DE1048586B - - Google Patents

Description

GERMAN

INTERNAT. KL.

C07f

PATENT OFFICE

V. Z5592IVb / 12q

REGISTRATION DATE: JUNE 8, 1956

NOTICE THE REGISTRATION AND ISSUE OF THE

DISPLAY: JANUARY 15, 19 5 9

The preparation of N-substituted borazanes of the general formula H ₃ B · NR'R "R"', in which R', R "and R '" denote an aliphatic, cycloaliphatic and / or aromatic hydrocarbon radical, has not yet been satisfactorily solved. Only N-trimiethylborazane has been described so far. Various methods are known for its representation. For example, a hydrogen boride, for example the diborane B ₂ H ₆ , is reacted with trimethylamine to form the N-trimefhylborazane (cf. ABBurg, HI Schlesinger: Journal of American Society, 59, pp. 780 to 787 [1937]). One type of representation of N-trimefihylborazane related to these methods consists in the reaction of borine carbonyl H ₃ B · CO with trimethylamine (cf. HI Schlesinger, ABBurg: Chemical Reviews, 31, p. 19 [1942]).

According to the process of US Pat. No. 2,678,949, compared with the processes listed above, the use of free gaseous hydrogen boride in the production of N-substituted borazanes is avoided, but thermal decomposition of tetramethylammonium borohydride (CH ₃ ) ₄ NBH ₄ according to the equation.

(CH _{3) 4} NBH ₄ -> H ₃ BN (CH _{3) 3} + CH ₄

lost a quarter of the already existing hydrogen boride content. In addition, the manufacture the starting compounds necessary for the process are associated with particular difficulties, because for the production of quaternary ammonium borohydrides, first of all a metal borohydride must produce.

It has been found that all hydrocarbon radicals of boron hydrocarbons of the general formula BR ₃ , in which R denotes a hydrocarbon radical, can be replaced directly by hydrogen without special precautionary measures if the boron hydrocarbons are in the presence of tertiary amines of the general formula NR'R "R"', in which R', R "and R '" mean a hydrocarbon radical, in particular an aliphatic, cycloaliphatic and / or aromatic hydrocarbon radical, heated to temperatures above 120 ° C. with hydrogen under pressure.

At temperatures above 140 ° C., a rapid reaction is preferred according to the following general equation the N-trisubstituted borazanes in almost quantitative yield educated:

Method of manufacture
of hydrocarbon residues,
Containing hydrogen and nitrogen
Boron compounds

Applicant:

Study Society Coal mbH,
Mülheim / Ruhr, Kais er-Wilhelm-Platz 2

Dipl.-Chem. Dr. Roland Köster, Mülheim / Ruhr, has been named as the inventor

loose liquids, the odor of which generally reveals neither the presence of amine nor that of hydrogen boride. The only one so far in the N-trisubstituted borazane, N-trimethylborazane, is a well-crystallized, easy, sublimable connection. The reaction products of the invention are thermal extremely stable connections. They are insensitive to air and do not readily react with it alkaline or neutral aqueous solvents. Hydrogen is only released as a gas when acidified.

The N-trialkylborazanes are similar in inorganic and especially organic chemistry

R ₃ B + NR ₃ + 3H, =

H ₃ B

NR ₃ + 3HR.

Almost without exception, the compounds produced by the process according to the invention have the same color the metal borohydrides are suitable for reduction purposes. Compared to alkali and alkaline earth boranates they have the advantage of not reacting as strongly alkaline when the reducing effect is used Has. Nevertheless, their reducing power is hardly changed compared to that of complex metal borohydrides. Compared to these, they have the further advantage that they can be used in many organic solvents are much more soluble.

The borazanes prepared according to the invention can be cleaned in a simple manner and are generally used by recrystallization from hydrocarbons, but preferably by distillation or Sublimation, preserved in a completely pure form. By and large are those made in accordance with the invention However, compounds are immediately so pure that such cleaning processes are not necessary.

809 729i'285

Claims (1)

1 U4Ö OÖD Example 1 N-trimethylborazane (borine trimethylamine) 123 g (0.79 mol) of the mixture of trimethylamine and boron triethyl are in one. 500 cm3 autoclave; filled. After injecting 30 atm of hydrogen, the mixture is heated to 180 to 190 ° C. with shaking and allowed to react at this temperature for 10 hours, the pressure dropping to 120 atm at room temperature. After the resulting ethane (72 g) has been blown off, a colorless, solid compound remains in the autoclave. This can be recrystallized from warm hexane. Gas analysis (decomposition of a substance sample with dilute acid) of the N-trimethyliborazane purified in this way gives the expected amount of hydrogen. Example 2 N-triethylborazane (borine-triethylamine) In a 200 cm3 autoclave, the mixture of 63 g (0.346 mol) of boron triisobutyl and 35.2 g (0.349 mol) of triethylamine is heated to about 180 ° C. with shaking, after 320 atm hydrogen were injected. Within about 5 hours the pressure has dropped to about 95 atm at 180 ° C; after isobutane has been blown off, hydrogen is injected again up to 300 atmospheres and the reaction is brought to an end at the same temperature under the specified conditions. After a further 5 hours, the pressure reaches a constant end value (at 20 ° C approx. 70 atm). A total of 58 g of isobutane is collected in a low-temperature trap. 40 g of a colorless, slightly cloudy liquid are precipitated from the autoclave. After distillation (boiling point 14/15 = 96 to 97 ° C.), N-triethylborazane is obtained in analytically pure form with the corresponding hydrogen value. Example 3 Ni-pimethylcyclohexylborazane (borine-dimethylcyclohexylamine) A mixture of 34 g (0.345 mol) of boron triethyl and 44 g (0.345 mol) of dimethylcyclohexylamine is reacted in a 300 cms autoclave with 300 atm of hydrogen at 190 to 200 ° C for 15 hours brought. The pressure drops to a constant value (80 atm at room temperature). After 32 g of ethane have been blown off together with the excess hydrogen, the autoclave contains a colorless, well-crystallized compound. Even as a crude product, this results in a decomposition with dilute sulfuric acid. Hydrogen hydride content of about 95% of theory. After recrystallization from hexane or cyclohexane, the dimethylcyclohexylborazane can be obtained in completely pure form (nicely formed crystals) with a melting point of 49 ° C. The yield is 95% of theory. Example 4 N-Dimethylphenyl'borazan (Borin ^ dimethyIanilin) The mixture of 38 g (0.388 mol) of boron triethyl and 47 g (0.388 mol) of dimethylaniline is heated to 190 ° C under 500 atm of hydrogen. After a reaction time of about 15 hours, the pressure drop has come to an end. The resulting ethane (34 g) is blown off together with the excess hydrogen. The autoclave then contains 46 g of a yellow-colored liquid. This can be distilled under reduced pressure, although partial decomposition occurs. A colorless liquid is obtained, the hydrogen hydride content of which corresponds to N-dimethylphenylborazari. is equivalent to; the yield is between 70 and 80% of theory. Example 5 B (η- C3 H7) 3 + N (C2 H5) 2 (n - C4 H9) + 3 H2 -> H3B · N (C2H5) 2 (n-C4H9) +3 C3H8 A solution of 140 g (1 Mol) boron tri-n-propyl and 129 g (1 mol) diethyl-n-butylamine in 100 ecm cyclohexane are filled into a 750 cms autoclave under nitrogen. After pressing on 300 atm of hydrogen is shaken at a temperature of about 200 ° C for 5 hours, the pressure drops rapidly. Then, after cooling, the propane formed is blown off with the excess hydrogen. The cyclohexane solution of N-diethyl-n-butylborazane is poured out and, after the solvent has been distilled off, 140 g (quantitative yield) of the liquid borazane are obtained as a colorless residue. The compound can be distilled under reduced pressure. Example 6 B (CeH5) 34-N (n-C4H9) s + 3H2 -> Benzene ■> H3B ■ N (n, -C4H9) 3 + 3 C6He A solution of 121 g (0.5 mol) of boron triphenyl in 250 ecm of benzene. 93 g (0.5 mol) of tri-butylamine are added and 200 atm of hydrogen are injected. It is then heated to about 200 ° C., the pressure dropping to a constant value (about 30 atm at room temperature) within 4 to 5 hours. After cooling and blowing off the excess hydrogen, the benzene solution of the N-tri-n-butylborazane formed can be filled out. One receives after. Distillation of the benzene (at the end under reduced pressure) a colorless liquid which can be distilled in a high vacuum; the yield is almost quantitative. EXAMPLE 7 A mixture of 1.4 kg (10.0 mol) of boron tri-n-propyl and 1.1 kg (about 11.0 mol) of triethylamine is heated to 200 to 220.degree. C. in a 5-1 autoclave equipped with a stirrer. A hydrogen bottle is connected to the autoclave via a reducing valve, so that a hydrogen pressure of about 20 atm is constantly maintained during the reaction. The reaction mixture is allowed to react in this way for about 48 hours, the propane produced from time to time being removed via a pressure cooler. 1.1 kg of N-triethylborazane are obtained (yield about 95 to 96% of theory), which can be purified by a subsequent distillation (boiling point 12 = 100 to 101 ° C.). Patent claims: 1. A process for the preparation of boron compounds containing hydrocarbon radicals, hydrogen and nitrogen !, characterized in that boron compounds of the general formula BR ₃ , in which R is a hydrocarbon radical, in