US2192523A - Ammonolysis of secondary and tertiary amines - Google Patents

Description

March 5, 1940.

J. F. oLlN ETYAL AMMONOLYSIS OF SECONDARY AND TERTIARY AMINES Filed March 8. 1937 INVENTORS JOHN T, OLm' THOMAS E DEQEQ.

a.. cttw-44 ATTORNEY.

Patented Mar. 5, 1940 STATES' PTENT oFFioE AIWMONOLYSIS OF SECONDARY AND TERTIARY AMINES .lohn F. Olin and Thomas E. Deger, Grosse Ile,

Mich., assignors to The Sharples' Solvents Corporation, Philadelphia, Pa., a corporation of Delaware Application March 8, 1937, Serial No. 129,543

6 Claims.

The present invention pertains to the ammonolysis of derivatives of ammonia containing substituted or unsubstituted aliphatic or hydro-,aro-

R representing the aliphatic or hydro-aromatic radical, X halogen, N nitrogen and I-I hydrogen.

It will be noted that three separate amino cornpounds are produced in accordance with the above reaction, the primary, secondary and tertiary aliphatic or hydro-aromatic derivatives of the ammoniurn halide, depending upon whether the reaction occurs in accordance with Equations 1, 2 or 3. When these three compounds are split by means of a base such as caustic soda, the following reactions occur:

It will be seen from the above equations that when a halogen derivative such as `that discussed above is subjected to ammonolysis to produce simultaneously the primary, secondary and tertiary ammonium chloride derivatives of Equations l, 2 and 3 and these ammonium chloride derivatives are split by means of a base such as caustic soda, a mixture of primary, secondary and tertiary amines is produced. The reactions represented by Equations (2) and (3) above, occur particularly in connection with the ammonolysis of. primary normal halides. The mono-alkyl amines formed by substitution of an amino radical for the halogen radicals of such compounds are in particular commercial demand. The object of the present invention has been to develop a process by which, after separation of the primary amines from a mixture of amines obtained by the performance of Reactions 4, 5 and 6, the separated secondary and tertiary amines may be economically converted into primary amines or the (Cl. ZBO-583) tertiary amines may be converted into secondary amines.

It is known that secondary and tertiary amines of the type indicated on the right hand side of Equations 4, 5 and 6 may be converted into primary amines in accordance withv the following equations:

It is also known that tertiary amines may be converted into corresponding secondary amines in accordance with the following equation:

The object of the present invention has been to eiect reactions indicated in Equations 7, 8 and 9 in an efcient and economical manner on a large A.

scale thereby producing primary amines by-ammonolysis of secondary and tertiary amines,

l and/ or secondary amines by ammonolysis of tertiary amines.

The invention was developed in connection with research designed to convert secondary and tertiary amines containing aliphatic or hydro-aromatic hydrocarbon radicals having between 4 and 8 carbon atoms into primary and/ or secondary amines. l l

The major part of the research upon which the invention was based was performed in connection with attempts to convert diand tri-amyl amines into mono-amyl amines and/or di-amyl amines in y accordance with Equations 78 and 9. In connection with the treatment of secondary and tertiary amines in general to eect these results, the principal feature vof the invention consists in the discovery of a catalyst adapted to effect the above reactions in such a manner as to aiord good yields of resultants at a high rate of conversion of reactants. rIn connection with the treatment of secondary and tertiary amines having hydrocarbon radicals of between 4 `and 6 carbon atoms, the invention includes the discovery of improved catalystsand reaction conditions for eecting the desired conversion with a minimum of degradation of the amino compounds treated into undesired products such as hydrocarbons, hydrogen, carbonand nitriles.

The invention will be best understood by ref- Since the invention was conceived in connection with experiments involving conversion of diandv tri-amyl amines into mono amyl amines, it will be described specically with respect to such operations.

Referring to the drawing by reference characters, dior tri-amyl amine or a mixture thereof is fed from a container I0 continuously into conluence with a stream of ammonia passed from container II. The mixture of poly-amyl amines and ammonia is passed to a heater I3 in which it is heated to a temperature between 225 and 300 C., depending upon the pressure, space velocity, and the type of catalyst to be used in the ensuing ammonolysis reaction. The heated mixture is passed from the heater i3 to a reactor Ill filled with a catalytic mass.

The material of the catalytic mass constitutes the most important feature of the invention. The catalyst consists of activated carbon particles of 4 to 12 mesh size. While these carbon particles have suificientlcatalytic effect to cause the desired reaction to take place in the reactor Id at a fairly high velocity, they are preferably subjected to a special treatment designed to render them more eiective. To this end, the carbon is stirred with a solution of the acetate or nitrate of the metal of which the oxide is ultimately to impregnate the carbon. The salt solution should be of approximately 20% concentration and should contain between 0.25 and 0.75 gram of salt in solution for every gram of carbon which is impregnated. After the carbon has been immersed in the salt solution for a period between 12 and 15 hours, the remaining salt solution is drained from the carbon and the wet carbon is heated to a temperature between 350 and 400 C. for a period of 2 to 3 hours in order to convert the salt into the corresponding oxide. The catalyst prepared in this manner is then placed in the reactor I as stated above.

The reactor is maintained at a temperature of 240 to 325 C. depending upon the nature of the amine being subjected to ammonolysis, the nature ofthe catalyst and the space velocity. In this connection it is to be noted that butyl amines should be subjected to temperatures in the heaters I3 and lll which are approximately 25 higher than those employed in the corresponding treatment of amyl amines, for a given space velocity and pressure. I-Iexyl and cyclohexyl amines should be subjected to temperatures approximately 25 degrees lower than those employed in converting amyl amines under similar conditions. Material passed through the reactor llt is condensed in condenser I 5 and passed thence to a container I6.

The best impregnating material for suppleinenting the catalytic eifect of the activated carbon used as a catalyst in the practice of the process is manganese oxide and the preparation of this catalyst involves impregnating the carbon with manganese nitrate as described above. The oxides of aluminum, cerium, thorium, silicon, chromium, zinc or iron may be used in place of the manganese oxide as a promoting material for the carbon but these oxides have not been found to be as desirable as manganese oxide, in that they produce greater quantities of by-products on the one hand or are less active on the other.

The pressure under which the ammonia and amines are passed confluently through the series of steps discussed above may be varied within Wide limits within the practice of the invention. It is only necessary that sufficient pressure be employed to cause the desired ow of these reactants through the apparatus and the pressure may therefore vary between 10 mm. absolute and 1000 pounds per square inch gauge pressure. Excellent results have been obtained in connection with pressures of about 300 pounds per square inch.

Care should be taken to avoid temperatures which are substantially higher than those discussed above in connection with the operation of the reactor I4, for much higher temperatures will result in a substantial amount of undesired pyrolysis of the materials under treatment in cases in which secondary and tertiary amines containing hydrocarbon radicals having between 4 andG carbon atoms are treated. The lower limits of the temperatures necessary to effect fairly rapid conversion of the amines are substantially the lower limits indicated with respect to the reactor I4 and the upper limits are substantially the limits necessary to avoid undesired pyrolysis but these limits will vary somewhat depending upon the particular metal oxide with which the carbon is impregnated, pressure and other factors. As a general rule, it may be stated that the oxides which have the maximum benecial effect in promoting the desired reaction also have a maximum eifect in promoting pyrolysis.

The velocity of iiow of materials through the process may vary within fairly wide limits, as may also the ratio of ammonia to secondary and/ or tertiary amines. In the treatment 0f diamyl amine to produce mono-amylamine, ex cellent results have been obtained by passing a molecular excess of ammonia through the applaratus bearing a ratio of between 5 and 15:1 to

the di-amyl amine under treatment. Best results have been attained when these materials are passed through the apparatus at a velocity of between 200 and 2000 liters of gaseous mixture per hour per liter of catalyst, the volume of gaseous mixture being computed on the assumption that the mixture is under standard conditions of zero degrees C. and 760 mm. pressure (space velocity of ZOO-2000).

Optimum results have been attained in conversion of poly-amyl and -butyl amines into corresponding mono-amines when temperatures or 24U-325 C. are used in connection with a space velocity of 500-1000. lf the space velocity is substantially lowered the operating temperature may be lowered; and if the space velocity is increased, a more elevated temperature will be necessary. To show the magnitude of such effect, it is estimated that at a space velocity of 10 one might use a temperature as low as 180 C. with good results; while at a space velocity of 35,000 a temperature of 400 C. might be necessary for good conversion.

Pressure will also play an important part in. reaction velocity, since the greater the pressure, the greater will be the concentration of reactants in contact with the catalyst. Thus at 150 pounds per square inch, ten times as lmuch gas will be in contact with the catalyst as at atmospheric pressure. Thus, increase in pressure, like decrease in space velocity, makes possible the use of lower temperatures.

= EXAMPLE I M onoamylamine from diamylamine Diamylamine in container Ill and ammonia in container Il were pumped in a mol ratio of 8.7 ammonia 1 diamylamine and mixed before entering preheater I3, where the liquid mixture was completely volatilized and entered the bot- 76 tom of 'reactor I4 containing liters 'of a catalyst, in this case activated carbon impregnated with manganese oxide. The temperature of the 'reactor was 237 C. and pressure was 300 lbs/sq. in. The space velocity of the gases passing through the reactor wasf601 liters gas per liter of catalyst per hour. At `the end of 3.32 hours 25.4 lbs.` ci' diamylamineand 23.9 lbs. of

ammonia had been passed through the reactor.

The gases leaving the top of reactor I4Y were condensed in condenser I5'andcollected in receiver I8. The ammonia was distilled oi from the recovered liquid Aunder approximately 250 lbs. pressure and the residue cooled to room tem- The conversion to monoamylamine in this run was 35.9% and the yield of monoamylamine 74.5%.

EXAMPLE II The same method was used as in Example I.

The diamylamine and ammonia were pumped into the preheater at a mol ratio of 11.31 ammonia 1 diamylamine. 6.9 liters of catalyst, which in this case was activated carbon impregnated with cobalt oxide was retained in the reactor. The temperature was 236 C. and pressure was 300 lbs. At the end of 3.55 hours, 23.8 lbs. diamylamine and 29.19 lbs. ammonia had been pumped through at a space velocity ofV 774 liters gas per liter catalyst, per hour. After the ammonia was distilled ol from the liquid, the residue was fractionated and the following cuts were made.

To 95 C. 154 g. 92.3% monoamylamine 95-105 2761 g. 98.3% monoamylamine 105-124 87 g. 68.0% monoamylamine 124-220 2921 g. 85.2% diamylamine Residue 2113 g. 98.0% triamylamine The conversion to monoamylamine in this run was- 37.0% and yield of monoamylamine was EXAMPLE III A 934:1 mol ratio of ammonia to diamylamine was preheated and passed-through a reactor at atmospheric pressure and 325 C. The reactor contained 2.0 liters activated carbon impregnated with manganese oxide. The gases Were passed through at a space velocity of 1080 liters gas per liter catalystper hour. The ammonia was removed from the recovered liquid and the residue fractionated. The usual cuts were made and a 33.6%` conversion and yield of monoamylamine was obtained.

EXAMPLE IV Monobutylamz'ne from dbutylamine The dibutylamine and ammonia at a m01 ratio of 10.05 ammoniarl dibutylamine were pumped through the preheater and the reactor at a temperature of 293 C. and pressure of 300 lbs/sq. in. The reactor contained 7.0 liters of activated carbon impregnated with manganese ox-l ide. "Ifhespace velocity wasgliters gas per liter catalyst per hour.l At the end of 3.7 hours,

25.7 lbs. dibutylamine and 34.0 1bs.ammonia were added.v 'I'he ammonia was distilled from the recovered liquid and the residue was. fractionated into the followingcuts:

To 82 C., 3728 g. 95.2% monobutylamine 82-120 517 g. 54.2% monobutylamine -140 27g 66.8% dibutylamine V-170 4911 g'. 99.0% dibutylamine 1770-200 63 g. 82.5% dibutylamine 20G-225 1485 g 97.4% tlbutyiamne Residue 878 g y .The conversionto monobutylamine was 31.4% L

and the yield ofmonobutylaminel was 77.6%.-

EXAMPLE `V M onobatylamine from tributi/lamme The tributylamine and ammonia ata mol ratio of 13.56 ammoniazl tributylamine were pumped through a preheater and reactor held at 53759 C. :and 300 lbs. per sq. impressure.

The reactor contained 8.0 liters activated carbon impregnated with manganese oxide. The gases were passed through the reactor at a space velocity of 644 liters gas per liter of catalyst per hour. At the end of 3.92 hours 25.22 lbs. tributylamine and 31.42 lbs. ammonia had passed through the apparatus. The ammonia was removed bypressure distillation from the recovered liquid. 'Ihe residue-was fractionated into the following cuts:

To 70 C 25 g. 90.6% monobutylamine 70- 79 3883 g. 1 91.4% monobutylamine 79- 82 669 g. 87.9% monobutylamine 82-118 855 g. 21.8% monobutylamine 118-140 186 g. 43.5% dibutylamine 140-170 2388 g. 96.2% dibutylamine -195 86 g. 70.3% dibutylamine -220 626 g. 97.0% tributylamine Residue 2267 g. v

The conversion to monobutylamine was 32.0%. The yield of monobutylamine'was 43.0%.

Modifications will be obvious to those skilled in the art andwe do not therefore wish to be limited except by the scope of the subjoined claims. l y

We claim: I

1. The process of converting amines chosen from the group consisting of secondary and tertiary alkyl amines containing between 1 and 8 carbon atoms in their alkyl radicals, and secondary and tertiary cyclohexyl amines, into thev corresponding primary and secondary amines, which comprises reacting said secondary and tertiary amines with ammonia by passing said amines together with ammonia over la catalyst consisting of activated carbon impregnated with manganese oxide.

2. The process of converting amines chosen from the group consistingl of secondary and tertiary -alkyl amines containing between A1 and 8 carbon atoms in their alkyl radicals, and'vsecondary and tertiary cyclohexyl amines, into the corresponding primary and secondary amines,

which comprises reacting said secondary and tiary alkyl amines containing between 1 and 8 75 carbon atoms in their alkyl radicals, and secondary and tertiary cyclohexyl amines, into the corresponding primary and secondary amines which comprises reacting said secondary and tertiary amines with ammonia by passing said amines together with ammonia at a temperature between 240 C. and 400 C. over a catalyst consisting of activated carbon impregnated with manganese oxide.

4. The process of converting amines chosen from the group consisting of secondary and tertiary alkyl amines containing between l and 8 carbon atoms in their alkyl radicals, and secondary and tertiarycyclohexyl amines, into the corresponding primary and secondary amines which comprises reacting said secondary and tertiary amines- With ammonia by passing said amines together with ammonia at a temperature between 240 and 325 C. over a catalyst consisting of activated carbon impregnated with manganese oxide.

5. The process of converting amines chosen from the group consisting of secondary and tertiary alkyl amines containing between 4 and 6 carbon atoms in their alkyl radicals, and secondary and tertiary cyclohexyl amines, into the corresponding primary and secondary amines, which comprises reacting said secondary and tertiary amines with ammonia by passing said amines together with ammonia over a catalyst consisting of activated carbon impregnated with manganese oxide.

6. The process of converting amines chosen from the groupv consisting of secondary and tertiary alkyl amines containing between 4 and 8 carbon atoms in'their alkyl radicals, and secondary and tertiary cyclohexyl amines, into the corresponding primary and vsecondary amines, Which comprises reacting said secondary and tertiary amines with ammonia at a temperature between 240 and 325 C. over a catalyst consisting of activated carbon impregnated with manganese oxide.

JOHN F. OLIN. THOMAS E. DEGER.

CERTIFICATE OE CORRECTION.' Patent No. 2,192,525. A March 5, 19u05.

' JOHN E. OLIN, ET AL.

It is hereby certified that error appears in the printed specification` of the above numbered patent requiring correction as follows: Page 5, sec-v ond column` line 25, Example V, for "5750 C." .read --2750 C.; and that. thepsaid Letters Patent Should be read with this Corection therein that the same may conform to the record of the case in the Patent Office.

signed and Sealed this Tth day of. Nay, A.` D., 19m.

l Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

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