CN101219972A - Method for synthesizing symmetrical aryl urea compounds - Google Patents

Abstract

The invention relates to a method for synthesizing symmetric aryl urea compounds and the technical scheme adopted by the invention is that with the existence of carbon monoxide, alkali and water, a selenium dioxide is used as a catalyst and nitrobenzene compounds are used as raw materials to carry out carbonylation reaction in an organic solvent under common pressure with a reaction temperature of 50 to 100 DEG C and a reaction time of 5 to 8 hours; a molar ratio of the nitrobenzene compounds to the water materials is 1: 0.5 to 1: 10, and a molar ratio of the selenium dioxide to the nitrobenzene compounds is 1: 25 to 1: 100; a molar amount of alkali accounts for 1 percent to 10 percent of the nitrobenzene compounds; an aromatic ring of the nitrobenzene compounds is not provided with a substituent or is provided with a substituent and a substituent X is the electron-donating groups or the electron-withdrawing groups. The synthesizing method has mild reaction conditions and can be reacted under common pressure with the advantages of simple, convenient and easy operation, easy material acquiring, little pollution, high selectiveness and high production ratio.

Description

A kind of method of synthetic symmetrical aryl urea compounds

Technical field: the present invention relates to a kind of synthetic method of symmetrical aryl urea compounds, relate in particular to a kind of under normal pressure, the method for utilizing tin anhydride catalysis carbon monoxide, water and nitroaromatic reducing carbonyl to be combined to symmetrical carbamide compounds.

Background technology: urea is important medicine of a class and organic synthesis intermediate.Synthetic in the past urea mainly uses the phosgene synthesis method, and phosgene is a poisonous reagent, and produces hydrochloric acid in using to the production unit seriously corroded, thereby people have carried out research widely to the method for non-phosgene synthetic aroma urea now.

Using carbon monoxide to carry out carbonylation in the method for the synthetic urea of non-phosgene now is important method, and because the reaction of carbon monoxide activity is lower, is the key of reaction to the catalysis of carbon monoxide.Use the complex-catalyzed existing report (Ahmcd.M.T. of transition metal (ruthenium, rhodium, palladium); Jens.W.Chem.Rev.1996,94,1047), but catalyzer costs an arm and a leg.Use nonmetal selenium, sulphur to carry out the report (Wang Xiaofang, Lu Shiwei, surplus just female Chinese patent CN1626510A) that the catalysis carbon monoxide carries out carbonylation in addition, but reactive behavior is also not high under condition of normal pressure.

Summary of the invention: the method that the object of the present invention is to provide a kind of synthetic symmetrical aryl urea compounds.This method reaction conditions gentleness, under normal pressure, operate, handy and safe, raw material is easy to get, pollute few, the productive rate height.

For achieving the above object, the technical solution used in the present invention is: a kind of method of synthetic symmetrical aryl urea compounds, with the tin anhydride is catalyzer, in the presence of carbon monoxide, alkali and water, with the nitrobenzene compounds is raw material, carry out carbonylation reaction in organic solvent under normal pressure, temperature of reaction is 50～100 ℃, and the reaction times is 5～20 hours.Be cooled to room temperature, carbon monoxide is switched to oxygen or pneumatic blending, separate out catalyzer, by filtering, underpressure distillation desolventizes, and recrystallization obtains product.

Its reaction is shown below:

The mol ratio of catalyzer tin anhydride and nitrobenzene compounds is 1: 25 to 1: 100;

The mol ratio of nitrobenzene compounds and water is 1: 0.5 to 1: 10;

The mole dosage of alkali is 1% to 10% of a nitrobenzene compounds;

Do not have substituting group on the aromatic ring of nitrobenzene compounds or substituting group is arranged, substituent X is an electron-donating group, and electron-donating group is alkyl or alkoxyl group; Electron-withdrawing group is fluorine, chlorine, bromine, nitro, cyano group or the trifluoromethyl that directly links to each other with aromatic ring.

Described alkali is mineral alkali or organic bases; Described mineral alkali is a sodium hydroxide, potassium hydroxide, salt of wormwood, one or more in yellow soda ash and the sodium acetate; Described organic bases is pyridine, 4-picoline, sodium alkoxide, triethylamine, aniline, triphenylphosphine, 1,5-diaza-bicyclo (5.4.0)-5-undecylene (DBU), 1,5 diaza-bicyclos (5.3.0)-5-nonene (DBN), N-crassitude and 1, one or more of 4-diaza-bicyclo (2.2.2) octane.

Described carbon monoxide is the industrial carbon monoxide tail gas that contains air, hydrogen, nitrogen, carbonic acid gas and/or water vapour, and wherein the content sum of nitrogen, carbonic acid gas and/or water vapour is smaller or equal to 50% of cumulative volume, and air content is less than 30%.

Described organic solvent is one or more polar solvents; Described polar solvent is N, dinethylformamide (DMF), dimethyl sulfoxide (DMSO) (DMSO) and formyl piperidine (FP).

The present invention has following advantage:

1. the present invention is a synthesis under normal pressure.Facility investment is few, and is easy to operate and safe.

2. cost is low, and the catalyzer tin anhydride is cheap, and the reactant nitrobenzene compounds need not be reduced to amino can change into urea by direct carbonyl.

3. environmentally friendly.The present invention reacts the three wastes and handles obviously minimizing of burden, has reached the requirement of cleaner production, helps large-scale industrial production.

4. reaction process is easy.

5. good economy performance.Speed of response of the present invention is fast, the productive rate height.

Embodiment:

Below by embodiment in detail the present invention is described in detail, but the invention is not restricted to following embodiment.

Embodiment 1

Have at 100ml and to add tin anhydride 0.044g (0.4mmol) in the there-necked flask of prolong and stirring, oil of mirbane 1.41g (10mmol), water 2ml (0.01mol), sodium acetate 0.041g (0.5mmol) and solvent DMF 40ml, continue to feed carbon monoxide, and be heated to 90 ℃ of reactions 5 hours, and be cooled to room temperature, carbon monoxide is switched to oxygen or pneumatic blending after half an hour, suction filtration, the filtrate decompression distillation removes desolvates, and gets product sym-diphenylurea 0.96g, yield 91% with ethyl alcohol recrystallization again.

Embodiment 2

Method is with embodiment 1, and is as follows for the yield of different nitrobenzene compounds:

Raw material (substrate)	Product	Yield %
			4-methyl-oil of mirbane	4,4 '-dimethyl sym-diphenylurea	88％
4-chloro-oil of mirbane	4,4 '-dichloro sym-diphenylurea	90％
			4-cyano group-oil of mirbane	4,4 '-dicyano sym-diphenylurea	89％
2-chloro-oil of mirbane	2,2 '-dichloro sym-diphenylurea	78％
			4-nitro-oil of mirbane	4,4 '-dinitrobenzene sym-diphenylurea	90％
4-alkoxyl group-oil of mirbane	4,4 '-dialkoxy sym-diphenylurea	88％
			4-trifluoromethyl-oil of mirbane	4,4 '-two trifluoromethyl sym-diphenylurea	82％

Embodiment 3

Method only changes the consumption of water with embodiment 1, and yield is as follows:

The water yield (ml)	Oil of mirbane and water mol ratio	Time (hr)	Yield (%)
				1	1∶0.5	5	89
2	1∶1	5	91
				4	1∶2	8	90
10	1∶5	10	84
				20	1∶10	20	56

Embodiment 4

Method only changes catalyst consumption with embodiment 1, and yield is as follows:

Tin anhydride (g)	The mol ratio of tin anhydride and oil of mirbane	Yield
			0.011	1∶100	34％
0.022	1∶50	53％
			0.033	1∶33	75％
0.044	1∶25	91％

Embodiment 5

Method only changes the consumption of sodium acetate with embodiment 1, and yield is as follows:

Sodium acetate (g)	The sodium acetate amount is the per-cent of oil of mirbane molar weight	Yield
			0.008	1％	43％
0.016	2％	65％
			0.041	5％	91％
0.082	10％	91％

Embodiment 6

Method is with embodiment 1, and is as follows for the yield of Different Alkali:

Alkali	NaOH	Pyridine	Yellow soda ash	DBU	The 4-picoline	Salt of wormwood
							Amount (mmol)	0.5	0.5	0.5	0.5	0.5	0.5
Yield (%)	34	45	76	34	23	87

Embodiment 7

Method is with embodiment 1, and is as follows for the yield of different solvents:

Solvent	DMF	DMSO	FP
				Amount (ml)	40	40	40
Yield	91％	45％	75％

Embodiment 8

Method is with embodiment 1, and is as follows for the yield in differing temps and reaction times:

Temperature of reaction (℃)	50	60	80	90	95	100
							Reaction times (hr)	11	9	7	5	5	5
Yield	45％	75％	87％	91％	91％	60％

Claims (6)

1. the method for a synthetic symmetrical aryl urea compounds, it is characterized in that with the tin anhydride being catalyzer, in the presence of carbon monoxide, alkali and water, with the nitrobenzene compounds is raw material, in organic solvent, under normal pressure, carry out carbonylation reaction, temperature of reaction is 50～100 ℃, and the reaction times is 5～20 hours; Be cooled to room temperature, carbon monoxide is switched to oxygen or pneumatic blending, separate out catalyzer, filter, the filtrate decompression distillation desolventizes, and recrystallization obtains product;

Its reaction is shown below:

The mol ratio of catalyzer tin anhydride and nitrobenzene compounds is 1: 25 to 1: 100;

The mol ratio of nitrobenzene compounds and water is 1: 0.5 to 1: 10;

The mole dosage of alkali is 1% to 10% of a nitrobenzene compounds;

Do not have substituting group on the aromatic ring of nitrobenzene compounds or substituting group is arranged, substituent X is electron-donating group or electron-withdrawing group, and electron-donating group is alkyl or alkoxyl group; Electron-withdrawing group is fluorine, chlorine, bromine, nitro, cyano group or the trifluoromethyl that directly links to each other with aromatic ring.

2. according to the method for the described a kind of synthetic carbanilide compounds of claim 1, it is characterized in that described alkali is mineral alkali or organic bases.

3. according to the method for the described a kind of synthetic carbanilide compounds of claim 2, it is characterized in that described mineral alkali is a sodium hydroxide, potassium hydroxide, salt of wormwood, one or more in yellow soda ash and the sodium acetate; Described organic bases is pyridine, 4-picoline, sodium alkoxide, triethylamine, aniline, triphenylphosphine, 1,5-diaza-bicyclo (5.4.0)-5-undecylene, 1,5 diaza-bicyclos (5.3.0)-5-nonene, N-crassitude and 1, one or more of 4-diaza-bicyclo (2.2.2) octane.

4. according to the method for the described a kind of synthetic carbanilide compounds of claim 1, it is characterized in that described carbon monoxide is the industrial carbon monoxide tail gas that contains air, hydrogen, nitrogen, carbonic acid gas and/or water vapour, wherein the content sum of nitrogen, carbonic acid gas and/or water vapour is smaller or equal to 50% of cumulative volume, and air content is less than 30%.

5. according to the method for the described a kind of synthetic carbanilide compounds of claim 1, it is characterized in that described organic solvent is a kind of polar solvent.

6. according to the method for the described a kind of synthetic carbanilide compounds of claim 5, it is characterized in that described polar solvent is N, dinethylformamide, dimethyl sulfoxide (DMSO) and N-formyl piperidine.