FR2554810A1 - PROCESS FOR THE PREPARATION OF AMINOBENZYLAMINE - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS FOR PREPARING M- OR P-AMINOBENZYLAMINE. THIS PROCESS CONSISTS OF SUBJECTING THE M- OR P-NITROBENZALDEHYDE AND AMMONIA TO CATALYTIC REDUCTION IN THE PRESENCE OF A REDUCTION CATALYST IN AN ORGANIC SOLVENT; IN REDUCTION, THE YIELD IS IMPROVED BY PREPARING IN ADVANCE A SOLUTION OF NITROBENZALDEHYDE AND AMMONIA IN AN ORGANIC SOLVENT AND THIS SOLUTION IS INTRODUCED IN FRACTIONS INTO THE REACTOR.

Description

The present invention relates to a novel process

  for preparing m- or p-aminobenzylamine, and more particularly

  firstly, an advantageous process, from the industrial point of view,

production of these compounds.

  Aminobenzylamine is an important material

  as a hardening agent for epoxy resins, such as

  first stage for obtaining polyamides and polyimides and as a raw material for obtaining intermediates

  in the production of pesticides and pharmaceuticals

ticks.

  With regard to aminobenzylamine, we knew

  up to now processes for its preparation, which makes

  Nitrobenzaldehyde or nitrobenzonitrile was used as starting material. For example, as a process

  using the first compound as a raw material for

On the other hand, we knew the following:

  (i) A process in which nitrobenzyl bromide derived from

  m-nitrobenzaldehyde is reacted with phthalate

  potassium limide to form N- (m-nitrobenzyl) phthalimide

  which is then reduced in two stages to give maminobenzylamine (yield: about 20%)

  (N. Kornblum et al., J. Am Chem Soc., 71, 2137 (1949)).

  (ii) A process in which m-nitrobenzaldehyde is fed

  to react with the phenylhydrazine to give a compound of

  drazone which is then subjected to a catalytic reduction

  to form m-aminobenzylamine (yield: 60%) (A. Sid-

  diqui et al., Synth. Comm, 7, 71-78 (1977)).

  (iii) From m-nitrobenzaldehyde the m-nitro-

  benzaldoxime, which is then subjected to a

  high pressure lytic with a Raney nickel catalyst to obtain m-aminobenzylamine (yield: 52%)

  (J. R. Griffith et al., NRL Report 6439).

  Further, as a method of using the second compound as starting material, the following were known: (iv) A process in which the p-aminobenzonitrile derivative 25548 10iO

  p-nitrobenzonitrile is reduced with lithium hydride

  thium and aluminum by giving p-aminobenzylamine (

  37%) (N.C. Brown et al., J. Medicinal Chem., 20,

1189 (1977)).

  (v) A process in which m-nitrobenzonitrile is subjected to high pressure catalytic reduction with Raney nickel as a catalyst to obtain m-aminobenzylamine

  (Yield: 49%) (J. R. Griffith et al., NRL Report 6439).

  However, according to the procedures (i) and (ii) above,

  A relatively expensive compound such as phthalate is used.

  potassium hydroxide or phenylhydrazine in an equiva-

  valentine or superior to prepare an intermediary who is

  reduced by giving the desired compound, but these procedures

  dice are uneconomical because the reaction process is long, and the recovery of by-products leads to

  fresh and tedious. In addition, the procedure (iv) also

  disadvantages that the reducing agent is not only

  expensive, but is also difficult to handle and, in addition, in the case of processes (iii) and (v) in which a high-pressure catalytic reduction is carried out in an autoclave with Raney nickel as catalyst, it is

  It is necessary to use an expensive device in order to increase

  be the yield. In particular, the method (iii) has as

  Another disadvantage is that the reaction process is prolon-

  ge, because it is realized through an aldoxime as

  intermediate and, in addition, the hydroxylamine used in the preparation of this aldoxime is also relatively expensive.

  The invention proposes to provide a method for pre-

  parenteration of aminobenzylamine directly from nitro-

  benzaldehyde as the starting material, without going through the

  trobenzaldoxime and with a high yield.

  The present invention resides in a process of pre-

  m- or p-aminobenzylamine, which consists of submitting

  be a nitrobenzaldehyde corresponding to the formula:

25548 10

02N4 CHO

  wherein a nitro group is located at the position m or the position p. and ammonia to a catalytic reduction in the presence of a reduction catalyst in a

organic solvent.

  In the catalytic reduction of the present invention

  the reduction may be carried out in the presence of ammo-

  niac in an amount of one mole or more, preferably

  3 to 10 moles based on one mole of nitrobenzaldehyde.

  If the amount of ammonia is less than 3 moles, the quantity

  byproducts such as a secondary amine

  increase, while even if it exceeds 10 moles,

  this has practically no effect and these quantities

  They are therefore unprofitable. Ammonia in the form of gas can be used, but ammonia is preferably used.

  liquid, in the present invention.

  As an organic solvent, any soil can be used.

  usually used for catalytic hydrogenation

  that, but it is more advantageous to use alcohol

  anhydrous bottoms in which the ammonia is very soluble, for example methanol, ethanol, etc .; the amount of solvent

  used has no particular limitations, but a

  serving of 1 to 15 times the weight of the amount of material

  first is usually sufficient.

  Examples of the reduction catalyst used in the present invention are those consisting of noble metals such as platinum, palladium, rhodium, etc., and Raney catalysts. When using noble metal catalysts, they can be used even in the form of metal, but in general, catalysts of the type in which the noble metals are supported on the surface of a support such as carbon, silica gel,

  alumina, etc. In particular, the nickel of Ra-

  ney, Raney cobalt, etc., are advantageous from the point of view of

  industrial view. The amount of catalyst used is

  kills between 0.01 and 30% by weight of metal relative to the

  raw material is nitrobenzaldehyde. We prefer

  typically a range of 2 to 20% by weight in the case of Raney catalysts, while a range of 0.1 is used.

  at 5% by weight in the case of noble metals on support.

  In addition, the reaction temperature is preferably

  between 30 and 150 C, in particular between

  and 120 C.

  As the reaction pressure, higher pressures are preferred, but generally a pressure of

  1.0 to 15.0 MPa is suitable. If the reaction pressure is low

  to the point that the reaction does not progress rapidly, the

yield tends to decrease.

  In a general embodiment of the process of the present invention, a catalyst can be added to the raw material dissolved or suspended in

  a solvent, and ammonia and then hydro-

  gene to carry out the reaction until the absorption

  of the latter ceases, but in a preferred form of

  sation, raw material and ammonia (liquid ammonia)

  are dissolved in a solvent, and introducing the solu-

  resulting mixed reaction in a reactor containing

  in advance of hydrogen, a solvent and a bed of

  catalyst, the catalytic reduction is carried out under pressure

  and at the desired temperature. At this moment, the fraction

  The troduct varies somewhat depending on the reaction conditions, but in general the amount is preferably adjusted so that the hydrogen uptake ceases in about 30 minutes.

minutes each time.

  In the above method of introducing the

  fractional dilution, if the reaction pressure is

  too low, it is necessary to reduce the fraction

  pick; this is uneconomical because the reaction time

is extended accordingly.

  In the process of the present invention, when the mixed solution is introduced in fractions,

  a product in a yield higher than that obtained during

  that it is introduced in one go and also the degradation of the catalyst is weak; this process is therefore very advantageous even if the catalyst is reused. In addition, the amount of heat generated during the reaction

  is easily mastered. At the end of the reaction, the cata-

  The lysate is separated by filtration and the filtrate is distilled

  in a conventional manner to obtain the desired product.

  The present invention will be described in more detail with reference to the Examples

Example 1

  In a stainless steel autoclave of 1 liter of

  capacity, 100 ml of methanol and 4.6 g

  nickel nickel) from Raney (manufactured by Toyo CCI),

  then purge with nitrogen, then with hydrogen to re-

  drop the hydrogen pressure to 4.0 MPa and

the temperature at 90 OC.

  60.4 g (0.4 mol) of p-nitrobenzaldehyde, 400 ml of methanol are introduced into a container of raw material.

  and about 80 g of liquid ammonia, and the mixture is then stirred

  be 0 and 5 C for about 30 minutes to obtain a

  mixed solution. This solution is divided into 8 fractions (each

  about 58 g / time) and introduces them into the autocla-

  while maintaining the reaction temperature at 90 C. The hydrogenation reaction of each fraction of about 58 g at a time requires 5 to 15 minutes each, and the total reaction time required is 80 minutes, while

  which 33 liters (normal conditions) in total of hydro-

  gene are absorbed. After aging for about minutes, the reaction solution is allowed to cool to room temperature, then the mass is removed.

  reaction, the filter, and the filtrate is subjected to

  partial vacuum distillation under a pressure of 666-800 Pa to obtain a fraction (distillation temperature: 129.5-130 ° C., (47.8%, 97.7% yield).

  this fraction has a purity of 99.9% according to the

  gas-phase matography and that this is indeed the

  p-aminobenzylamine. Moreover, the values of the

  Basic Analysis (C7HloN2) C H N Calculated (%) 68.8 8.25 22.9 Found (%) 68.8 8.29 22.8

Example 2

  The reaction is conducted in the same way as in

  Example 1 except that the p-nitrobenz

  zaldehyde by m-nitrobenzaldehyde. The reaction is completed in 115 minutes during which 32 liters (normal conditions) of hydrogen are absorbed. The post-treatment is then carried out as in Example 1 to obtain 46.7 g (95.5% yield) of m-aminobenzylamine with a purity of

  99.91%. (Boiling point 131-132 ° C / 800 Pa).

Example 3

  In a stainless steel autoclave with a capacity

  500 ml, 30.2 g (0.2 mol) of P-nitrobenzaldehyde are added.

  dehydrogen, 200 ml of methanol and 4.6 g (in terms of nickel) of Raney nickel (manufactured by Toyo CCI), then purged with

  nitrogen gas, shake for a moment, introduce

  g of ammonia while cooling the autoclave with ice water, then introducing hydrogen under pressure to obtain a pressure of 4.0 MPa, then the temperature is raised to 70 C and the reaction is carried out. this

  temperature for 60 minutes. Thus, 16.3 liters (conditions

  Normal hydrogen contents are absorbed and the reaction is complete. The reaction solution is allowed to cool

  to room temperature, the reaction mass is

  the filter, and the filtrate is distilled

  under partial vacuum under 800 Pa pressure to obtain

  a fraction of 22.0 g (90.0% yield) (temperature

  distillate: 129.5 C-130 C), corresponding to paminobenzylamine. Its purity, according to the chromatography

gas phase is 99.91%.

Example 4

  The reaction is carried out as in Example 3 except that p-nitrobenzaldehyde is replaced by

  m-nitrobenzaldehyde. The reaction ends in 55 minutes

  15,8 liters (normal conditions) of hydro-

  gene are absorbed. Then we conduct the post-treatment com-

  me in Example 3 to get 21.5 9 (88.0% yield)

  m-aminobenzylamine with a purity of 99.94% (b.p.

132 C / 800 Pa).

R EV E N D I C A T I ONS

  1 - Process for the preparation of m- or p-aminobenzyl

  amine, characterized in that it consists in submitting

  trobenzaldehyde corresponding to the formula CHO NO2 in which the nitro group is located at the position m or p. and ammonia to a catalytic reduction in the presence

  a reduction catalyst in an organic solvent.

  2 - Process according to claim 1, characterized

  in that in this catalytic reduction, nitrobenzal-

  dehyde and ammonia first form a mixed solution

  which is then introduced in fractions.

  3 - Process according to claim 1, characterized in that ammonia is used in an amount representing

  3 to 10 times the number of moles of nitrobenzaldehyde.

  4 - Process according to claim 1, characterized in that said organic solvent is a lower aliphatic alcohol. - Process according to claim 1, characterized in that said reduction catalyst is nickel of

Raney or Raney cobalt.

  6 - Process according to claim 1, characterized

  in that said ammonia is used in the form of ammonia

liquid niac.

  7 - Process according to claim 1, characterized in that said catalytic reduction is conducted at a

  temperature between 60 and 120 C.