DEP0043097DA - Process for the production of amines - Google Patents

Description

Process for the preparation of amines.

The subject of the present invention is a new process ?, \ Xv Production of amines from amides with the same number of carbon atoms.

Ks is known j Säureamlde eg convert by-Hofmann'sehen reduction in amines _o one carbon atom less than the included Ausgangsamide have been described in the literature already several methods which Amid® ZM amines with the same Ansah! can be reduced by carbon atoms. This reduction is achieved on a catalytic basis when using copper chromium oxide catalysts at 200-300 atmospheres and approx can also be reduced electrolytically to amines [Pr, Fichter _f "Organische Elektrochemie", S ₀ 265 ff., (1942}]). The known methods are often unsatisfactory, however, since energetic conditions are required

which give rise to weaving reactions. In many cases it is also completely impossible to use the known Amid © to reduce the desired amines at all "

It has now been found that amines are obtained in a precautionary manner if a carboxylic acid amide is used with Lithium = aluminum hydride reduced.

Unsubstituted or substituted Amid® aliphatic alicyclic, aromatic, araliphatic * or heterocyclic carboxylic acids can be used as starting materials. The amide group can be the residue of an open amide or, as in the cyclic amides, form part of a ring, as in lactams, for example in 2-pyridones or 2-ghinolones, furthermore in dicarboximides, e.g. phthaliraids or quinolineimides. The acid residue of © sur reduction amides used may also be substituted _5, for example, by free or etherified oxy © or by another amide groups, with polyamines are obtained.

The reduction is preferably carried out in the presence of an indifferent waa. free organic solvent in which the lithium-aluminum hydride is soluble, especially in the presence of ether, but also of tetrahydrofuran, butyl ether, bioxane and the like. Particularly good results are obtained with amides, the · * «diluents used are easily soluble»

Under the new method, it is possible to win Amin® very easy © way au di © or are obtainable by known methods not so easy at all, so SoB * AlNiN © connected ₈ whose nitrogen atom with three different organic radicals _o A The great advantage of this process is that it works at a low temperature and thus undesirable side reactions are wasted ο Usually present® carbon multiple bonds are not reduced. Through a suitable choice of the reaction conditions, for example through the use of larger amounts of the reducing agent, longer exposure time and increased temperature, double bonds that are present in certain cases, especially those in cc [ß = position /.· to the amide group _? be satiated.

Amines obtainable by the present process can be used in a wide variety of fields.

The invention is described in more detail in the following examples, with between parts by weight and VoI, »part the same definition as between grams around. ' Cubic centimeter. The temperatures are given in degrees Celsius.

Example 1:

Triethylamine

9 _S 5 Gewe-I'öilo Lithium-Alurainium-Hydrid are dissolved in 360 parts by volume of absolute ether; 23 parts by weight of Ν, Ν-Biäthyl ^ acetSEid, dissolved in 300 parts by volume of abs. Ether _s in an "at such a rate that the solution will keep the liquid gently boiling ge =" After the end of reduction is sur added reaction mixture water, acidified with sulfuric acid and hiert rait ether to remove the acidic and neuter-len reaction products Extra "=. It is then made strongly alkaline with 10-fnO / water hydroxide solution and extracted again with ether. From the ether extract

the triethylamine is obtained from bp S9 ° o

Example 2:

Ethyl propylamine;

To 19 parts by weight of lithium ~ AlUfflinium ~ hydride in 720 volts, = parts of abs. Ether are 44 parts by weight of propionic acid ethylamide in 600 Volf-Tjjlen abs. Aether added. When the reaction has ended, it is worked up analogously to Example 1 and the ethyl propylamine with a boiling point of ₀ 78 ° is obtained. Its hydrochloride melts at 222-223 °.

Example 3:

β-ethyl butylamine;

To 1 ^ 03 Gem. parts Lit.hium ~ ~ aluminum Hyarid solved VoI. parts abs in BO. Aether, is added within 1-2 hours 2 45 parts by weight of a-Ethyi-crotonsaureamid in 400 VolI "parts abs" Aether and then it is kept at a gentle boil for about 20 hours "The reaction mixture is then replaced with water and acidified" first is extracted with ether _s makes with sodium hydroxide solution strongly alkaline and again extracted rait ether. The ethereal solution gives d ^ s- ß-ethyl-butylamine, which boils at / Ti *? ^ And forms a picrate with a melting point of 160 = 169 °.

Example 4 »

β "Phenoxy ~ ethylam inj_

Abs to a solution of 4 $ 6 parts by weight of lithium aluminum hydride in 600 VoI ₀ "parts., Ether allowed to 6 ₈ 9 parts by weight in phenoxyacetamide d ^ et» i / ice are added dropwise, the solution boils slightly . After the reaction has ended, the mixture is set with water and the reaction mass acidified with sulfuric acid is extracted with ether. It is then made alkaline and extracted again with ether. The ether extract gives tea, phenoxyethylamine of boiling point ₀ . 104 °. His picrate has the ^> mp _e of 167 ~ 168 ⁰ =

Example 5;

(3 f 4. 5 ° Trim @ thoxy "benzyl)

Analogously to Example 4, 3,4> 5 »-trimeth-oxy-benzoic acid-dimethylamide is obtained from 12 parts by weight by reduction with 4j6% by weight lithium aluminum hydride eh »N - ^^ jS-trimethoxybenzyl) -> dimethylamine of b.p., q 154 * = 155 and its picrate from it from smpo 146-147 °.

Example 6:

β -Pheny l ° -ä thy lami η:

4.5 parts by weight of lithium-aluminum hydride are dissolved in 500 parts by weight of absolute ether and placed in an extraction thimble with 13.5 parts by weight of phenylacetamide. Heat the ethereal solution as long as _s is extracted until all Phenylacetainid. On that

is worked up as in the above examples and one obtains <La & p-phenyl-ethylamine of b.p. ^ ₂ 70-80 °, the picrate of which cuddles at 167-160 °.

Example 7:

Iso ^ indoline:

Analog -. > previous example, 9 _s 0 parts by weight of lithium "= aluminum = hydride in 600? olo = -T @ il © n abs. Dissolved ether and 14 _s 7 parts by weight of phthalimide in the extraction «

sleeve given. During the extraction, the contents of the flask turn brown = black. After working up the reaction mixture one obtains isofindoline of b.p., q 92 °; its picrate forms fine girls that melt at 192-193 °.

Example Ö:

To 4i. 54 GeWo parts of lithium aluminum hydride in 300 parts by volume of absolute ether are left with 0.95 parts by weight of N-acetyl

K de £ ahydroisoquin.olin, dissolved in 300 parts by volume of abs. Ether, slowly drop in so that the ether boils gently. After the reaction has ended, work-up is carried out analogously to the above examples

k and is obtained as "N-ethyl-de ^ ahydroisochinolin, bp., ^ 92 = 94 °. It forms a hydrochloric! ν cm m.p. 203-204 °.

Example 9:

2,3-bis

To 14j2 parts by weight of lithium aluminum hydride in 300 parts of abs. The solution of 30 parts by weight of ghinolinic acid bis = benayl-ethylamide in 300 parts by volume of absolute ether is allowed to flow into ether it is warmed up on the water bath for another 22 hours. After usual work-up d®x receives a n rs Fairy 2,3-bis (N-ethyl ~ N-benzyl

arainomethyl) pyridine as a colorless oil with a b.p. « ₂ 7Ö => 80 °. The hydrochloride melts at

Example 10:

1.2. _fn 3, 4-tetrahydro. °> isoquinoline:

14 _? 7 parts by weight of laodihydrocarbostiyril dissolved in 300 parts by volume of abs "ether, I ^- is added to the solution of 4.75 parts by weight of lithium-aluminum kyaride in 300 parts by volume" of abs. Drip in ether within two hours. Then mr hitst to 24 hours at a bath temperature of 70 ° Then we worked up as usual and distilled the base, bp., "106 <= 10S. The hydrochloride has an mp _t . from

Example 11:

9 ° Amino methyl phenanthrene: _

10 _s 5 parts by weight of 9-phenanthrylcarboxamide were placed in 44 = ® extraction thimble. The solution of 3.5 parts by weight of lithium aluminum hydride in 500 parts by volume of abs was then heated. Aether until the © Hüls® was empty. After working up, dse-9-aminomethyl = phenanthrene which melts at 107 ° is obtained.

Example 12:

p-dimethylaminoethyl benzhydryl ether;

27 parts by weight of DiphenyltnethQxy <= acetic acid © dimethylamide in 100 ¥ olο parts abs. Aether is added to the solution of 4 _? 2 parts by weight of lithium aluminum hydride in 400 parts by volume of absolute ether slowly sutropfea »After the usual work-up, the β ~ Dl = methylaminoethyl benzhydryl ether already described in the literature is obtained as an oil from Kp. _Q ^ 122 »125 °. The hydrochloride melts at 159-160 °, the picrate at

Claims (1)

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