a preparation method thereof. Raw materials for preparation of the curing agent comprise pentaerythritol, phosphorus oxychloride and 4,4-diamino diphenyl sulfone (DDS). The preparation method for the curing agent comprises the following two steps: step 1, reacting pentaerythritol (PER) with phosphorus oxychloride (POCl3) under certain conditions so as to produce a phosphorus-containing intermediate, i.e., pentaerythritol bisphosphorate diphosphoryl choloride (SPDPC); and step 2, subjecting SPDPC and DDS to a stirring reaction for a certain period of time under the condition of introduction of inert gas and subjecting a product to filtration, washing, drying and the like so as to obtain a white powder which is a phosphorus-nitrogen intumescent flame retardant. The reactive epoxy resin flame-retardant curing agent has high heat stability, expansibility and char yield and can be used as a flame retardation additive to a plurality of polymer materials so as to improve the flame retardant property of the polymer materials. The preparation method provided by the invention has the advantages of simple production conditions, high product purity, high yield and simple and convenient post treatment.

The invention relates to a preparation method of 4-chloropyrrolo[2,3-d]pyrimidine.The method includes the following steps of obtaining 2-cyano-3-(1,3-dioxolan)ethyl propionate after 2-bromomethyl-1,3-dioxolane and ethyl cyanoacetate which are used as the raw materials react with alkaline matter as the catalyst; conducting cyclization on obtained 2-cyano-3-(1,3-dioxolan)ethyl propionate and formamidine acetate with alkaline matter as the catalyst, and adding hydrochloric acid for hydrolysis cyclization to obtain pyrrolo[2,3-d]pyrimidin-4-ol; making obtained pyrrolo[2,3-d]pyrimidin-4-ol react with phosphorus oxychloride to obtain 4-chloropyrrolo[2,3-d]pyrimidine.The method for preparing 4-chloropyrrolo[2,3-d]pyrimidine is simple in technological process, the requirement for production conditions is low, the product is easy to purify and high in yield, and the production efficiency and product quality of 4-chloropyrrolo[2,3-d]pyrimidine are remarkably improved.