DE1952991A1 - Process for the preparation of imidazoles - Google Patents

Description

DR.-ING. WALTER ABITZ DR. DIETER F. MORF DR. HANS-A. BROWN

Patent attorneys

Munich,

Postal address 8 München 86, Postfach 860109

Pienzenauerstraße 28 Telephone 483225 and 486415 Telegrams: Chemindus Munich

October 21, 1969 832

MERCK * CO., INC. 126 East Lincoln Avenue, Rahway, N.J. 07065, V.St.A.

Process for the preparation of imidazoles Mixtures of alkylene! Amines of the general formula

NH ₂ MHR ₂

in which R and R _{2 are} hydrogen, lower alkyl, aryl or aralkyl, and from carbonyl compounds of the general formula

in which R _{1 is} hydrogen, alkyl, cycloalkyl, aryl or aralkyl

and R ~ hydrogen, -OH, -O = R or P

^p -0-CR ₁

009819/1869

-a-

mean are based in the presence of a catalyst of copper and / or chroa with the formation of imidasols of the general formula

I- H

-U-

R ₂

in which R, R ₁ and R _{2 have} the meanings given above, evaporates. The imidazoles are produced by forming a mixture of the diamine and the carbon oil compound in the liquid phase, evaporating the liquid hybrid and the evaporated mixture at a temperature between 320 and 650 ° C through a bed of catalyst based on solid copper and / or chrome is piped. The vapors leaving the reactor are condensed and purified to obtain the desired iaidaz oil compound. Imidazolines are also converted into imidazoles using the same process.

The present invention relates to the preparation of imidazoles and in particular a vapor phase synthesis of imidazoles in the presence of a catalyst based on Copper and / or chromium.

Imidazoles are well-known compounds that are used as textile treatment « Auxiliaries, epoxy hardeners, catalysts for polyurethane foam, surfactants, antistatic agents, fungicides, bacterialides, therapeutic agents and intermediates' are useful in the manufacture of pharmaceuticals. Tnsbeson ^ other kitroimldazoles are useful as therapeutic agents.

-2 009819/1869

Imidazole compounds were made from alkylenediamines and carbonyl compounds or from imidazolines by vapor phase reaction produced in the presence of noble metal catalysts.

Precious metal catalysts are expensive and usually are deposited on an inert carrier, which requires care that uniform distribution is obtained. In addition, precious metal catalysts are through certain Substances such as sulfur, heavy metals or the like, easily poisoned and cause undesirable lifting reactions, if they are contaminated with halide. Noble metal catalysts require careful purification of the reactants and the Catalyst production before implementation.

The general purpose of the present invention is to provide a process used by catalysts based on copper and / or chromium for the conversion of mixtures from alkylenediamines and carboxyl compounds in the vapor phase makes use of imidazoles.

Similarly, imidazolines are converted into the corresponding Imidazole converted.

The catalysts used are based on copper and / or chromium are cheap, and they represent commercially available substances that do not require any transformations before use. These catalysts are not easily poisoned and do not cause any undesirable tremor reactions. I am a catalyst in which both copper and chromium are combined are like copper chromite (the like, is because of the good yields of the desired imidase oil compound be » especially preferred.

009819/1869

BATH ORIGINAL

It is an object of the present invention to provide an improved seed phase synthesis of imidae oil compounds.

Another goal is to provide a method »that of a cheaper and more readily commercially available catalyst material than has been used hitherto power.

Another object of the invention is to provide a vapor phase process that uses catalysts on the ground. layer of copper and / or chrome (the brau oh makes that not easy are poisoned and have no undesirable side reactions cause.

Another goal is a good yield obtained through the use of copper chroaite catalysts.

According to the present invention, imidazoles are produced by reacting an alkylenediamine with a carbonyl compound such as a monoarboxylic acid or its anhydride, ester or aldehyde, in the vapor phase over a heated, solid catalyst made on the basis of copper and / or chromium. The reactants are mixed, if desired, preheated and introduced into a reaction vessel which has an inert preheating section, a section with a fixed catalyst bed based on copper and / or chromium and an inert carrier having gerabgchnitt.

The preheating catalyst and support section of the reactor are heated by external heating or by passing preheated through Hydrogen through the bed to the desired react

BATH ORIGINAL

tion temperatures brewed. The mixture of alkylenediamine and a carboxy compound is added at a controlled rate along with a controlled amount of hydrogen, which, if desired, can be preheated to maintain the reactor temperature, introduced into the reactor. The preheating section of the reactor causes that the liquid loading material evaporates practically completely, before it comes into contact with the copper catalyst, the vaporized reactants and hydrogen gas then flow through the catalyst bed in which the conversion to the desired imidaz oil compound occurs. The reactants and Imidazole in vapor form is released from the catalyst bed section through the support section into a cooled condenser, in which the imidazole compound condenses, is. Hydrogen gas and other vapors are released from the condenser for cleaning in a suitable sprinkler tower directed. (If desired, the hydrogen can be recycled). The condensate becomes Obtaining the imidazole product is distilled, preferably under reduced pressure to prevent polymerization and thermal degradation of the product. the Imidazoles can also be obtained by precipitation from a suitable solvent, such as dilute acid, benzene, methylene chloride, Chloroform or the like.

Suitable alkylenediamine reactants are those that stickst off atoms on adjacent carbon atoms of the alkylenediamine exhibit. These reactances are given by the general

formula

HIGH

R. R. » 0 C - C - t > HH ₂ CLOCK"

009819/1869

_ßAD

described in which R and R _{2 are} hydrogen; Lower alkyl such as methyl, ethyl, propyl, butyl, or the like; Aryl with 6 to 10 carbon atoms, such as phenyl, tolyl, XyIyI or the like} or aralkyl with 6 to 10 carbon atoms, such as 2-phenylethyl, benzyl or the like, mean · The primary alkylenediamines (R ₂ represents hydrogen) are particularly preferred where R is hydrogen, alkyl having 1 to 4 carbon atoms or phenyl. Representative of the alkylenediamine reactants are ethylenediamine, propylenediamine-1,2, S-methylethylenediamine, butylenediamine-2,5, 1-phenylpentylenediamine-3 »4, 1-phenylpropylenediamine-2,3, H ~ phenylethylenediamine, 1-phenylnonylenediamine-3, 4, diphenylethylenediamine, i-xylylpropylenediamine-1,2 or the like.

Suitable carbonyl compounds are those of the general formula

in which R _{1 is} hydrogen; Alkyl having 1 to 1 carbon atoms such as methyl, ethyl, propyl, hexyl, nonyl, dodecyl or the like; Cycloalkyl with 5 to θ carbon atoms, such as cyclohexyl, Cyc1openty1, cycloheptyl or the like; Aryl having 6 to 10 carbon atoms such as phenyl, tolyl, xylyl, or the like; or aralkyl with 6 to 10 carbon atoms, such as 2-phenylethy1, benzyl or the like, and R- hydrogen,

-OH, -0-R or?

-0-CR ₁

mean, where R and R _{1 have} the same meanings as above. Particularly preferred are carbonyl compounds ι gen that have no more than 7 carbon atoms, par-

- 6 009819/1863

BATH ORIGINAL

der · the Bledrlgalkansäuren and Benzoic acid. Eepreentative for dl carboxyl compounds are formaldehyde, acetaldehyde, Proplonaldehyd, Bensaldefayd «Eaenylaoetaldehyd, n-Hexanol, Formic acid, laelgetture, propionic acid, decanoic acid, dodecanoic acid, Octadeoanoic acid, oyolohexanoarboxylic acid, benzoic acid, Tolu oleic acid, phenylacetic acid, methyl formate, ethyl formate, Methyl acetate, ethyl propionate, phthalene acetate, aayl propionate, Methyloyolohexan-Carboxylat, NethyXbeniOftt, Methylphenaoetat, BeeigeKureanhydrid »ProploneKureanbydrid, BenBoeedureanhydrld and the same.

The Alkylen and Carbonylreaktatiten are known or are produced according to known working methods. It should be noted that the symbol R in the general alkylenediamine is five ormel mean the same or different substituents can and that Rg substituents have the same meaning as the R have or can be different from substituents.

The IaI-dasols produced by the process according to the invention can through the general formula

- ■ "2

are shown in which the symbols R, R ₁ and R _{2 have} the meanings defined above. Representative of the imide oils produced according to the invention eJnäj imidasol, 4 (5) -Nethylimidaiol, 4 (5) -A * thyllmidazole, ((5) -phenylimidacol _t 4 (5) -BenBylimida «ol, 4 (5) -Iolyllmidaeol, 4- Fropyl-5-phenyllml

009819 / 18S9

daro oil, 1,4-dimethylimidazole, i-benzyl-5-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-undeoylimidazole, 2-ethyl-4-methylimidazole, 2,4 (5) -rinethylinsidazole, 2 -Heptadeoylimidaeol ,, 2-Fhenylimldazol, 2-Ethyl-4 (5) -phenylimidazol, 2-Ethyl-4 (5) -beneyllaida8Ol, 2-Methy1-4 (5) -tolyllmidazol, 1-XthyliBidftBOl, i-Tolyl ^. S-diaethyliMidaeol, 2-phenyl-4 (5) -methylimidaiol, 2,4 (5) -liphenyli-idaeol, 2-phenyl-4 ( 5 ) -beneyl aldacol, 2-phenyl-4- methyl-5-xylylitnidaiol, 1 -FhenyllmidaEol, 2-BenBylimidazol, 2-Phenylttthy1-4 (5) -aethyllaidaeol, 2-Tolyl-4 (5) -phenylimidatol, 2-Xylyl-4-phenyl-5-ttthyliiDidaEol, 2-0yclopentyl-4 (5) - methylimidaBol and 2-0yolohexylinidaeol.

The alkylenediamine and carbonyl reactants come in handy same molecular ratios combined, although MoI- ▼ ratios from 1.0 to 1.3 moles of the carbonyl compound any mole of diamine can be used.

The reactants are combined and used to make a Fill it up, preferably heated. Not mixable Reactants are agitated to prevent settling.

The mixture of reactants flowing into the reactor is carried along with it an hourly TlUsslgkelts space velocity (volume the liquid / volume of the catalyst / hour) of at least 0.01 and preferably with a space velocity between 0.1 and 4 initiated.

The catalytic reaction is preferably in the presence of carried out added hydrogen gas. The added water st off amount is generally 0.1 to 15 mol of hydrogen

- 8 009819/1869

BATH ORIGINAL

-1"

gas per mole of alkylenediamine reactant fed to the reactor. Preferably 2 to θ moles of hydrogen gas per mole Diamine used. The hydrogen gas improves the yields » by keeping the catalyst free of unwanted deposits and extending the life of the catalyst.

The liquid reactants and hydrogen gas are released from the Inlet opening of the reactor into a preheating section which is composed of a bed of light, inert particles is ι which evaporate the liquid reactants and the vermisohen of the reactant vapor with hydrogen gas support. The preheating unit and the catalyst bed are held at 320 to 650 ° 0 to ensure complete evaporation and conversion. The Particles of Before ", any suitable inert material, such as alundum, quartz, porcelain, stainless steel or the like.

The mixture of vaporized reactants and hydrogen passes from the preheating section into the catalyst section, which is kept at a temperature of 320 to 650 ° C, and in which the conversion into the desired imidaz oil compound takes place

The catalyst can be any mild hydrogenation or dehydrogenation catalyst be based on copper and / or chromium, such as copper oxide, which is used to hydrogenate aldehydes used to make alcohols, chromium-alumina »which is used for dehydration is used, or Hopper, which is used for selective Hydrogenation or dehydrogenation of fractional groups in organic compounds or changes in saturation

- 9 00S819 / 1869 BATH

or unsaturation in aromatic rings or alkyl chains or which is used. The copper chromite catalysts, such as copper chromite, a barium promoter, are particularly preferred containing eupferohromite, cadmium copper chromite and the same. Most preferred because of the good looks the prey is cadmium copper chromite.

Many of the catalysts are called hydrogenation catalysts Delivered in a higher value condition. For use in the method according to the invention, these Catalysts reduced in situ by conventional methods before the reaction.

The following table lists some of the commercially available catalysts used in the process of the invention.

Commercial catalysts based on copper and / or chromium.

catalyst

description

Harehaw Cu-1700 T 3 »175 mm black, containing 79 # CuO

(1/8 ») tablets

"Cu-0307 T 3.175mm black containing 99 # CuO

Tablets

It It

Cu-0803 T 3.175 mm

i> CuO on highly active alumina

Cu-0203 T 3.175 mm 80 # CuO and 17 ^ Cr ₂ O- contained =

terde tablets ^p

Cu-0402 T 3t175 mm eiten containing barium ^ promoter

Tablets containing 3596 CuO, 38 # Cr ₂ O ₃ and 10 $> BaQ

Cu-1407 T 3.175 mm 37 $ CuO and 52 i » Cr ₂ O, containing tablets °

- 10

009819/1869

BATH ORIGINAL

catalyst

airdler 0-13 ^N 0-22

"T-988

■ T-317

• β-41 Harshaw Cr-O104 T 3.175

"Or-Oi03 T 3f175

description Copper Chrome In Tablet Phone

Containing a Bariua Proaotor Copper chrome

Cadalua copper chroaite, which contains 27 1 » Cd, 18 % Cu, 27 * Cr and the remainder O ₂

Copper oxide, which is 10-12 ft of copper contains activated clay

Ohroaoxld clay tablets

Ohrob alumina containing 5 Jl Cr ₉ O. on activated alumina ⁹ ChroB ion earth containing 12 l Cr ₂ O on activated alumina ⁷

The most common substances leave the catalytic converter, stream through the porter unit and are chilled into a Condensation apparatus emptied, in which the Ialdasol connection is won.

Another embodiment of this invention is a method sua Uawwandeln von Ialdaeolinen in their corresponding Iaidasole by Daapfphasen Defcydrlerung in the presence of a Catalyst based on copper and / or chromium. Imidazolines are well-known intermediates that la general by heating an alkyl amine and a monocarbon acid, preferably with the removal of formed water.

It was found that Ialdascline, which is of the general formula

- 11 009819/1869

bath

correspond, in which the symbols R, R ₁ and R _{2 have} the meanings given above, au cem corresponding imidazole (formula I) are dehydrogenated when they are in the presence of a catalyst based on copper and / or chromium, such as copper oxide, chromium Alumina, copper chromite and the like, are vaporized at a temperature of 320 to 630 ° 0 «Imidazolines in which R _{2 is} hydrogen, R _{1 is} hydrogen, Nledrigalkyl or phenyl and R is hydrogen, alkyl with 1 to 4 carbon atoms or phenyl are special preferred. Preferred catalysts are copper chromite, copper chzomite containing a barium promoter, cadmium copper chromite and the like, in particular cadmium copper chromite.

Imidazolines are made under the same process conditions as they in the reaction of an allylenediamine with a carbonyl compound are applied to form icidazole, converted into imidazole. The Imide.zolin is used as a liquid in A heated reactor was introduced, in which the heating was started evaporated, dehydrated in the catalyst section and emptied into a cooled Kondense.tionaapparat. That condensed Imidazole product is further purified by distillation or crystallization.

The invention is illustrated by the following specific examples for the preparation of imidazel compounds, however not limited.

example 1

116t5 g (1.9 mol) of ethylenediamite and 99.5 g (1.9 mol) of formic acid are placed on a steam bath to form a homogeneous, clear solution mixed. The solution is in a with

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009819/1869

BATH ORIGINAL

a graduated feed funnel provided with a steam jacket filled.

Sin quartz reactor with a diameter of 2.9 cm is with 100 ml Alundum Fellets loaded to an inert carrier removal form fsu. Han gives 50 ml of the qadmium raw copper catalyst (Girdler T 988 pellets) and then 125 ml Alundum pellets to which are to serve as prepayment section " The quartz reactor is installed in an electric drilling furnace. 572 ml of hydrogen gas are fed into the reactor per minute initiated, which is heated to 480 ° C by means of the electric tube furnace · You formic acid-ethylenediamine solution is fed into the reactor at a rate of 0.7 ml / hour measure what is an hourly liquid space velocity (hereinafter referred to as LHSY) of 0.84. The molar ratio of ethylenediamine to formic acid is 1.0 and the molar ratio of hydrogen gas to ethylene diamine 3.78.

The material flowing out of the reactor is led into a cooled collecting vessel, where a dark liquid is located condensed. Hydrogen gas and other vapors are in a Gas washing bottle drained with 6N sulfuric acid »The condensed Product is obtained by vacuum distillation and recrystallized from benzene · Xmidasol is obtained (melting point 89-91 ° 0) in a yield of 53.4 ^.

Following the procedure of Example 1, imidazole is also obtained if you have 5t g (1.9 mol) of formaldehyde or 114 g 0.9 mol) Methyl form! At instead of the formic acid used in Example 1 used·

- 13 *

As in the example given above, a thaw-solar pleasure becomes ie ch made from propylenediamine-1,2 and formaldehyde and filled into a heated feed funnel. Base aldehyde-propylenediamine mixture becomes old constant speed of

1.4 ml per minute (LHSV is 1.68) of the Quarsreaktor sugemessen, the 50 al 3 »175 aa-Chroa-Clay Iatalyeator {Barshaw Or-0104 T) and kept at a temperature of 460 ° C will. At the same time, enough water off gas is supplied, around a hydrogen to propylene dial ratio of

4.5. Bee escaping from the reactor Material is collected in an elnea cooled Xondensatlonsapparat and distilled. 4 (5) -Methyliaidasol (melting point) is obtained. 136-140 ° 0).

1.9 moles of 1-phenylethylenediaaine and 1.9 moles of methyl formate are mixed with one another and placed in a graduated feed funnel which has been previously provided with a steam jacket. The reactants are added to the reactor used in Example 1, which contains 50 μl of copper oxide catalyst. The reactor is kept at 380.degree. The reactants are given a constant wind speed of 1.1 times per minute, which is equivalent to an IBSV of 1.32. The eol & re ratio of Diaain eu formate is 1 »0 _v and the molar ratio of hydrogen to 1-phenylethylendlaaln is kept at 4s 1. The material flowing out of the reactor is saaaelt in a cooled condenser and distilled to obtain 4 (5) ~ PhenyliMidaeol.

In a similar catfish, if one uses the formic acid and Xthylendiaain reactant of Example 1 by a reaction mixture of itaylendlaain and Äthylfonalat; Butylenediamine-2,3 and alleic acid; i-phenylpropylenediaein-2,3 and 7formaldehyde;

BAD ORfQiNAk

I-methylethylenedianine and acidic acid; and 1-tolylethylenedianine and formic acid replaced, isidasol, 4,5-Diaethylisidaeol, 4 (5) -Bensyli * idasol, 1-Methylieidasol and 4 (5) -Tolylisidasol.

Example 2

15.10 g (0.124 mol) benzoic acid and 8.80 g (0.U7 mol) ethylene * diasin are smoked in a steam bath and in one «Filled with a feed funnel provided with a Waeserdaspftoantel.

Am Quarsrohr «it is a Burohseeser of 2.54 es (1 inch) sit Alundua-Pellet «, which are supposed to serve as a carrier. 15 al Oadsius copper chrosite catalyst (Oirdler T-988) and then enough Alundua pellets EugefUhrt, us to issue a 17.8 cs approval resignation. The reactor is heated to 372 ° C, and 217 si Wasseratoffgae are ever Minute introduced into the reactor.

The BenBoesaurs-IthylendiaBin-Oesisoh becomes the most popular reactor sit at a speed of 11.3 ss / hour, the corresponds to an LBSV of 0.76, sugeseesen. The solar ratio from itfaylendlasin eu Bonsoee & ure is 1.185 and the solar ratio of Waeenretoff to Ethylendiasin 7.0. The material flowing out of the reactor is placed in a cooled Collecting vessels gesaasel-c, and the vapors are in a wash bottle is drained from 0.1N HCl.

The material emitted from the reactor condenses in Fors a β yellow solid. The solid is in 104 si 1, On hydrochloric acid and 25 si distilled water under easy swarming solved. ! This material is surely

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009819/1869

- st filtered through Supereel, crystallized and with 25 ml washed with distilled water »The one with the washing solutions The purified piltrate is treated with 50% sodium hydroxide (2.2 ml to pH β). The precipitate formed will filtered off, and the mother liquors with 50 tigern sodium hydroxide »Treated to pH 11. Ee a swelter forms Precipitate, which is also filtered off. The precipitated solids are combined; the yield is 32.4% 2-Fhenylmldazole, which has an isolated purity of 98 + 1 * the UV analysis.

2-Phenylimidazole can also be prepared as in Example 2, by the cadmium copper chroaite catalyst through a Ghrome-alumina catalyst (Harehaw Cr 0104 T) replaced and under Use the same reactants and process conditions except that the reaction temperature is 450 ° C is held, is being worked.

2-Phenylmidazole is also produced by replacing the benzoic acid used in Example 2 with equimolar proportions of benzoic anhydride _9, methyl benzoate or benzaldehyde. For example, 16.9 g (0.124 mol) of methyl likewiseate and 8.80 g (0.147 mol) of ethylenediamine are mixed on a steam bath to form a solution which is placed in a feed funnel covered with a water hood.

A quartz tube with an office knife of 2.54 cm is used with Alundum pellets loaded to serve as a carrier. Man add 15 ml of catalyst and then 35 ml of alundum pellets to to form a Torerhitzungsabohnitt. About the reactor is on 399 ° C heated, and 217 ml of hydrogen gas are per minute introduced into the reactor.

- 16 -

009819/1869

BATH ORIGINAL

The methyl benzoate and ethylenediamine solution is metered into the gel reactor at a flow rate of 10.3 ml per hour (IH8V * 0.69). The molar ratio of hydrogen to ^ ethylenediamine is 5.8 · The material flowing out of the reactor is collected in a cooled collecting vessel. This gives 2-Phenyliaidaeol (Ip. · 147-148 ⁰ C).

If a mixture of benzaldehyde and ethylenediamine in the molar Ratio of 1.18 (benzaldehyde to ethylenediamine) at 370 ° C when using an LHSV of 1.07 and 3.7 mol of hydrogen per mol of ethylenediamine, 2-phenylimldazole is obtained.

When benzoic acid or its ester, anhydride or aldehyde with propylenediamine-1,2, H-phenylethylenediamine, pantylenediamine-2,3, i-phenylpropylenediamine, 1-phenylethylenediamine _t butylenediamine-1,2, 1-xylylethylenediamine and butylenediaaine 2, 3 are reacted, one obtains 2-phenyl ~ 4 (5) ~ methylimidazole, 1,2-diphonylimidazole, 2-phenyl ~ 4 ( 5 ) -oethyl-5 (4) ~ ethylimidazole, 2-pheny1-4 (5) -benzyliaidazole, 2-phenyl-4 (5) -phenylimidazole, 2-phenyl- $ (4) -äthyllmldasol, 2-phenyl4 (5) -xylylimidazole and 2-phenyl-4,5-dimethylimidaaol.

! If a cycloalkyl aralkyl or alkaryl Csrbonylverbindung as hexahydrobenzoic, hydrocinnamic, Phenylesaigsäure, Holuolsäure and Isoxy oleic acid, is reacted with Ithylendiamin, gives 2-cyclohexyl, 2- (2 ^t -Phenylätbyl) -, 2-benzyl , 2- (Hethylphenyl) - and 2- (2 ·, 5 ^f -dimethylphenyl) -imidazole.

- 17 -

009819/1869

example

116, § g (1 * 9 mol) ethylenediaain and 114 g (?, 9 mol) acetic acid are smelt in a steam bath and in a graduated Sulauftrlohter with a water jacket filled. The response level becomes continuous dea reactor used in Example 1, the 50 al Cadaiuakupferchroalt catalyst contains, in the event of a fluid flow measured from 0.7 al per minute. Simultaneously Hydrogen gas is added old at a rate of 572 al per minute. The reactor is operated during the setting an electric bobrofene heated to 480 ° C. the hourly Plüsslgkelts-Rauageichwlndigkelt is 0.84, the The molar ratio of ethylene diaal to acetic acid is 1 and the molar ratio of hydrogen au ethylenediaaln 3 t78. Bas off The effluent material from the reactor is collected in a refrigerated condenser and the vapors are discharged into a Qaswaschflasehe old sulfuric acid drained. Bas condensed Product is obtained by vacuum distillation. 2-Methyllaldazole (Pp * * 136-140 ° C.) is obtained.

If the acetic acid of Example 3 is replaced by propionic acid, fropionaldehyde, methyl propionate or propionic anhydride, obtained on 2-Xthylialdaaol (mp.> 61-64 ° C).

If acetic acid is used under the conditions of Example 3 old propylenediamine-1,2, butylenedialn-2,3 ₉ 1-phenylethylenedial and 1-xolylethylenedial, 2-methyl-4 (5) -aethyllaldasol, 2,4,5- is obtained Triaethyliaidassol * 2-methyl-4 (5) -phenylialdaaol and 2-methyl-4 (5) -tolyliaidazole.

- 18 -

009819/1868 bad original

If a an alkyl alkyl compound. such as pentanoic acid, dodeoanic acid or Ootadecans & ure, «it converts ethylenedlamine, receives aan 2-Butyl-, 2-Undeeyl- and 2-HeptadecylimidaEol

Example 4

A Quars reactor with a diameter of 2.9 cm is charged as in Example 1 with 100 al Alundua, 50 al Gadaiua copper chrome catalyst and 125 al Alundua. The reactor is trhitst to 480 ° 0, and IaIdasolin is the reactor at a rate of 0.7 al / minute (IBSY m 0.84) sugeaessen 572 al hydrogen gas are discharged from the reactor at the same time per minute, including a molar ratio of What β only off su Iaidasolln from 3t78 su maintained. The material flowing out of the reactor is condensed in an outer collecting vessel and gives Iaidasol, which is distilled at the bottom and purified by crystallization from bees oil.

If 2-Methyllaldasolln · 2-Xthyliaidasolin, 2-Heptadecyllaidasolin, 2-Ihenylialdasolin _v 2-Tolylieidaeolin, 2,4 (5) -Diaethyllaldaeolln, 2-ethyl-4 (5) -aetnyllaldaEolin, 2-Phenyl-4 (5) - aethyliaidaBOlin, 2-Cyclohexyliaidaeolin, 2-Bensyliaidasoln or 1-Nethylialdasoline are evaporated and kept in the presence of a catalyst based on copper to form 2-Methylialdasol · 2-lthyliaidasol, 2-Beptadeoylaldasol, 2-fhenylaldasolid, 2-Tolylaldasol, 2-Tolylaldasol , 4 (5) -Diaethyliaidasol, 2-ethyl-4 (5) -aethyllaldasol, 2-Fhenyl-4 (5) -aethyllaldasol, 2-Cyclohezyliaidasol, 2-Bensylialdasol and 1-MethyliBidasol.

- 19 -

009819/1869

ar-

Example 5

15.10 g (0.124 mol) benzoic acid and 8.80 g (0.147 hol) ethylenediamine are savored on a steam bath until a homogeneous, clear, yellow solution has been obtained. This solution (23.9 g * 20.2 nl) is in a with a water vapor jacketed feed funnel filled

A quartz reactor with a diameter of 2.9 cm is filled with 100 ml of alundum pellets and then with 50 ml of chromium-alumina catalyst (Harshaw Cr-O104) and then loaded with 125 nl Alundun to serve as a gate heater. The reactor will be 730 ml / minute (SIF) hydrogen gas supplied. The reactor is heated to 450 ° C by means of an electric tube furnace. The benzoic acid-ethylenediamine solution is flowing at a constant rate of 0.58 ml / minute (LHST * 0.7) the bed 35 Measured for minutes.

The material flowing out of the reactor is placed in a collecting vessel drained, in which a yellow solid recovered will. The solid is purified as in Example 2 to give 2-phenylinidazole.

2-Phenylimldazole is also obtained when Example 5 is repeated replacing the chromium-alumina catalyst with 50 ml of copper oxide catalyst (Girdler T-317).

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BATH ORIGINAL

Claims (20)

852 October 21, 1969 P a t e η t a η s ρ r ü c h e 1. Method for Herateeile of Imidaβol Yerbindungen formula in which R and R _{2 are} hydrogen, lower alkyl, aryl ait up to 10 carbon atoms or aralkyl with 6 to 10 carbon atoms »where each of the R and the R ₂ substituents can differ from the other, and R ₁ hydrogen 1 alkyl, cycloalkyl with 5 to 8 carbon atoms, aryl with 6 ^X to 10 carbon atoms or aralkyl with 6 to 10 carbon atoms, characterized in that (a) an alkylenediamine of the formula RR I 't H-C-C-H »I. MH ₂ NHR ₂ with a carbonyl compound of the formula mixed, where R, hydrogen, OH, QR or 0-CR ₁ and the symbols R, R ₁ and R2 have the same meaning as above, - 21 - 009819/1869 -η- (b) the mixture evaporates and (c) the vapors obtained with a solid catalyst, containing a metal selected from the group consisting of copper, chromium and combinations thereof, at a temperature in the range from 320 to 650 ° C. 2. The method according to claim 1, characterized in that the catalyst is a copper chromite catalyst, 3. The method according to claim 1, characterized in that the bringing into contact of the vapors of the mixture in ) Presence of added hydrogen gas makes. 4. The method according to claim 3, characterized in that the carbony! compound has no more than 7 carbon atoms Has. 5. The method according to claim 4, characterized in that the catalyst is a copper chromite catalyst. 6. The method according to claim 5, characterized in that the carbony compound is a honocarboxylic acid from the group Is lower alkanoic acids and benzoic acid. 7. The method according to claim 6, characterized in that R _{2 is} hydrogen and the hydrogen, alkyl having 1 to 4 carbon atoms or phenyl. 8. The method according to claim 7, characterized in that the catalyst is a cadmlum copper chromite catalyst. 9 * The method according to claim 8, characterized in that the primary alkylenediamine is ethylenediamine. - 22 - 009819/1869 '' BAD ORIGINAL 10. The method according to claim 9 »characterized in that the monocarboxylic acid is benzoic acid. 11. The method according to claim 9t, characterized in that the honocarboxylic acid is formic acid " 12. Process for the preparation of imidazole compounds of Formula. in which R and R _{2 are} hydrogen, lower alkyl, aryl having 6 to 10 carbon atoms or aralkyl having 6 to 10 carbon atoms, wherein each of the R and R ₂ substituents can be different from the other, and R _{1 is} hydrogen, alkyl, cycloalkyl with 5 to 8 carbon atoms, aryl with 6 to 10 carbon atoms or aralkyl with 6 to 10 carbon atoms, characterized in that (a) an imidazoline of the formula in which the symbols R _1, R ₁ and R _{2 have the} same meaning as above, evaporated and (b) the vapors obtained with a solid catalyst which is a metal selected from the group consisting of copper, chromium and combinations it contains, at a temperature in the range of 320-650 ° C. - 23 - 009819/1869 -av- 13. The method according to claim 12, characterized in that the catalyst is a copper chromite catalyst. 14. The method according to claim 13 »characterized in that the bringing into contact of the vapors of the mixture in
Presence of added hydrogen gas makes. 15. The method according to claim 14, characterized in that R _{1 is} hydrogen, lower alkyl or phenyl. 16. The method according to claim 15 »characterized in that R _{2 is} hydrogen and R is hydrogen, alkyl having 1 to 4 carbon atoms or phenyl. 17. The method according to claim 16, characterized in that the catalyst is a cadmium copper bromite catalyst. 18. The method according to claim 17, characterized in that R is hydrogen. 19. The method according to claim 18, characterized in that R ₁ denotes phenyl. 20. The method according to claim 18, characterized in that R, means hydrogen. 0 0 9 8 19/1869 BATH