CN101440048B - Method for preparing diphenylmethane dicarbamic acid ester in double solvent system - Google Patents
Method for preparing diphenylmethane dicarbamic acid ester in double solvent system Download PDFInfo
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- CN101440048B CN101440048B CN2007101779272A CN200710177927A CN101440048B CN 101440048 B CN101440048 B CN 101440048B CN 2007101779272 A CN2007101779272 A CN 2007101779272A CN 200710177927 A CN200710177927 A CN 200710177927A CN 101440048 B CN101440048 B CN 101440048B
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Abstract
The invention relates to a method for synthesizing diphenylmethane diurethane through catalysis of liquid acid in a composite solvent system, in particular for synthesizing 4,4,-diphenylmethane diurethane. In the composite component solvent system, a phenyl carbamate reagent and a methylenation reagent are catalyzed and condensed through liquid organic acid; a composite component solvent can well promote catalytic activity of the liquid acid; and in the process of synthesizing the diphenylmethane diurethane by one-step reaction, the conversion rate of phenyl carbamate as a raw material reaches 97.46 percent, the yield of diphenylmethane diurethane is 86.93 percent, the selectivity of 4,4,- diphenylmethane diurethane in a product can reach 91.56 percent, and only a few byproducts are generated. After the reaction is completed, an MDC product can be separated through filtering and washing; the solvent can be recycled; after recycling, the yield of the MDC can still reach over 80 percent; and the method has good effect and does not cause the waste of the raw materials and the solvent.
Description
Technical field
The present invention relates to the method for liquid acid catalysis synthesizing diphenyl methane diamino formic ether in the double solvents system.
Background technology
'-diphenylmethane diisocyanate (MDI) is the important source material of synthesis of polyurethane, also be used for synthetic metal cakingagent, glass fibre, colo(u)r coating and various leatheroid, be widely used in fields such as building, automobile, boats and ships, aviation, electronics, shoemaking and daily necessities, demand both domestic and external in recent years increases rapidly.Diphenyl methane diamino formic ether (MDC) is the important intermediate of the synthetic MDI of non-phosgene.Therefore a kind of method that the synthetic MDC of cleaning of using value is arranged is provided, and is pressing for of modern industry development, will produce good social benefit.
Phenyl urethan and the condensation of methylenation reagent generate the reaction of diphenyl methane diamino formic ether, and open reported method Central Asia methylating reagent has formalin (formalin), trioxymethylene, Paraformaldehyde 96 and Methylal(dimethoxymethane) etc.Catalyzer mainly is divided into solid acid catalyst and liquid acid catalyst two big classes.Solid catalyst mainly contains ion exchange resin (US4282370, US4243815), heteropoly compound (JP57149260, JP57114563, JP81167656), zeolite catalyst (US5241119), clay pit and metal phosphate, Lewis acid or immobilized Lewis acid (US5079383, US4202986) and metal oxide and load SO thereof
4 2-Type solid super-strong acid (JP5867660, JP5862151) etc.Liquid acid catalyst mainly contains inorganic liquid acid such as sulfuric acid, hydrochloric acid, phosphoric acid and mixing acid.JP01135758 and JP01261358 have announced in water solvent 96% the sulphuric acid catalysis N-phenylurethane and the condensation reaction of formaldehyde, and the transformation efficiency of MPC (R=Et) is 98.4%, and the total recovery of dimer MDC is 73%.JP04202172 discloses a kind of method with the mixed acid catalyst synthesizing diphenyl methane diamino formic ether, with H
2SO
4, H
3PO
4And HCO
2The mixing acid of H is catalyzer, and water is solvent, and the transformation efficiency of MPC (R=Et) is 92%, and the selectivity of MDC (R=Et) is 88%.Be catalyzer with the mineral acid among the CN1775354, add inorganic acid salt, in the aqueous solution, react as auxiliary agent, the MDC yield reaches 91%, selectivity is 96%, but having of hydrochloride may be introduced chlorion in product, and the performance of final product MDI is had certain influence.
In aforesaid method, the condensation reaction of solid acid catalysis phenyl urethan and methylenation reagent requires to be reflected in the anhydrous system to carry out.Because solid acid catalyst is met the easy inactivation of water electrode, must adopt anhydrous methylating reagent, need in band toxic organic solvent such as oil of mirbane, react usually, need separate solvent with methods such as distillations with product, and reaction efficiency is low and cost is higher; Should reaction itself produce by product-water in addition, need to use the influence of elimination water such as band aqua, to guarantee the activity of solid acid catalyst; Diphenyl methane diamino formic ether particularly 4,4 '-productive rate of diphenyl methane diamino formic ether has only 30～50%, and the product complexity, has by products such as three nuclears, multinuclear oligopolymer and N-benzyl compounds to generate in a large number.Thereby to realize that solid acid catalysis synthesizes the large-scale industrial production of MDC, further further investigation awaits.Liquid acid catalyst adopts water to make solvent mostly, and catalyst liquid acid and methylenation reagent formaldehyde is at water, and raw material MPC is soluble in water and form new organic liquid phase, and liquid-liquid two phase reaction resistance to mass transfer is bigger, and reaction efficiency is lower.As solvent, unreacted raw material MPC was mixed in product MDC liquid acid catalyst after reaction was finished, and was difficult to the Separation and Recovery utilization with water.Therefore, these class methods are not suitable for producing the raw material MDC of the pure MDI of preparation, because by product is more, the separation and purification difficulty also is not suitable for large-scale industrial production.
Summary of the invention
For addressing the above problem, the present invention propose a kind of in the double solvents system method of liquid acid catalysis synthesizing diphenyl methane diamino formic ether.With the liquid mineral acid is catalyzer, the condensation reaction of catalysis phenyl urethan and methylenation reagent in the plural components solvent that organic solvent-water is formed.
In the method for the invention, the plural components solvent system is the plural components solution that organic solvent-water is formed, liquid mineral acid can keep good proton activity in this solvent, and organic solvent can increase the mutual solubility of organic liquid phase and water in the raw material, reduced the reaction resistance between liquid-liquid two-phase, played good promoter action for this two-phase contact reacts.
The method for preparing diphenyl methane diamino formic ether in the double solvents system of the present invention is:
Benzene feedstock carbamate, liquid mineral acid catalyzer, plural components solvent are joined in the reactor, stirring is warmed up to 50 ℃, dropwise add methylenation reagent, kept 0～1 hour after being warmed up to 60～150 ℃ of temperature of reaction, add methylenation reagent, reaction system is carried out condensation reaction and is stopped stirring heating after 1～10 hour under normal pressure, leave standstill cool to room temperature, and filtration, washing, drying obtain the solid product diphenyl methane diamino formic ether.
The mol ratio of described reaction system Central Asia methylating reagent and phenyl urethan is 1: 1～4; Described phenyl urethan is methyl phenyl carbamate, N-phenylurethane, carbaniloyl n-propyl or the positive butyl ester of carbaniloyl; Described methylenation reagent is formaldehyde, trioxymethylene or Paraformaldehyde 96 etc.
Employed plural components solvent is the plural components solution system that organic solvent-water is formed among the present invention, the consumption of plural components solvent is 3～15 times of quality of phenyl urethan in reaction system, preferably 5～10 times, wherein to account for the massfraction of plural components solvent be 5%～30% to organic solvent.
Described organic solvent is hydrophilic organic solvent, can form solution with water, mainly comprises water miscible aliphatic carboxylic acid, is selected from one or both the mixture in formic acid, acetate, propionic acid, butyric acid, the oxalic acid etc.
The mol ratio of liquid mineral acid and phenyl urethan is 1～8: 1 in the described reaction system; Liquid mineral acid is selected from the mixing acid of one or both mineral acids in sulfuric acid, hydrochloric acid, phosphoric acid, the nitric acid etc., and the preferred liquid inorganic acid catalyst is a sulfuric acid.
Method of the present invention is carried out under 60～150 ℃ temperature of reaction.System temperature is low excessively, reaction can not carry out or speed of reaction very low, easily generate intermediate by-products such as a large amount of N-benzyl compounds.If temperature of reaction is too high, 2,4 '-diphenyl methane diamino formic ether, 2, the easily a large amount of generations of by product such as 2 '-diphenyl methane diamino formic ether and three nuclears, four nuclears and the many phenyl urethans of multinuclear polymethylene.
Reaction system of the present invention condensation under normal pressure is reacted, reactive mode is an intermittent reaction, methylenation reagent once adds or multiple fractionation adds, the mol ratio of methylenation reagent and phenyl urethan is 1: 1～4, reaction times is 1～10 hour, with factors vary such as feed way, temperature of reaction, raw material consumption and alr modes, more excellent scope is 1.5～6 hours.
The present invention carries out in the plural components solvent system, phenyl urethan and methylenation reagent are through the liquid mineral acid catalyzing and condensing, the plural components solvent can promote the catalytic activity of liquid acid well, in single step reaction synthesizing diphenyl methane diamino formic ether process, the transformation efficiency of benzene feedstock carbamate has reached 97.46%, the yield of diphenyl methane diamino formic ether is 86.93%, in the product 4, the selectivity of 4 '-diphenyl methane diamino formic ether can reach 91.56%, has only minor by-products to generate.Because the organic solvent in this plural components solvent has certain solubleness to MPC, and very faint to the dissolving power of product MDC, unreacted raw material MPC major part was stayed in the plural components solvent after reaction was finished, and product MDC separates out fully.Reaction finish after-filtration separate get final product solid product, simple to operate; The filtrate recycling use, circulation back MDC yield still can reach more than 80%, and is respond well, can not cause the waste of raw material and solvent.
Embodiment
Embodiment 1
Thermometer will be housed, add 7.55g methyl phenyl carbamate (MPC) in the 100ml there-necked flask of condensing reflux pipe and constant pressure funnel, mass concentration be 96% sulfuric acid 14ml (with the mol ratio of MPC be 5: 1), mass concentration is 15% acetic acid aqueous solution 50ml (is about MPC quality 7 times), the magnetic agitation heating, when being warmed up to 50 ℃ with constant pressure funnel dropwise drip mass concentration be 37% formalin 2.0ml (with the mol ratio of MPC be 1: 2), be warmed up to 95 ℃ after dripping formaldehyde, add the 0.2ml formalin after 1 hour again, normal pressure reacted 3 hours down, stop heating, leave standstill cool to room temperature, filter, washing, drying obtains solid product and mixes filtrate.With gained solid and filtrate through efficient liquid phase chromatographic analysis, the result is: the transformation efficiency of methyl phenyl carbamate is 97.46%, the yield of diphenyl methane diamino acid methyl ester is 86.93%, wherein 4,4 '-diphenyl methane diamino acid methyl ester accounts for 91.56%, 2,4 '-diphenyl methane diamino acid methyl ester productive rate is 3.7%, and all the other are three nuclears, tetranucleate oligomer by product.Detect 0.1792gMPC in the filtrate, account for 89% of unreacting material total amount.
Embodiment 2
Gained filtrate 48ml behind the separate solid among the embodiment 1 is done catalyzer and solvent, join in the there-necked flask of 100ml with 6.04g MPC, stirring is warmed up to 50 ℃, it is 37% formalin 1.5ml that constant pressure funnel dropwise drips mass concentration, is warmed up to 95 ℃ after dripping formaldehyde, adds the 0.15ml formalin again after 1 hour, normal pressure reacted 3 hours down, stop heating, leave standstill cool to room temperature, filtration, washing, drying obtain solid product.With gained solid and filtrate through efficient liquid phase chromatographic analysis, the result is: the transformation efficiency of methyl phenyl carbamate is 95.74%, the yield of diphenyl methane diamino acid methyl ester is 80.65%, wherein 4,4 '-diphenyl methane diamino acid methyl ester accounts for 88.93%, 2,4 '-diphenyl methane diamino acid methyl ester productive rate is 7.75%, and all the other are oligomer by products such as three nuclears, four nuclears.
Embodiment 3
Take by weighing the 6.04g methyl phenyl carbamate in thermometer is housed, in the 50ml there-necked flask of condensing reflux pipe and constant pressure funnel, add mass concentration and be 38% hydrochloric acid 10ml (with the mol ratio of MPC be 3: 1) and to be diluted with water to mass concentration be 25% formic acid solution 30ml (be about MPC quality 5 times), stirring is warmed up to 50 ℃, with constant pressure funnel dropwise drip mass concentration be 37% formalin 2ml (with the mol ratio of MPC be 1: 1.5), be warmed up to 90 ℃ after dripping formaldehyde, normal pressure reacted 5 hours down, stop heating, leave standstill cool to room temperature, filter, washing, drying obtains solid product, and gained solid and filtrate are carried out efficient liquid phase chromatographic analysis respectively.The result is: the transformation efficiency of methyl phenyl carbamate is 91.60%, the yield of diphenyl methane diamino formic ether is 78.94%, wherein 4,4 '-diphenyl methane diamino acid methyl ester accounts for 82.17%, 2,4 '-diphenyl methane diamino acid methyl ester productive rate is 6.33%, by product 2, oligomer productive rates such as 2 '-diphenyl methane diamino acid methyl ester, three nuclears, four nuclears are higher, are about 11%.
Embodiment 4
Take by weighing the 7.55g methyl phenyl carbamate in thermometer is housed, in the 100ml there-necked flask of condensing reflux pipe and constant pressure funnel, adding sulfuric acid and phosphoric acid and be in molar ratio the mix acid liquor 5ml (being about 2: 1 with the mol ratio of MPC) for preparing at 1: 1 and being diluted with water to mass concentration is 5% oxalic acid solution 30ml (be about MPC quality 4 times), stirring is warmed up to 50 ℃, with constant pressure funnel dropwise drip mass concentration be 37% formalin 1.3ml (with the mol ratio of MPC be 1: 3), be warmed up to 80 ℃ after dripping formaldehyde, normal pressure reacted 3 hours down, stop heating, leave standstill cool to room temperature, filter, washing, drying obtains solid product, and gained solid and filtrate are carried out efficient liquid phase chromatographic analysis respectively.The result is: the transformation efficiency of methyl phenyl carbamate is 94.67%, the yield of diphenyl methane diamino acid methyl ester is 81.22%, wherein 4,4 '-diphenyl methane diamino acid methyl ester accounts for 91.14%, 2,4 '-diphenyl methane diamino acid methyl ester productive rate is 6.29%, and all the other are by products such as three nuclears and the many phenylcarbamates of multinuclear methylene radical.
Embodiment 5
Take by weighing the 5.29g methyl phenyl carbamate in thermometer is housed, in the 100ml there-necked flask of condensing reflux pipe and constant pressure funnel, add mass concentration and be 85% phosphatase 11 9ml (being about 8: 1) and acetate and oxalic acid mol ratio and be that to be diluted with water to mass concentration at 2: 1 be 10% composite solution 50ml (MPC quality 10 times) with the mol ratio of MPC, stirring is warmed up to 50 ℃, with constant pressure funnel dropwise drip mass concentration be 37% formalin 1.0ml (with the mol ratio of MPC be 1: 2.6), be warmed up to 70 ℃ after dripping formaldehyde, normal pressure reacted 6 hours down, stop heating, leave standstill cool to room temperature, filter, washing, drying obtains solid product, and gained solid and filtrate are carried out efficient liquid phase chromatographic analysis respectively.The result is: the transformation efficiency of methyl phenyl carbamate is 89.52%, the yield of diphenyl methane diamino acid methyl ester is 79.87%, wherein 4,4 '-diphenyl methane diamino acid methyl ester accounts for 87.69%, 2,4 '-diphenyl methane diamino acid methyl ester accounts for by-products contents such as 10.14%, three nuclear, four nuclears and the many phenylcarbamates of multinuclear methylene radical and seldom is about 2.17%.
Embodiment 6
Take by weighing 6.04g methyl phenyl carbamate and 0.6g trioxymethylene (formaldehyde that decomposition obtains and the mol ratio of MPC are 1: 2) in thermometer is housed, in the 100ml there-necked flask of condensing reflux pipe and constant pressure funnel, add mass concentration and be 96% sulfuric acid 11ml (with the mol ratio of MPC be 5: 1) and propionic acid and oxalic acid to be diluted with water to mass concentration in 6: 1 in molar ratio be 28.5% solution 60ml (MPC quality 12 times), stirring is warmed up to 110 ℃, normal pressure reacted 4 hours down, stop heating, leave standstill cool to room temperature, filter, washing, drying obtains solid product, and gained solid and filtrate are carried out efficient liquid phase chromatographic analysis respectively.The result is: the transformation efficiency of methyl phenyl carbamate is 98.32%, the yield of diphenyl methane diamino formic ether is 83.29%, wherein 4,4 '-diphenyl methane diamino acid methyl ester accounts for 90.76%, 2,4 '-diphenyl methane diamino acid methyl ester productive rate is 4.94%, 2, and oligomer by products such as 2 '-diphenyl methane diamino acid methyl ester, three nuclears, four nuclears are about 4.40%.
Claims (8)
1. method for preparing diphenyl methane diamino formic ether in the double solvents system is characterized in that:
Benzene feedstock carbamate, liquid mineral acid catalyzer, plural components solvent are joined in the reactor, stirring is warmed up to 50 ℃, dropwise add methylenation reagent, kept 0～1 hour after being warmed up to 60～150 ℃ of temperature of reaction, add methylenation reagent, reaction system is carried out condensation reaction under normal pressure, after reaction is finished, leave standstill cool to room temperature, filtration, washing, drying obtain the solid product diphenyl methane diamino formic ether;
Described plural components solvent is the plural components solution system that organic solvent-water is formed;
Described organic solvent is one or both the mixture in formic acid, acetate, propionic acid, butyric acid, the oxalic acid.
2. method according to claim 1 is characterized in that: the mol ratio of described reaction system Central Asia methylating reagent and phenyl urethan is 1: 1～4.
3. method according to claim 1 is characterized in that: the consumption of plural components solvent is 3～15 times of quality of phenyl urethan in the described reaction system.
4. method according to claim 3 is characterized in that: the consumption of plural components solvent is 5～10 times of quality of phenyl urethan in the described reaction system.
5. according to claim 1,3 or 4 described methods, it is characterized in that: to account for the massfraction of plural components solvent be 5%～30% to organic solvent in the described plural components solvent.
6. method according to claim 1 is characterized in that: the mol ratio of described liquid mineral acid and phenyl urethan is 1～8: 1.
7. according to claim 1 or 6 described methods, it is characterized in that: described liquid mineral acid is selected from the mixing acid of one or both mineral acids in sulfuric acid, hydrochloric acid, phosphoric acid, the nitric acid.
8. method according to claim 1 and 2 is characterized in that: described methylenation reagent is formaldehyde, trioxymethylene or Paraformaldehyde 96.
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| CN103534231B (en) * | 2011-11-08 | 2016-04-06 | 中国科学院过程工程研究所 | Prepare the method for polymethylene polyphenyl polyamino formate |
| CN106565545A (en) * | 2015-10-12 | 2017-04-19 | 中国石油化工股份有限公司 | Method for continuous catalytic preparation of 4, 4 '-methylene diphenyl dicarbamate |
| CN107434774B (en) * | 2016-05-25 | 2020-06-02 | 中国石油化工股份有限公司 | Method for synthesizing diphenylmethane dicarbamic acid ester from phenyl carbamate |
| CN113926403A (en) * | 2020-06-29 | 2022-01-14 | 中国科学院过程工程研究所 | Preparation device and method of diphenylmethane dicarbamic acid ester |
| CN116617993A (en) * | 2023-07-26 | 2023-08-22 | 中国科学院过程工程研究所 | Device and method for preparing polymethylene polyphenyl polyurethane |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4243815A (en) * | 1979-02-09 | 1981-01-06 | Basf Aktiengesellschaft | Preparation of methylene-bis(4-phenylcarbamic acid esters) |
| CN1775354A (en) * | 2005-12-07 | 2006-05-24 | 中国科学院成都有机化学有限公司 | Catalyst for synthesizing diphenyl methane diamino formic ether |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4243815A (en) * | 1979-02-09 | 1981-01-06 | Basf Aktiengesellschaft | Preparation of methylene-bis(4-phenylcarbamic acid esters) |
| CN1775354A (en) * | 2005-12-07 | 2006-05-24 | 中国科学院成都有机化学有限公司 | Catalyst for synthesizing diphenyl methane diamino formic ether |
Non-Patent Citations (1)
| Title |
|---|
| 裴义霞 等.水溶剂体系液体酸催化合成二苯甲烷二氨基甲酸甲酯.《现代化工》.2007,第27卷第357-360页. * |
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