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CN-121974833-A - Synthesis process of thermosensitive color-developing agent 3,3' -benzenesulfonyloxy diphenyl urea

CN121974833ACN 121974833 ACN121974833 ACN 121974833ACN-121974833-A

Abstract

The invention discloses a synthesis process of a thermosensitive developer 3,3' -benzenesulfonyloxy diphenyl urea, belonging to the technical field of organic synthesis. The process uses m-aminophenol, benzenesulfonyl chloride and triphosgene as raw materials, 1, 2-dichloroethane as a solvent and triethylamine as an acid-binding agent, adopts a one-pot method to construct two-step continuous reaction through sulfonylation and urea bond, and then obtains a target product through acidification, liquid separation, extraction, spin drying and methanol crystallization, and no intermediate is needed to be separated in the whole process. The method optimizes the parameters such as reaction temperature, feeding ratio and the like, solves the problems of complicated preparation process and low yield, has mild reaction conditions and convenient operation, adopts conventional analytical pure reagent as raw materials, has the yield of 72% -76% and the purity of more than 99.5%, has high raw material utilization rate, has good industrial application prospect, and can be widely used as a thermosensitive color developing agent.

Inventors

  • LI JIAZHENG
  • QU HONGCHUN
  • XING PENGFEI
  • DENG PAN

Assignees

  • 上海特锦供应链管理有限公司

Dates

Publication Date
20260505
Application Date
20260319

Claims (7)

  1. 1. A synthesis process of a thermosensitive color developing agent 3,3' -benzenesulfonyloxy diphenyl urea is characterized in that m-aminophenol, benzenesulfonyl chloride and triphosgene are used as raw materials, 1, 2-dichloroethane is used as a solvent, triethylamine is used as an acid binding agent, and the synthesis process adopts a one-pot method, and specifically comprises the following steps: Step 1, adding m-aminophenol, 1, 2-dichloroethane and triethylamine into a three-neck flask, placing a reaction system in a temperature environment of-5-10 ℃, slowly dropwise adding a1, 2-dichloroethane solution of benzenesulfonyl chloride in 1h through a constant-pressure dropping funnel, recovering the reaction system to room temperature after dropwise adding, and continuing to react for 1h until the reaction is complete; step 2, cooling the reaction system in the step 1 to 0 ℃, slowly dropwise adding a1, 2-dichloroethane solution of triphosgene through a constant pressure dropping funnel, and stirring for reaction for 1h until the reaction is finished after the dropwise adding is completed; step 3, adding 1mol/L hydrochloric acid into the reaction system of the step 2 to adjust the pH to 1-2, carrying out liquid separation treatment, collecting an organic phase, extracting a water phase with 1, 2-dichloroethane, and combining an extract and the organic phase; and 4, spin-drying the combined organic phases to remove the solvent, adding methanol into the spin-dried product, stirring for crystallization, and filtering to obtain a white solid, namely 3,3' -benzenesulfonyloxy diphenyl urea.
  2. 2. The process for synthesizing the thermosensitive developer 3,3' -benzenesulfonyloxy diphenyl urea according to claim 1, wherein the mass ratio of the intermediate aminophenol to the benzenesulfonyl chloride to the triethylamine in the step 1 is 100:162:138, the feed liquid ratio of the intermediate aminophenol to the 1, 2-dichloroethane initially added is 100g:500mL, and the feed liquid ratio of the benzenesulfonyl chloride to the 1, 2-dichloroethane dissolved therein is 162g:200mL.
  3. 3. The process for synthesizing the thermosensitive developer 3,3' -benzenesulfonyloxy diphenyl urea according to claim 1, wherein the feed liquid ratio of triphosgene to 1, 2-dichloroethane dissolved therein in the step 2 is 80g:300ml, and the feeding amount of triphosgene is 0.3eq based on m-aminophenol.
  4. 4. The process for synthesizing the thermosensitive developer 3,3' -benzenesulfonyloxy diphenyl urea according to claim 1, wherein the specific way of extracting the aqueous phase in the step 3 by using 1, 2-dichloroethane is that 1, 2-dichloroethane is extracted twice by proportioning the aqueous phase, and the 1, 2-dichloroethane consumption of each extraction is 100mL.
  5. 5. The synthesis process of the thermosensitive developer 3,3' -benzenesulfonyloxy diphenyl urea according to claim 1, wherein the spin drying process in the step 4 is characterized in that the spin drying process is carried out at a spin drying temperature of 40 ℃ and a vacuum degree of 0.09MPa, the spin drying process is stopped when no liquid drops fall in a distillate receiving bottle for 5min and the product in the spin drying bottle is a solid without flowing, the methanol addition amount is 10 times (g: mL) of the mass of the product after the spin drying, namely 10mL of methanol is added per 1g of solid product after the spin drying, the stirring crystallization temperature is 15 ℃, and the stirring time is 1h.
  6. 6. The synthesis process of the thermosensitive developer 3,3' -benzenesulfonyloxy diphenyl urea according to any one of claims 1-5, wherein m-aminophenol, benzenesulfonyl chloride, triphosgene and triethylamine are all analytically pure reagents, and the detection mode of the reaction completion in step 1 and step 2 is liquid chromatography-mass spectrometry.
  7. 7. The process for synthesizing the thermosensitive developer 3,3 '-benzenesulfonyloxy diphenyl urea according to claim 1, wherein the total yield of the synthesis process is 72% -76%, and the purity of the obtained 3,3' -benzenesulfonyloxy diphenyl urea is detected to be more than 99.5% by high performance liquid chromatography.

Description

Synthesis process of thermosensitive color-developing agent 3,3' -benzenesulfonyloxy diphenyl urea Technical Field The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis process of a thermosensitive color-developing agent 3,3' -benzenesulfonyloxy diphenyl urea. Background The 3,3' -benzenesulfonyloxy diphenyl urea belongs to a non-phenol color developing agent and is a core functional material in the field of thermal paper processing. Compared with the traditional color developer, the compound can obviously enhance the heat sensitivity and pressure sensitivity of the thermal paper, effectively optimize imaging image quality, improve image definition, simultaneously has excellent performance on key indexes such as luminous brightness, thermal stability and the like, has the characteristics of environmental protection and no toxicity, has wide application and popularization prospect as a new-generation green color developer, and can be widely applied to the fields of office printing, commercial retail, logistics medical treatment, cold chain monitoring, anti-counterfeiting safety, intelligent materials and the like. As shown in the chemical structural formula in FIG. 1, 3' -benzenesulfonyloxy diphenyl urea (C 25H20N2O7S2, molecular weight: 524.56) has a symmetrical structure, and the key of the synthesis is the construction of urea bonds. Currently, three common methods for industrially synthesizing urea bonds are mainly isocyanate method, triphosgene method and chloroformate method. Aiming at the symmetrical structural characteristic of 3,3' -benzenesulfonyloxy diphenyl urea, the triphosgene method has more remarkable advantages in terms of atom economy and synthesis efficiency, and is a more economic and efficient choice for synthesizing the compound. However, when 3,3' -benzenesulfonyloxy diphenyl urea is synthesized by a triphosgene method in the prior art, a stepwise synthesis method is specifically adopted, namely, after the sulfonylation reaction is completed, separation, purification and drying of intermediate are needed, urea bond construction reaction is carried out, and the problems of complicated preparation means, discrete reaction steps, complicated operation caused by the need of separation and purification of the intermediate, low raw material utilization rate, poor product yield and the like exist, so that the industrial production and large-scale application of the compound are severely limited. Therefore, developing a 3,3' -benzenesulfonyloxy diphenyl urea synthesis process with simplified process, convenient operation and high yield becomes a technical problem to be solved in the field. Disclosure of Invention The invention aims to provide a synthesis process of a thermosensitive developer 3,3' -benzenesulfonyloxy diphenyl urea, which solves the technical problems of complicated means, low yield and complex operation in the prior art for preparing the compound, realizes the efficient and simple synthesis of the compound, improves the utilization rate of raw materials and provides technical support for the industrialized application of the compound. In order to solve the technical problems, the invention is realized by the following technical scheme: in order to achieve the aim of the invention, the invention adopts the following technical scheme: A process for synthesizing 3,3' -benzenesulfonyloxy diphenyl urea as thermosensitive color developing agent features that m-aminophenol, benzenesulfonyl chloride and triphosgene are used as main raw materials, 1, 2-Dichloroethane (DCE) is used as solvent, triethylamine is used as acid-binding agent, and one-pot method is used to continuously perform two-step reaction without separating intermediate, and includes the following steps: Step1, sulfonylation reaction, namely adding m-aminophenol, 1, 2-dichloroethane and triethylamine into a three-neck flask, placing a reaction system in a low-temperature environment of-5-10 ℃, slowly dropwise adding 1, 2-dichloroethane solution of benzenesulfonyl chloride in 1h through a constant-pressure dropping funnel, returning the reaction system to room temperature after dropwise adding, continuing stirring for reaction for 1h, and detecting that the reaction is complete by adopting a liquid chromatography-mass spectrometry (LCMS); Wherein the mass ratio of the m-aminophenol to the benzene sulfonyl chloride to the triethylamine is 100:162:138, the feed liquid ratio of the m-aminophenol to the 1, 2-dichloroethane initially added is 100g:500mL, and the feed liquid ratio of the p-toluene sulfonyl chloride to the 1, 2-dichloroethane dissolved therein is 162g:200mL. Step 2, urea bond construction reaction, namely cooling the system subjected to sulfonylation reaction in the step 1 to 0 ℃, slowly dropwise adding 1, 2-dichloroethane solution of triphosgene through a constant pressure dropping funnel, wherein the feed liquid ratio of triphosgene to 1, 2-dichloroethane s