DE1151511B - Process for the production of dimethylhydroxylamine - Google Patents

Description

ANNOUNCEMENT OF THE APPLICATION AND ISSUE OF THE EXPLAINING PAPER: JULY 18, 1963

Applicant:

Pennsalt Chemicals Corporation, Philadelphia, Pa. (V. St. A.)

Representative: Dr.-Ing. E. Berkenfeld, patent attorney, Cologne-Lindenthal, Universitätsstr. 31

Claimed priority: V. St. v. America, March 30, 1961 (No. 99 354)

Herbert Q. Smith, Trenton, N.J. (V. St. Α.) Has been named as the inventor

Method of manufacture

Dimethylhydroxylamine is known as Rea- ^. ., "_,

tion breaker in the polymerization of olefins ^yon Dimethylhydroxylamm

for the production of synthetic rubber

turns. It can be made in several ways
be e.g. B. by using ethyl nitrate on a 5
Allow methyl magnesium halide to act (J. Am.
Chem. Soc, Vol. 79 [1957], p. 796), or by pyrolysis of amine oxides, such as Ν, Ν-dimethylcyclohexylmethylamine oxide (Org. Synth., Vol. 39 [1957], p. 40).
These procedures are evident to a large- io
technical application not usable.

As early as 1899, D caused us to tan and
Goulding, dimethylhydroxylamine by oxidation
of dimethylamine with hydrogen peroxide (J. Chem. Soc, Vol. 75 [1899], p. 1009). Ob- 15
probably the peroxide reacted after 24 hours
only about 50% of the amine was attacked, and the products of the process consisted essentially of nitrous acid, formic acid and formaldehyde.
Dimethylhydroxylamine could not be detected 20
the. Surprisingly, these researchers found
that the oxidation of diethylamine with hydrogen 2

peroxide led to diethylhydroxylamine. This conversion can also be carried out with the higher homologues as well as the low molecular weight ketones, such as acetone, carry out. It follows that the peroxide 25 diethyl ketone or methyl ethyl ketone. The catalyst Oxidation of dimethylamine of its homologues need not be completely dissolved; it is enough if is not analog. it is only present as a dispersion, albeit in

It has now been found that dimethyl- usually a certain solution is achieved, hydroxylamine by oxidation of dimethylamine The process of the invention can accordingly be used in

obtained with hydrogen peroxide if the Oxy-30 are carried out in an aqueous medium, what dation in the presence of oxides, oxygen acids advantageous over the known process for or alkali salts of the oxo acids of selenium, production of organic hydroxy compounds Molybdenum, tungsten, vanadium, and uranium, with which one primary or secondary amines leads. the aliphatic, cycloaliphatic, araliphatic

It is known to produce organic 35 and heterocyclic series with hydrogen peroxide Hydroxylamine compounds primary amines with oxidized in the presence of formic acid esters. Hydrogen peroxide in the presence of water-soluble The process according to the invention is generally

Salts of molybdenum, tungstic or uranium acid, common with aqueous hydrogen peroxide, and in the presence of a heavy metal ion in the grain, usually with a concentration plexer form binding stabilizer to oxidize. 40 of about 30 percent by weight hydrogen peroxide In view of the fact that the peroxide is available. However, other concentrations can also be oxidized of dimethylamine or its homologues not tration of hydrogen peroxide either in water is analogous, it could not be expected that riger or alcoholic solution would be used, The salts of molybdenum, tungsten or uranium can also be acidified with anhydrous hydrogen peroxide can be used as catalysts for the oxidation of dimethyl 45, if this is not considered to be too dangerous set amines. looks at. Preferably, however, aqueous or

To carry out the alcoholic solutions of hydrogen peroxide process according to the invention if you work in an inert solvent, which uses about 5 to 75 percent by weight of peroxide which dissolves both dimethylamine and the peroxide. contain. The amount of peroxide used should be in Suitable are water, anhydrous or aqueous 50 essentially stoichiometric. If less Methanol, ethanol and other lower aliphatic is used, some unreacted amine remains Alcohols, such as isopropanol or the butanols, and back. On the other hand, there are also large surpluses

3 4

of peroxide useful, but they are added dropwise to the process over 15 minutes. To not at. In general, a small excess of completion of the addition can be 99.9% peroxide of about 10% over the stoichiometric amount consumed, which results from the iodimetric titration applied to yield a full conversion of an aliquot sample. For a gas chromatograph guarantee. 5 graph of the reaction solution was a column of

The process according to the invention is carried out under over 35% Ν, Ν, Ν ', Ν' - tetra - (hydroxyethyl) - ethylene conditions and working methods through diamine on crushed, with a small amount. Generally temperatures are used of sodium carbonate molten diatomaceous earth at about -20 to 20 ⁰ C or lower, 100 ⁰ C and 1.05 kg / cm ² helium carrier gas used and since temperatures of more than about 25 to 3O ⁰ C io found that 23 % of the dimethylamine in D give lower conversions. Albeit the way methylhydroxylamine were converted. The way in which the reactants are added, not withdrawn from the chromatograph, is decisive, as the water and infrared spectrum should preferably be determined. The spectrum of peroxide to a stirred mixture of amine confirmed that the product was dimethyl solvent and catalyst being added. 15 is hydroxylamine.

The reaction can be followed by repeating the above

the amount of unreacted hydrogen per example, but without the use of sodium oxide in a tungstate catalyst removed from the reaction mixture, 98.9% of the peroxide was aliquot sample determined. after the clogging is finished, but it is consumed

No trace of dimethylhydroxylamine was found in the dimethyl-20 obtained as a process product hydroxylamine can optionally be isolated as a salt.

The easiest way to do this is through Example 2

Evaporation of the aqueous solution of a dimethyl

hydroxylamine salt, e.g. B. des Hydrochlorides, SuI- Example 1 was repeated at room temperature

fates or picrates. In general, 25 fetches are unnecessary. When using sodium molybdate as however, the isolation of the process product, since it was a catalyst, was a somewhat smaller conversion reached immediately as an aqueous solution after filtering off the dimethylamine to dimethylhydroxylamine, of the solid catalyst can be used. If you replace the one mentioned in example 1

The catalysts used are oxides, oxygen acids, sodium tungstate, selenium dioxide, sodium vanadate, and alkali salts of the oxy acids of selenium, uranium acid (H ₂ UO ₄ ) or selenic acid (H ₂ SeO ₄ ), molybdenum, tungsten, vanadium and uranium and, if you use it, equivalent results are obtained calculate SeO ₂ , MoO ₃ , WO ₂ , WO ₃ , V ₂ O _3,.

V ₂ O ₅ , U ₃ O ₈ , UO ₃ , selenic acid, selenous acid, molyb- ^Wlrkun § of ^the catalyst on diethylamine oxydic acid, sodium molybdate, tungstic acid, sodium dation

tungstate, potassium tungstate, vanadic acid, Na- 35 A. Usual oxidation in the absence of sodium orthovanadate (Na ₃ VO ₄ ), sodium metavanadate lysators

(NaVO ₃ ), potassium _{pyrovanadate (K 4} V ₂ O ₇ ), sodium- It made a stirred solution of 73.1 g

selenate, lithium molybdate, sodium uranate and H ₂ UO ₄ (1.0 mol) diethylamine in 50 ml of water 161 g are suitable. From this group, the tungstates, (1.45 mol) 30.7% strength hydrogen peroxide during, in particular, sodium tungstate, the most preferred 40 added for 6 hours and occasionally cooled, are catalysts. When using free acids to keep the temperature at 25-30 ° C. Nadi they form the amine salt when they are put into the reaction - leaving 6.2% of the water vessel overnight; the amount of applied stoffperoxides not implemented. For the solution, the catalyst is so small that the amount of 75 ml of a 50% sodium hydroxide solution is added to the amine 45 available for the reaction and the resulting upper layer with other layers is not significantly affected. In 25 ml of a 50% solution of sodium hydroxide, in terms of cost and availability, and then over 5 g of flaky sodium, the alkali salts are generally used, hydroxide-dried. Another formed and these acid salt catalysts are usually small amounts of the upper layer when the ver is used in the form of hydrates. The amount of mixed aqueous layers with a further 50 ml of a turning catalyst can vary considerably. 50% sodium hydroxide solution; The catalyst is effective at amounts such as The organic phase was replaced by the sodium

about 0.5 percent by weight, based on the monohydrate phase, filtered off and distilled, with 25.5 g of tertiary amine set. However, quantities (28.6% conversion, 31% yield) of diethyl such as 10% by weight, based on the amine, can also be used with hydroxylamine as a pale yellowish liquid; Amounts from about 1 to ten. . Kp ₂₄ _ _a5: 53, 57 ° to 58 ° C; η%: 1.4179; 5%> based on the amine, however, will be a preferred specific weight of 0.865. used wisely. _, _ΛΤ . _T,. ,.

In the following examples, the ^B according to the invention is the use of a catalyst

Procedure explained in more detail. 60 The above experiment was repeated with

^. . the deviation that, based on the amine,

JseispieJ l j weight percent sodium tungstate dihydrate during

A 25 percent strength by weight aqueous solution that was present when the peroxide was added, what

Containing 0.104MoI dimethylamine was heated to -5 ° C for 1 hour because of the increased activity in this case cooled and sodium tungstate dihydrate in a 65 claimed. During the workup, however Amount added that corresponds to 3 percent by weight of the amine only a conversion of only 16.6% in ΓΜ-corresponds. Then 0.104 mol hydrogen ethyl hydroxylamine were obtained. This results in a peroxide as a 30% aqueous solution with stirring that the use of a catalyst the

Adversely affected peroxide oxidation of diethylamine to diethylhydroxylamine.

Claims (3)

Patent claims: 1. A process for the preparation of dimethylhydroxylamine by oxidation of dimethylamine with hydrogen peroxide in an inert solvent, characterized in that the oxidation is carried out at a temperature of about -20 to + 2O ⁰ C in the presence of an oxide, an oxygen acid or an alkali salt of an oxygen acid Selenium, molybdenum, tungsten, vanadium or uranium is used as a catalyst. 2. The method according to claim 1, characterized in that that one uses an alkali tungstate, an alkali molybdate or an alkali vanadate as a catalyst used. 3. The method according to claim 1, characterized in that the catalyst used is selenium dioxide used. Considered publications:
German patent specifications No. 951 933, 1 004 191.