CA1218676A - Process for the preparation of a hydroxylamine - Google Patents
Process for the preparation of a hydroxylamineInfo
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- CA1218676A CA1218676A CA000469212A CA469212A CA1218676A CA 1218676 A CA1218676 A CA 1218676A CA 000469212 A CA000469212 A CA 000469212A CA 469212 A CA469212 A CA 469212A CA 1218676 A CA1218676 A CA 1218676A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Abstract
ABSTRACT
The present invention relates to a process for the preparation of organic hydroxylamines as a result of the corresponding nitroderivative being hy-drogenated in the presence of an inert solvent, a platinum catalyst, a nitrogen-containing base (in an amount of less than 10% by weight calcu-lated on the amount of nitro derivative) and a tri- or pentavalent organic phosphorus compound. It has been found that if only use is made of the nitrogen-containing base or the phosphorus compound the yields of isolated hydroxyl amine are significantly reduced in comparison with those obtained with the present process.
The present invention relates to a process for the preparation of organic hydroxylamines as a result of the corresponding nitroderivative being hy-drogenated in the presence of an inert solvent, a platinum catalyst, a nitrogen-containing base (in an amount of less than 10% by weight calcu-lated on the amount of nitro derivative) and a tri- or pentavalent organic phosphorus compound. It has been found that if only use is made of the nitrogen-containing base or the phosphorus compound the yields of isolated hydroxyl amine are significantly reduced in comparison with those obtained with the present process.
Description
The present invention relates to a proce~ for ~he preparation of a hy~
droxylamine of the formula A: R3 or ~: RNHOH
11 ~ 14 R ~ s NHOH
In co~pound A, the group3 R1, ~2, R~, R4 and Rs each represent a hydrogen atom, a hydroxy group, 8 halogen atom9 a llnear or branched-chain alkyl group having 1 to 20 carbon atom~, an alkoxy group havlng 1 to 20 carbon atoms, a cyclopentyl group, a cyclohexyl group9 a phenyl group, a phenyl~
alkyl or alkylphenyl group~ the alkyl group having 1 to 6 carbon atoms, or wherein t~o of the groups R1, R2, R3, R4 or Rs attached to ad~acent carbun atoms of the benzene ring together with the two carbon atoms of the benzené
rlng to which they are attached form a second benzene ring which is ortho-condensed with the first benzene ring. In compound B, the group R represents a linear or a brsnched-chain and/or cyclic alkyl group having l to 24 carbon atoms.
In so far 8S the Groups R1, - Rs or R arc hydrocarbon containing group~, they may have unsaturated bonds and may comprise substituents and groups such as amino, hydroxylamino, amido, cyano, hydroxy alkoxy, carboxyl, oxy-carbonyl, carboxy, sulphoxlde and ~ulphone. The groups R1 - R S or R may be combined to form part of a polymerlc structure.
The aromatic hydroxylamine A can be obtained by hydrogenation of the corre-~ponding nitro derivative in the presence of an inert ~olvent, a platinum cataly~t and ~ tri- or penta valent organ1c pho~phorous compound.
Such a process is known from Ch~m. Abstract~, 91, (1979~, 56604W, wherein i~
referred to Japane~e patent publication no. 7924837.
~0``1~
droxylamine of the formula A: R3 or ~: RNHOH
11 ~ 14 R ~ s NHOH
In co~pound A, the group3 R1, ~2, R~, R4 and Rs each represent a hydrogen atom, a hydroxy group, 8 halogen atom9 a llnear or branched-chain alkyl group having 1 to 20 carbon atom~, an alkoxy group havlng 1 to 20 carbon atoms, a cyclopentyl group, a cyclohexyl group9 a phenyl group, a phenyl~
alkyl or alkylphenyl group~ the alkyl group having 1 to 6 carbon atoms, or wherein t~o of the groups R1, R2, R3, R4 or Rs attached to ad~acent carbun atoms of the benzene ring together with the two carbon atoms of the benzené
rlng to which they are attached form a second benzene ring which is ortho-condensed with the first benzene ring. In compound B, the group R represents a linear or a brsnched-chain and/or cyclic alkyl group having l to 24 carbon atoms.
In so far 8S the Groups R1, - Rs or R arc hydrocarbon containing group~, they may have unsaturated bonds and may comprise substituents and groups such as amino, hydroxylamino, amido, cyano, hydroxy alkoxy, carboxyl, oxy-carbonyl, carboxy, sulphoxlde and ~ulphone. The groups R1 - R S or R may be combined to form part of a polymerlc structure.
The aromatic hydroxylamine A can be obtained by hydrogenation of the corre-~ponding nitro derivative in the presence of an inert ~olvent, a platinum cataly~t and ~ tri- or penta valent organ1c pho~phorous compound.
Such a process is known from Ch~m. Abstract~, 91, (1979~, 56604W, wherein i~
referred to Japane~e patent publication no. 7924837.
~0``1~
2 ~
Although a nitrogen contalning base 19 formed a3 a byproduct of the hydro-genation, due to a too rapid reduction of the~de~ired intermediate hydroxyl-amine~ there wa~ proposed for a long time to carry out ~he hydrogenation in the presence of an amount of an organic base to be added ~o the starting reaction mixture, llke in eg. US Patent Speciflca~ion 3927101. Hereln it l ~tated that in order to obtain sufficien~ly high yield~ of hydroxyla~ines, the ratio by weigh~ of the organic base to the nitro compound should be greater than O.l:l, preferably between 0.5:l and 5:1, Further di~closed is that the use of ~he base in trace amount~ does not make it po~sible to stop the hydrogenation at the hydroxylamlne stage.
After the hydrogenation reaction i9 completed, the organic base has to be removed. It has been observed that by using the above-mentioned high amount3 of organic bsse, problems might arlse upon isolating the hydrDxyl-amine.
It ha~ now been found that equivalent and even higher yields of hydroxyl-amine can be obtained with a pro2ess of ths above ~ype which is charactPr-ized in that the nitrogen-contsining base is added to the starting reaction mixture in an a~ount of le~3 than lOV~o by weight, calculated on ths a~ount of the nitro derlvative It has been found that if only use i9 made of the phosphoruY compound or the nltrogen-contalning base in an amoun~ of les~ than 10~/o by weight, cal-culated on the amount of nitro derlvative, the ylelds of isolated hydro-xylamine~ are significantly reduced in comparison with those obtained with the process in ~he present invention.
It should be added that Japanese patent publication No.30.096/82 discloses the use of trivalent pho3phorus compounds in reactions of the present type. However, this publication does not mention the present combination with the nitrogen-containing base in the starting reaction mixture.
Furthermore 9 U.S. 3 441 610 describes the catalytic hydrogenation of nitroalkanes to N-alkyl-hydroxylamineR. Use is made of a recovered pal-ladium catalyst and a cation of iron, nickel or cobalt in a two-phase liquid syste~ of aqueous sulphu~ic acid and an immi~cible organic solvent.
In such an acidic medium the 10~9 o catalyst will be considerable and the equipment may be subject to ~evere corrosion. Those dlsadvantages are cir-cumvented by the present inve~tion.
. \
6'76 The present invention rela~es to a process or the ~elective catalytic preparation of hydroxylamines with the structure A or B by selectlve cata].ytic hydrogenation of corresponding n-itro derivatives.
The problem known for a long tlme as associated with the use of platlnum-containing catalysts~ 1~ to preve~t tha nitro derivative~ from belng reduced to amines in the hydrogenatlon stage. The present process provlde~ such a proce3s without di~playing tlle di3advantages of similar, well-known proces-s~s.
Although a nitrogen contalning base 19 formed a3 a byproduct of the hydro-genation, due to a too rapid reduction of the~de~ired intermediate hydroxyl-amine~ there wa~ proposed for a long time to carry out ~he hydrogenation in the presence of an amount of an organic base to be added ~o the starting reaction mixture, llke in eg. US Patent Speciflca~ion 3927101. Hereln it l ~tated that in order to obtain sufficien~ly high yield~ of hydroxyla~ines, the ratio by weigh~ of the organic base to the nitro compound should be greater than O.l:l, preferably between 0.5:l and 5:1, Further di~closed is that the use of ~he base in trace amount~ does not make it po~sible to stop the hydrogenation at the hydroxylamlne stage.
After the hydrogenation reaction i9 completed, the organic base has to be removed. It has been observed that by using the above-mentioned high amount3 of organic bsse, problems might arlse upon isolating the hydrDxyl-amine.
It ha~ now been found that equivalent and even higher yields of hydroxyl-amine can be obtained with a pro2ess of ths above ~ype which is charactPr-ized in that the nitrogen-contsining base is added to the starting reaction mixture in an a~ount of le~3 than lOV~o by weight, calculated on ths a~ount of the nitro derlvative It has been found that if only use i9 made of the phosphoruY compound or the nltrogen-contalning base in an amoun~ of les~ than 10~/o by weight, cal-culated on the amount of nitro derlvative, the ylelds of isolated hydro-xylamine~ are significantly reduced in comparison with those obtained with the process in ~he present invention.
It should be added that Japanese patent publication No.30.096/82 discloses the use of trivalent pho3phorus compounds in reactions of the present type. However, this publication does not mention the present combination with the nitrogen-containing base in the starting reaction mixture.
Furthermore 9 U.S. 3 441 610 describes the catalytic hydrogenation of nitroalkanes to N-alkyl-hydroxylamineR. Use is made of a recovered pal-ladium catalyst and a cation of iron, nickel or cobalt in a two-phase liquid syste~ of aqueous sulphu~ic acid and an immi~cible organic solvent.
In such an acidic medium the 10~9 o catalyst will be considerable and the equipment may be subject to ~evere corrosion. Those dlsadvantages are cir-cumvented by the present inve~tion.
. \
6'76 The present invention rela~es to a process or the ~elective catalytic preparation of hydroxylamines with the structure A or B by selectlve cata].ytic hydrogenation of corresponding n-itro derivatives.
The problem known for a long tlme as associated with the use of platlnum-containing catalysts~ 1~ to preve~t tha nitro derivative~ from belng reduced to amines in the hydrogenatlon stage. The present process provlde~ such a proce3s without di~playing tlle di3advantages of similar, well-known proces-s~s.
-3~ 314 R
As organic phosphorus compound tri- Of pentavalent compounds can he used.
Trivalent phosphorus compounds are preferred. A class of suitable phos-phorus compounds includes trivalent compounds having aryl or arvloxy groups which may be substituted or not.
Preferably the aryl and aryloxy groups are phenyl and phenyloxy groups. As Examples of phosphorus compounds of this class may be mentioned triphenyl-phosphite~ dimethylphenylphosphite, triphenylphosphine, triphenylphospho-nite, tri-p-chlorophenylphosphonite, tri-p-nitrophenylphosphonite and tri-cresvlphosphonite.
Diphenylphosphite, di-p-chlorophenylphosphite, di-p-nitrophenylphosphite and di-p-methylphenylphosphite are also suitable phosphorus compounds.
A very suitable class includes phosphorus compounds having a~kyl or alkoxy group(s) containing l to 20 carbon atoms. Especiallv preferred are tri-alkylphosphines and tri-akylphosphites, with the alkyl group contalning 1 to 20 carbon atoms. EYamples thereof are: trimethylphospi-ine, tri-ethvl-phosphine, tri-isopropylphosphine, tri-butylphosphine, tri-octvlphosphine, tri-octaùecylphosphine, trimethylphosphite, tri-ethylphosphite, tri-iso-propylphosphite, tributylphosphite, trihexylphosphite, triheptyIphosphite, tri-octylphosphite, trinonylphosphite, tridecylphosphite and trilauryl-phosphite.
Most preferred thereof are compounds with alkvl groups having l to 6 car-bon atoms, special preference being given to tri-ethylphosphite, tri-iso-propvlphosphite and tributylphosphite.
Further phosphorus compounds which can be used in the present process are:
phosphorus trichloride, dimethylphosphochloridite, di-ethvlphosphochlor-idite, and he.Yamethylphosphoroustri-amide. In the last two compounds the functions of nitrogen-containing base and phosphorus compound are com-bined. If such compounds are used, the amount of a further nitrogen base may be reduced.
Of course, also mixtures of the above phosphorus compound can be used.
Generally, the reaction mixture should contain O.l to 5% by weight of the phosphorus compound, calculated on the amount of nitro derivative, pre-ferably 0 ? to 2.0/o and more particularly 0.3 to l.O~b by weight.
_4_ A(~ 4 R
Suitable nitro~en bases are ammonia, monoalkvlamineS, dialkylar~ines, tri-Qlkylamines, monoalkanolamines, dialkanol amines, trialkanol amines, rnono-, di- or tri-aryl amines, (poly)alkylene polyamines, pyrrolidine and piperidine substituted or not with 1 or ~ alkyl groups having 1 to 4 car-bon atoms and pyridines substituted or not with one or more alkyl, amino,phenylalkylamino, phenylamino or pyrrolidone groups. The ni.trogen base may contain primary, secondary and tertiary alkyl and/or alkanol groups.
Generally, the above-mentioned unspecified alkyl and alkanol groups may contain I to 20, preferably 1 to 6 and most preferably I to 4 carbon atoms.
E~amples of mono-, di- and trialkylamines are: methvlamine, ethYlamine, propvlamine, butylamine, pentylamine, hexylamine, hept-lamine, octylamine, nonylamine, octadecylamine, dimethylamine, diethylamine, dipropylamine, dipentylami.ne, dihexvlamine, diheptylamine, dioctylamine, didecylamine, clidodecylamine, dioctadecylamine, trimethylamine, triethylamine, tripro-pylamine, tri-isopropylamine, tributylamine, tripentylamine, trihe.Yyl-amine, triheptvlamine, tri-octylamine, tri-2-ethylhe~ylamine, tridecyl-amine and tri-octadecylamine.
Suitable mono-, di- and tri-alkanol amines are those having alkanol groups containing 1 to ~0 and preferably 1 to ~ carbon atoms. Examples thereof are ethanolamine, propanolamine, butanolamine, diethanolamine and tri-ethanolamine.
Suitable mono-, di- and tri-arylamines are N,N-cliethvl-N-phenylamine, N-ethyl-N,N-diphenvlamine, triphenyl.amine, tri-o-methylphenylamine, tri-m-methylphenylamine, tri-p-methylphenylamine, tri-benzylamine, N-benzyl-N,N-dimethylamine, N-benzyl-N,N-diethylamine, N-benzyl-~,N-di-isopropvl-amine, N-benzyl-~,N-di-n-butylamine and N-benzyl-N,N-di-tert.-butylamine.
Suitable (poly)alkylene polyamines are ethylenediamine, diethylenetri amine, triethylene tetra-amine, tetra-ethylene pentamine, penta-ethylene he~amlne.
Pyrrolidine and piperidine as well as substituted pyrrolidines and piper idines containing 1 or 2 alkyl groups with 1 to ~ carbon atoms can also be used. Preferred examples thereof are pyrrolidine, piperidine and mono-, di-, tri- and tetramethylpyrrolidines and piperidines.
;'76 Mos-t preferred are the pyridines substi-tuted or not with one or more alkyl, amino, phenyl, alkylamino, phenylamino or pyrrolidone groups, the alkyl groups containing preferably 1 to 6 carbon atoms.
Examples thereof are pyridine, N-methylpyridine, 2,6--dimethylpyridine, ~-methylethyl pyridine, 4-aminopyridine, 4-dimethylaminopyridine, 4-di-ethylaminopyridine, 4-dipropyl-aminopyridine, 4-dibutylaminopyridine and 4-diphenylamino-pyridine. Preference is given -to the dialkylamino pyridines, particularly to 4-dimethylaminoipyridine.
of course, also mixtures of the above nitrogen bases may be used. The reaction mixture should contain less than 10%
by weight of nitrogen base, calcula-ted on the amount o nitro derivative, generally 0.05 to 5%, preferably o.l to 2% and more particularly 0.2 to 1% of the nitrogen base.
The nitro derivative starting material has the formula C: R~ or D: RN02 R
R~\R~
NO~
In compound C, the groups Rl, R2, R3, R4 and R5 each represent a hydrogen atom, a hydroxy group, a halogen atom, a :Linear or branched-chain alkyl group having 1 to 20, preferably 1 to 6, carbon atoms, an alkoxy group having 1 to 20, preferably 1 to 6, carbon a-toms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a phenylalkyl or alkylphenyl group, the alkyl group having 1 to 6 carbon atoms, or wherein two of the groups Rl, R2, R3, R4 or R5 attached to adjacent carbon atoms of the ben~ene '7~
ring together with the two carbon atoms of the benzene ring which is orthocondensed wi-th the first benzene ring. In compound D, the group R represents a linear or a branched-chain and/or cyclic alkyl group having 1 to 24 carbon atoms 1.0 ~ - 5a ---6~ 8~ 7~ ~C~I l9l4 R
.
In so far as the groups Rl - Rs or ~ are hydrocarbon containing groups, they may have unsaturated bonds and may comprise substituents and groups such as amino, a~ido, nitro, nitroso, cyano, hydroxy, alkoxy, carbonyl, oxycarbonyl, carboxy, sulphoxide and sulphone. Ihe substituents may be combined to form part of a polymer structure.
Examples of aromatic nitro-derivatives are nitrobenzene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, p-isopropylnitrobenzene, m-butylnitroben-zene, 1,3-dimethyl-(2 or 4 or ;~nitrobenzene, 1,3,5-trimethyl-2-nitroben-zene, 4-nitro-biphenyl, para chloro nitrobenzene and (1 or 2 or 3~nitro-naphthalene. Preference i9 given to nitrobenzene.
E~amples of aliphati~ nitro compounds are nitroethane, nitropropane,2-metilyl-2-nitropropane, 9-nitro-9-methyl-1,6-decadiene.
The catalyst silould contain platinum and may or may not be deposited on a support. Suitable carrier materials are carbon blacks, alumina, silica, calcium carbonate, barium sulphate and the li~e.
When the platinum is on a carrier, the catalvst composition usually con-tains 0.1 to 20, preferablv 1 to lO;o of platinum. These catalyst can be prepared by methods well-known in the art. ~enerall~l the reaction mixture contains 0.001 to 5~O, preferably 0.01 to 1% by weight of platinum, calcu-lated on the amount of nitro derivative.
The hydrogenation reaction is usually carried out in the presence of aninert solvent. There is no limitation on the solvent used, provided that it does not react with the hydroxylamine formed. Suitable solvents are water, lower alcohols such as methanol, ethanol, propanol, isopropanol, aromatic and aliphatic hydrocarbons such as toluene and hexane. Preference is given to a lower alcohol. Mixtures of the ahove solvents can also be used~ The reaction mixture preferably contains 5 to 80~o by weight of sol-vent.
The selective hydrogenation reaction can be carried out at Ov to 150C, 30 preferably between 5 and 50C at a hydrogen pressure of 10 to 2000 kPa, preferably 100 to 500 kPa.
, The present invention will be illustrated with the following examples.
7~
~ CH 1~314 R
Exa~le 1 A solution of nitrobenzene (~4.6 g) in 80 ml of methanol is charged into a 600 ml autoclave; and 0.33 g of a catalyst based on platinum and carbon black contalning 3% of platinum is added. 0.1 g of 4-dimethylamino pyri-dine and 0.25 g of tributylphosphite are then added to the autoclave. Theautoclave is tilen sealed and deaerated using a vacuum pump. Next, hydro-genation is carried out at 10C at 414 kPa for 3/4 ho-lrs after which time the theoretical amount of i)ydrogen was absorbed. After filtration of the Pt/C catalyst, the filtrate is evaporated bv using a rotarv evaporatnr under vacuum at 45-5~C (bath temperature), after wllich the final traces of the solvent are removed using an oil pump. There are obtained 20.3 g of crude phenylhvdroxylamine. The crude material is then treate~ with 75 ml of heYane, after which the mixtu}e is well agitated and filtered. Final-ly, there are obtained 17.7 g of pure phenylhydro~ylamine lviel~ 81.2'h, m.p. 81C, correct IR and NMR).
Comparative E~ample A
__ __ _ Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenation is carried oot in the absence of 4-dime-thvlaminopyridine.
Nitrobenzene 12.3 g Methanol 40 ml Tri-ethvlphosphite 0.322 g 3`~ Pt/C 0-400 g Pressure of Hvdrogen 414 kPa Temperature 10 ~C
Time 1 3/4 hours Finally, there are obtained 9.4 g of an oil which does not crystallize to give phenylhydroxylamine. The same results were obtained by using 0.25 g of tributylphosphite instead of triethylphosphite.
Comparfl~.ive Example B
Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenation is carried out in the absence of a trial-kyl phosphite:
-8~ 3~ 76 ~(~1 19l4 R
. .
Nitrobenzene 24.6 g Methanol 80 ml
As organic phosphorus compound tri- Of pentavalent compounds can he used.
Trivalent phosphorus compounds are preferred. A class of suitable phos-phorus compounds includes trivalent compounds having aryl or arvloxy groups which may be substituted or not.
Preferably the aryl and aryloxy groups are phenyl and phenyloxy groups. As Examples of phosphorus compounds of this class may be mentioned triphenyl-phosphite~ dimethylphenylphosphite, triphenylphosphine, triphenylphospho-nite, tri-p-chlorophenylphosphonite, tri-p-nitrophenylphosphonite and tri-cresvlphosphonite.
Diphenylphosphite, di-p-chlorophenylphosphite, di-p-nitrophenylphosphite and di-p-methylphenylphosphite are also suitable phosphorus compounds.
A very suitable class includes phosphorus compounds having a~kyl or alkoxy group(s) containing l to 20 carbon atoms. Especiallv preferred are tri-alkylphosphines and tri-akylphosphites, with the alkyl group contalning 1 to 20 carbon atoms. EYamples thereof are: trimethylphospi-ine, tri-ethvl-phosphine, tri-isopropylphosphine, tri-butylphosphine, tri-octvlphosphine, tri-octaùecylphosphine, trimethylphosphite, tri-ethylphosphite, tri-iso-propylphosphite, tributylphosphite, trihexylphosphite, triheptyIphosphite, tri-octylphosphite, trinonylphosphite, tridecylphosphite and trilauryl-phosphite.
Most preferred thereof are compounds with alkvl groups having l to 6 car-bon atoms, special preference being given to tri-ethylphosphite, tri-iso-propvlphosphite and tributylphosphite.
Further phosphorus compounds which can be used in the present process are:
phosphorus trichloride, dimethylphosphochloridite, di-ethvlphosphochlor-idite, and he.Yamethylphosphoroustri-amide. In the last two compounds the functions of nitrogen-containing base and phosphorus compound are com-bined. If such compounds are used, the amount of a further nitrogen base may be reduced.
Of course, also mixtures of the above phosphorus compound can be used.
Generally, the reaction mixture should contain O.l to 5% by weight of the phosphorus compound, calculated on the amount of nitro derivative, pre-ferably 0 ? to 2.0/o and more particularly 0.3 to l.O~b by weight.
_4_ A(~ 4 R
Suitable nitro~en bases are ammonia, monoalkvlamineS, dialkylar~ines, tri-Qlkylamines, monoalkanolamines, dialkanol amines, trialkanol amines, rnono-, di- or tri-aryl amines, (poly)alkylene polyamines, pyrrolidine and piperidine substituted or not with 1 or ~ alkyl groups having 1 to 4 car-bon atoms and pyridines substituted or not with one or more alkyl, amino,phenylalkylamino, phenylamino or pyrrolidone groups. The ni.trogen base may contain primary, secondary and tertiary alkyl and/or alkanol groups.
Generally, the above-mentioned unspecified alkyl and alkanol groups may contain I to 20, preferably 1 to 6 and most preferably I to 4 carbon atoms.
E~amples of mono-, di- and trialkylamines are: methvlamine, ethYlamine, propvlamine, butylamine, pentylamine, hexylamine, hept-lamine, octylamine, nonylamine, octadecylamine, dimethylamine, diethylamine, dipropylamine, dipentylami.ne, dihexvlamine, diheptylamine, dioctylamine, didecylamine, clidodecylamine, dioctadecylamine, trimethylamine, triethylamine, tripro-pylamine, tri-isopropylamine, tributylamine, tripentylamine, trihe.Yyl-amine, triheptvlamine, tri-octylamine, tri-2-ethylhe~ylamine, tridecyl-amine and tri-octadecylamine.
Suitable mono-, di- and tri-alkanol amines are those having alkanol groups containing 1 to ~0 and preferably 1 to ~ carbon atoms. Examples thereof are ethanolamine, propanolamine, butanolamine, diethanolamine and tri-ethanolamine.
Suitable mono-, di- and tri-arylamines are N,N-cliethvl-N-phenylamine, N-ethyl-N,N-diphenvlamine, triphenyl.amine, tri-o-methylphenylamine, tri-m-methylphenylamine, tri-p-methylphenylamine, tri-benzylamine, N-benzyl-N,N-dimethylamine, N-benzyl-N,N-diethylamine, N-benzyl-~,N-di-isopropvl-amine, N-benzyl-~,N-di-n-butylamine and N-benzyl-N,N-di-tert.-butylamine.
Suitable (poly)alkylene polyamines are ethylenediamine, diethylenetri amine, triethylene tetra-amine, tetra-ethylene pentamine, penta-ethylene he~amlne.
Pyrrolidine and piperidine as well as substituted pyrrolidines and piper idines containing 1 or 2 alkyl groups with 1 to ~ carbon atoms can also be used. Preferred examples thereof are pyrrolidine, piperidine and mono-, di-, tri- and tetramethylpyrrolidines and piperidines.
;'76 Mos-t preferred are the pyridines substi-tuted or not with one or more alkyl, amino, phenyl, alkylamino, phenylamino or pyrrolidone groups, the alkyl groups containing preferably 1 to 6 carbon atoms.
Examples thereof are pyridine, N-methylpyridine, 2,6--dimethylpyridine, ~-methylethyl pyridine, 4-aminopyridine, 4-dimethylaminopyridine, 4-di-ethylaminopyridine, 4-dipropyl-aminopyridine, 4-dibutylaminopyridine and 4-diphenylamino-pyridine. Preference is given -to the dialkylamino pyridines, particularly to 4-dimethylaminoipyridine.
of course, also mixtures of the above nitrogen bases may be used. The reaction mixture should contain less than 10%
by weight of nitrogen base, calcula-ted on the amount o nitro derivative, generally 0.05 to 5%, preferably o.l to 2% and more particularly 0.2 to 1% of the nitrogen base.
The nitro derivative starting material has the formula C: R~ or D: RN02 R
R~\R~
NO~
In compound C, the groups Rl, R2, R3, R4 and R5 each represent a hydrogen atom, a hydroxy group, a halogen atom, a :Linear or branched-chain alkyl group having 1 to 20, preferably 1 to 6, carbon atoms, an alkoxy group having 1 to 20, preferably 1 to 6, carbon a-toms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a phenylalkyl or alkylphenyl group, the alkyl group having 1 to 6 carbon atoms, or wherein two of the groups Rl, R2, R3, R4 or R5 attached to adjacent carbon atoms of the ben~ene '7~
ring together with the two carbon atoms of the benzene ring which is orthocondensed wi-th the first benzene ring. In compound D, the group R represents a linear or a branched-chain and/or cyclic alkyl group having 1 to 24 carbon atoms 1.0 ~ - 5a ---6~ 8~ 7~ ~C~I l9l4 R
.
In so far as the groups Rl - Rs or ~ are hydrocarbon containing groups, they may have unsaturated bonds and may comprise substituents and groups such as amino, a~ido, nitro, nitroso, cyano, hydroxy, alkoxy, carbonyl, oxycarbonyl, carboxy, sulphoxide and sulphone. Ihe substituents may be combined to form part of a polymer structure.
Examples of aromatic nitro-derivatives are nitrobenzene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, p-isopropylnitrobenzene, m-butylnitroben-zene, 1,3-dimethyl-(2 or 4 or ;~nitrobenzene, 1,3,5-trimethyl-2-nitroben-zene, 4-nitro-biphenyl, para chloro nitrobenzene and (1 or 2 or 3~nitro-naphthalene. Preference i9 given to nitrobenzene.
E~amples of aliphati~ nitro compounds are nitroethane, nitropropane,2-metilyl-2-nitropropane, 9-nitro-9-methyl-1,6-decadiene.
The catalyst silould contain platinum and may or may not be deposited on a support. Suitable carrier materials are carbon blacks, alumina, silica, calcium carbonate, barium sulphate and the li~e.
When the platinum is on a carrier, the catalvst composition usually con-tains 0.1 to 20, preferablv 1 to lO;o of platinum. These catalyst can be prepared by methods well-known in the art. ~enerall~l the reaction mixture contains 0.001 to 5~O, preferably 0.01 to 1% by weight of platinum, calcu-lated on the amount of nitro derivative.
The hydrogenation reaction is usually carried out in the presence of aninert solvent. There is no limitation on the solvent used, provided that it does not react with the hydroxylamine formed. Suitable solvents are water, lower alcohols such as methanol, ethanol, propanol, isopropanol, aromatic and aliphatic hydrocarbons such as toluene and hexane. Preference is given to a lower alcohol. Mixtures of the ahove solvents can also be used~ The reaction mixture preferably contains 5 to 80~o by weight of sol-vent.
The selective hydrogenation reaction can be carried out at Ov to 150C, 30 preferably between 5 and 50C at a hydrogen pressure of 10 to 2000 kPa, preferably 100 to 500 kPa.
, The present invention will be illustrated with the following examples.
7~
~ CH 1~314 R
Exa~le 1 A solution of nitrobenzene (~4.6 g) in 80 ml of methanol is charged into a 600 ml autoclave; and 0.33 g of a catalyst based on platinum and carbon black contalning 3% of platinum is added. 0.1 g of 4-dimethylamino pyri-dine and 0.25 g of tributylphosphite are then added to the autoclave. Theautoclave is tilen sealed and deaerated using a vacuum pump. Next, hydro-genation is carried out at 10C at 414 kPa for 3/4 ho-lrs after which time the theoretical amount of i)ydrogen was absorbed. After filtration of the Pt/C catalyst, the filtrate is evaporated bv using a rotarv evaporatnr under vacuum at 45-5~C (bath temperature), after wllich the final traces of the solvent are removed using an oil pump. There are obtained 20.3 g of crude phenylhvdroxylamine. The crude material is then treate~ with 75 ml of heYane, after which the mixtu}e is well agitated and filtered. Final-ly, there are obtained 17.7 g of pure phenylhydro~ylamine lviel~ 81.2'h, m.p. 81C, correct IR and NMR).
Comparative E~ample A
__ __ _ Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenation is carried oot in the absence of 4-dime-thvlaminopyridine.
Nitrobenzene 12.3 g Methanol 40 ml Tri-ethvlphosphite 0.322 g 3`~ Pt/C 0-400 g Pressure of Hvdrogen 414 kPa Temperature 10 ~C
Time 1 3/4 hours Finally, there are obtained 9.4 g of an oil which does not crystallize to give phenylhydroxylamine. The same results were obtained by using 0.25 g of tributylphosphite instead of triethylphosphite.
Comparfl~.ive Example B
Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenation is carried out in the absence of a trial-kyl phosphite:
-8~ 3~ 76 ~(~1 19l4 R
. .
Nitrobenzene 24.6 g Methanol 80 ml
4-dimethylaminopyridine 2 g 3% PtlC 0.4 g Pressure of Hydrogen 414 kPa Temperature 10 C
Time 11/2 hours Finally, there are obtained 21 g of an oil which upon treatment with hexane (100 ml? followed by cooling to -30C gives 10 g of cryst~lline phenylhydroxylamine. (Yield 45.9'~, m.p. 80C).
E~ le 2 The effects of adding different combinations of phosphorus compound and organic base was evaluated as follows: The general method was the same as in Example 1, e~cept that the organic base and phosphorus component were varied as given in the following table. For this experiment the hvdrogen pressure was maintained at 212 kPa and the final reaction mi~ture ana-lysed~ using gas liquid chromatography.
Table 1 _ _ _ _ _ _ Triethylphosphite I Productcomposition(g) ~ TEP) I Phe~y~ droxylamine~PHA) 20 I L,evel I Ba~e(g~ I Nitroben~ene I Aniline I PHA I `iO~ield L ~ TEP) ~ ~ l l I ofP~ ¦
0.17 g I I ~-7 1 3-4 1 13.8 1 71 0.17 g I D~P O.OSI 0.4 1 2.2 1 18.8 1 87.7 1 0.17 g I D~P 0.1 1 1.3 1 1.9 1 17.6 1 85.2 25 1 0 17 g ¦ Pyridine 0.1 1 5.3 ~ 1.3 1 13.2 L 76 _ _ _ _ _ _ _ _ _ _ _ _ _ Triphenylphosphine (TPP) _ l _ _ _ _ Level ¦ Base I TPP
30 1 0.17 g I 1 4.4 1 1.1 114.2 1 78 L_17 g I DMAP ~ 2.3 11~ 6 1 _ 85 __L
D~AP = dimethylaminopyridine _9~ CI~ 19l4 R
E~ample 3 Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenation is carried out as described before:
2-Nitrotoluene27.42 g Methanol 80 ml 4-DMAP 0.1 g Tributylphosphite 0.250 g 3% Pt/C 0.33 g Pressure of hydrogen 212 ~Pa Temperature 32 C
Time 4.0 hours There are obtained 21.8 g of an oil, which upon treatment with hexane (lO0 ml) followed by cooling to about -30C gives 14.76 g of N-o-tolylhydro~yl-amine ~Yield 60%, m.p. 44C, correct IR and NMR spectrum).
Example 4 Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenatioll is carried out as described before:
4-Nitrotoluene27.42 g Methanol 80 ml 4-DMAP 0.1 g Tributylphosphite 0.25 g 3%Pt/C 0.33 g Pressure of Hydrogen 212 kPa Temperature 25 C
Time 1 hours There are obtained 24.5 g of an oil, which upon treatment with he~ane (100 ml) followed by cooling to about -30C gives 14.2 g of N-~p-tolyl) hydroxylamine (Yield 57.7%, m.p. 98-99C, correct IR and NMR spectrum).
_~ample 5 Using the following amounts of starting materials and slmilar conditions as in Example 1, hydrogenation is carried out a5 described before:
-'~ 7~ ~( H 1)14 R
p-chloro Nitrobenzene 31.51 Methanol 80 ml 4-DMAP 0.1 g Tributylphosphite 0.25 g 3/~ Pt/C 0.33 a Pressure of Hydrogen 414 kPa Temperature25 C
Time 2 hours There are obtained 25.2 g of an oil, which upnn treatment with he~ane (125 ml) followed by cooling to about -30~C gi-es 18.52 ~ of p-chloro phenyl-hydroxylamine (YielA 64.5~, m.p. 83-84C, correct IR and N~ spectrum).
E~ample 6 ~sing the following amounts of starting materials and similar conditions as in e~ample 17 hydrogellation was carried out as described before:
15 l-Nitropropane17.82 g triethylamine0.10 g triethylphosphite 0.166 o 3~/~ Pt/C 0.33 g pressure of hvdrogen 345 kPa 20 temperature 40 C
reaction timeabout 5l6 hours Ihe crude mi~ture was filtered and Pt/C removed for :~ny subsequent use.
The organic layer was treated with conc. HCl and cooled below ambient tem-perature where N-(1-propyl)hydro~ylamine hvdrochloride (1/.84g) was ob-tained in 80`h yield.
E~am ~
~sing the following amounts of starting materials and similar conditionsas given in E~ample 1, the hydrogenation of 1-nitropropane, 2-nitropro-pane, 2-methyl-2-nitropropane and 9-methyl-9-nitro-1,6-decadiene is car-ried out as described before:
~ 7~ l4 ~
aliphatic nitro compound 0.2 mo:les 4-dimethylamino pyridine 0,1 g tributyl phosphite 0,25 g 3:'h pt/C0,33 g pressure of hydrogen 414 kPa temperature40 C
reaction timeabout 3/4 hours The crude material i~ treated with 75 ml ot hexane, followed by igorous agitation and subseql~ent filtration. The yields ot ~-(l-propyl)hydro~vl-amine, N-~2-propyl) hydro~ylamine, N-(~-methylprop~l) hvdroxylamine and 9-hydroxyl-amino-9-methvl-1,6-decadiene from 1-nitropropane, 2-nitropro-pane, 2-methyl-2-nitropropane and 9-methyl-9-nitro-1,6-decadiene ~re ~0, 67, 67 and 60`io ~ respectively.
Time 11/2 hours Finally, there are obtained 21 g of an oil which upon treatment with hexane (100 ml? followed by cooling to -30C gives 10 g of cryst~lline phenylhydroxylamine. (Yield 45.9'~, m.p. 80C).
E~ le 2 The effects of adding different combinations of phosphorus compound and organic base was evaluated as follows: The general method was the same as in Example 1, e~cept that the organic base and phosphorus component were varied as given in the following table. For this experiment the hvdrogen pressure was maintained at 212 kPa and the final reaction mi~ture ana-lysed~ using gas liquid chromatography.
Table 1 _ _ _ _ _ _ Triethylphosphite I Productcomposition(g) ~ TEP) I Phe~y~ droxylamine~PHA) 20 I L,evel I Ba~e(g~ I Nitroben~ene I Aniline I PHA I `iO~ield L ~ TEP) ~ ~ l l I ofP~ ¦
0.17 g I I ~-7 1 3-4 1 13.8 1 71 0.17 g I D~P O.OSI 0.4 1 2.2 1 18.8 1 87.7 1 0.17 g I D~P 0.1 1 1.3 1 1.9 1 17.6 1 85.2 25 1 0 17 g ¦ Pyridine 0.1 1 5.3 ~ 1.3 1 13.2 L 76 _ _ _ _ _ _ _ _ _ _ _ _ _ Triphenylphosphine (TPP) _ l _ _ _ _ Level ¦ Base I TPP
30 1 0.17 g I 1 4.4 1 1.1 114.2 1 78 L_17 g I DMAP ~ 2.3 11~ 6 1 _ 85 __L
D~AP = dimethylaminopyridine _9~ CI~ 19l4 R
E~ample 3 Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenation is carried out as described before:
2-Nitrotoluene27.42 g Methanol 80 ml 4-DMAP 0.1 g Tributylphosphite 0.250 g 3% Pt/C 0.33 g Pressure of hydrogen 212 ~Pa Temperature 32 C
Time 4.0 hours There are obtained 21.8 g of an oil, which upon treatment with hexane (lO0 ml) followed by cooling to about -30C gives 14.76 g of N-o-tolylhydro~yl-amine ~Yield 60%, m.p. 44C, correct IR and NMR spectrum).
Example 4 Using the following amounts of starting materials and similar conditions as in Example 1, hydrogenatioll is carried out as described before:
4-Nitrotoluene27.42 g Methanol 80 ml 4-DMAP 0.1 g Tributylphosphite 0.25 g 3%Pt/C 0.33 g Pressure of Hydrogen 212 kPa Temperature 25 C
Time 1 hours There are obtained 24.5 g of an oil, which upon treatment with he~ane (100 ml) followed by cooling to about -30C gives 14.2 g of N-~p-tolyl) hydroxylamine (Yield 57.7%, m.p. 98-99C, correct IR and NMR spectrum).
_~ample 5 Using the following amounts of starting materials and slmilar conditions as in Example 1, hydrogenation is carried out a5 described before:
-'~ 7~ ~( H 1)14 R
p-chloro Nitrobenzene 31.51 Methanol 80 ml 4-DMAP 0.1 g Tributylphosphite 0.25 g 3/~ Pt/C 0.33 a Pressure of Hydrogen 414 kPa Temperature25 C
Time 2 hours There are obtained 25.2 g of an oil, which upnn treatment with he~ane (125 ml) followed by cooling to about -30~C gi-es 18.52 ~ of p-chloro phenyl-hydroxylamine (YielA 64.5~, m.p. 83-84C, correct IR and N~ spectrum).
E~ample 6 ~sing the following amounts of starting materials and similar conditions as in e~ample 17 hydrogellation was carried out as described before:
15 l-Nitropropane17.82 g triethylamine0.10 g triethylphosphite 0.166 o 3~/~ Pt/C 0.33 g pressure of hvdrogen 345 kPa 20 temperature 40 C
reaction timeabout 5l6 hours Ihe crude mi~ture was filtered and Pt/C removed for :~ny subsequent use.
The organic layer was treated with conc. HCl and cooled below ambient tem-perature where N-(1-propyl)hydro~ylamine hvdrochloride (1/.84g) was ob-tained in 80`h yield.
E~am ~
~sing the following amounts of starting materials and similar conditionsas given in E~ample 1, the hydrogenation of 1-nitropropane, 2-nitropro-pane, 2-methyl-2-nitropropane and 9-methyl-9-nitro-1,6-decadiene is car-ried out as described before:
~ 7~ l4 ~
aliphatic nitro compound 0.2 mo:les 4-dimethylamino pyridine 0,1 g tributyl phosphite 0,25 g 3:'h pt/C0,33 g pressure of hydrogen 414 kPa temperature40 C
reaction timeabout 3/4 hours The crude material i~ treated with 75 ml ot hexane, followed by igorous agitation and subseql~ent filtration. The yields ot ~-(l-propyl)hydro~vl-amine, N-~2-propyl) hydro~ylamine, N-(~-methylprop~l) hvdroxylamine and 9-hydroxyl-amino-9-methvl-1,6-decadiene from 1-nitropropane, 2-nitropro-pane, 2-methyl-2-nitropropane and 9-methyl-9-nitro-1,6-decadiene ~re ~0, 67, 67 and 60`io ~ respectively.
Claims (13)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the preparation of a hydroxylamine of the formula A: or B: RNHOH
in which R1, R2, R3, R4 and R5 each represent a hydrogen atom, a hy-droxy group, a halogen atom, a linear or branched-chain alkyl group having l to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a phenylalkyl or alkylphenyl group, the alkyl group having 1 to 6 carbon atoms, or wherein two of the groups R1, R2, R3, R4 or R5 attached to adjacent carbon atoms of the benzene ring together with the two carbon atoms of the benzene ring to which they are attached from a second benzene ring which is ortho-condensed with the first benzene ring, and R
represents a linear or a branched-chain and/or cyclic alkyl group having 1 to 24 carbon atoms, by conversion of the corresponding nitro deriva-tive by hydrogenation in the presence of an inert solvent, a platinum catalyst and a tri- or penta valent organic, phosphorous compound charac-terized in that a nitrogen containing base has been added to the starting reaction mixture in an amount of less than 10% by weight, cal-culated on the amount of the nitro derivative.
in which R1, R2, R3, R4 and R5 each represent a hydrogen atom, a hy-droxy group, a halogen atom, a linear or branched-chain alkyl group having l to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a phenylalkyl or alkylphenyl group, the alkyl group having 1 to 6 carbon atoms, or wherein two of the groups R1, R2, R3, R4 or R5 attached to adjacent carbon atoms of the benzene ring together with the two carbon atoms of the benzene ring to which they are attached from a second benzene ring which is ortho-condensed with the first benzene ring, and R
represents a linear or a branched-chain and/or cyclic alkyl group having 1 to 24 carbon atoms, by conversion of the corresponding nitro deriva-tive by hydrogenation in the presence of an inert solvent, a platinum catalyst and a tri- or penta valent organic, phosphorous compound charac-terized in that a nitrogen containing base has been added to the starting reaction mixture in an amount of less than 10% by weight, cal-culated on the amount of the nitro derivative.
2. A process according to claim 1, characterized in that the hydroxylamine has the A structure.
3. A process according to claim 2, characterized in that the hydroxylamine has the B structure.
4. A process according to claim 1, 2 or 3 characterized in that the phos-phorus compound contains at least one alkylgroup having 1 to 20 carbon atoms, or at least one aryl or aryloxy group.
5. A process according to claim 1 characterized in that the phosphorus compound is triphenylphosphine and/or tri-phenylphosphite,
6. A process according to claim 1 characterized in that the phosphorus compound is a trialkyl phosphine and/or tri-alkyl phosphite.
7. A process according to claim 6, characterized in that the phosphorus compound is a trialkyl phosphite, with the alkyl groups containing 1 to 6 carbon atoms.
8. A process according to claim 7, characterized in that the phosphorus compound is triethylphosphite, tripropylphos-phite and/or tributylphosphite.
9. A process according to claim 1, characterized in that the nitrogen-containing base is a di- or tri-alkyl amine, with the alkyl groups containing 1 to 6 carbon atoms.
10. A process according to claim 9, characterized in that the nitrogen containing base is triethylamine.
11. A process according to claim 1 characterized in that the nitrogen-containing base is pyridine substituted or not with one or more alkyl, amino, phenyl, alkylamino, phenylamino or pyrrolidone groups, the alkyl groups containing 1 to 6 carbon atoms.
12. A process according to claim 11, characterized in that the nitrogen containing base is dialkylaminopyridine.
13. A process according to claim 12, characterized in that the nitrogen containing base is a dimethylaminopyridine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB838332555A GB8332555D0 (en) | 1983-12-06 | 1983-12-06 | Preparation of aromatic hydroxylamine |
| GB8332555 | 1983-12-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1218676A true CA1218676A (en) | 1987-03-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000469212A Expired CA1218676A (en) | 1983-12-06 | 1984-12-03 | Process for the preparation of a hydroxylamine |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS60139649A (en) |
| CA (1) | CA1218676A (en) |
| GB (1) | GB8332555D0 (en) |
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| CN101663265B (en) * | 2007-03-27 | 2016-06-08 | 和光纯药工业株式会社 | The manufacture method of aryl-hydroxy amine |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| ZA83304B (en) * | 1982-01-29 | 1983-10-26 | Mallinckrodt Inc | Process for the preparation of arylhydroxylamines |
-
1983
- 1983-12-06 GB GB838332555A patent/GB8332555D0/en active Pending
-
1984
- 1984-12-03 CA CA000469212A patent/CA1218676A/en not_active Expired
- 1984-12-06 JP JP59256599A patent/JPS60139649A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| GB8332555D0 (en) | 1984-01-11 |
| JPH0469626B2 (en) | 1992-11-06 |
| JPS60139649A (en) | 1985-07-24 |
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