# US 10,370,254 B2 · Method for producing borazane

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,370,254 B2
- Document ID: US10370254B2
- Status: Granted
- Kind: B2
- Application number: 15/313,287
- Filed: 2015-05-22
- Published: 2017-10-26
- Granted: 2019-08-06
- Earliest claimed: 2014-05-23
- Assignees: Airbus Safran Launchers SAS; Centre National De La Recherche Scientifique; Universite Claude Bernard Lyon I
- Applicants: Airbus Safran Launchers SAS; Centre National De La Recherche Scientifique; Universite Claude Bernard Lyon I
- Inventors: Guy M. Jacob; Henri R. Delalu; Ahmad A. El Hajj
- Web page: https://patentgrep.com/patent/US10370254B2

## CPC

- C01B 35/146: {Compounds containing boron and nitrogen, e.g. borazoles (ammonium tetrafluoborates C01B35/063; ammonium borates C01B35/12)}
- C01B 35/14: Compounds containing boron and nitrogen, phosphorus, sulfur, selenium or tellurium
- C07F 5/022: {without C-boron linkages}
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)

## Abstract

A process for obtaining borazane (NH3—BH3) includes introducing anhydrous liquid ammonia (NH3(l)) into a reactor thermostatically regulated to between a temperature θ1 and 40° C.; introducing, with stirring, into the reactor an amine borane complex (Am.BH3), the corresponding amine (Am) of which is soluble in anhydrous liquid ammonia only to a proportion of less than 10 g in 100 g of ammonia at 20° C., being introduced in an amount such that the mole ratio R=(NH3(l))/(Am.BH3) is greater than or equal to 5; stirring the mixture; stopping the stirring to obtain two demixed phases: a light phase constituted essentially of a solution of anhydrous liquid ammonia (NH3(l)) containing borazane; and a heavy phase constituted essentially of the amine corresponding to the amine borane complex introduced; isolating the borazane and drying under vacuum thereof; the temperature θ1 being greater than or equal to the melting point of the amine borane complex.

## Claims

### Claim 1

A process for obtaining borazane (NH3—BH3), comprising:
providing a reactor, equipped with a stirring system and thermostatically regulated at a temperature between a temperature θ1 and 40° C.;
introducing anhydrous liquid ammonia (NH3(l)) into said reactor;
introducing, with stirring, into said reactor containing anhydrous liquid ammonia (NH3(l)), an amine borane complex of formula Am.BH3 to obtain a mixture, amine Am of said complex of formula Am.BH3 being soluble in anhydrous liquid ammonia only to a proportion of less than 10 g in 100 g of anhydrous liquid ammonia at 20° C., said amine borane complex of formula Am.BH3 being introduced in an amount such that the mole ratio R=anhydrous liquid ammonia (NH3(l))/amine borane complex of formula Am.BH3 is greater than or equal to 5;
stirring the mixture to a point of depletion of said amine borane complex of formula Am.BH3;
stopping the stirring and obtaining, in said reactor, two demixed phases:
a light phase constituted essentially of a solution of anhydrous liquid ammonia (NH3(l)) containing borazane; and
a heavy phase constituted essentially of the amine Am corresponding to the amine borane complex of formula Am.BH3 introduced;
isolating said borazane and drying under vacuum thereof;
said temperature θ1 being greater than or equal to the melting point of said amine borane complex of formula Am.BH3.

### Claim 2 (depends on 1)

The process as claimed in claim 1, wherein said anhydrous liquid ammonia (NH3(l)) is introduced at a pressure of between 5×105 and 106 Pa (5 and 10 bar).

### Claim 3 (depends on 1)

The process as claimed in claim 1, wherein said reactor is, prior the introduction of the anhydrous liquid ammonia (NH3(l)), rendered inert.

### Claim 4 (depends on 1)

The process as claimed in claim 1, wherein said amine borane complex of formula Am.BH3 is an alkylamine borane complex, the amine Am of which is a tertiary amine.

### Claim 5 (depends on 4)

The process as claimed in claim 4, wherein said amine borane complex of formula Am.BH3 is chosen from the N,N,N-triisopropylamine borane complex, the N,N-diisopropyl-N-ethylamine borane complex, and mixtures thereof.

### Claim 6 (depends on 1)

The process as claimed in claim 1, wherein 5≤R≤20.

### Claim 7 (depends on 1)

The process as claimed in claim 1, wherein said reactor is thermostatically regulated between 18 and 30° C. and wherein said amine borane complex of formula Am.BH3 consists of the N,N-diisopropyl-N-ethylamine borane complex.

### Claim 8 (depends on 1)

The process as claimed in claim 1, wherein isolating borazane comprises:
discharging said heavy phase, constituted essentially of said amine Am;
removing by evaporation the anhydrous liquid ammonia (NH3(l)) of said light phase remaining in said reactor, thereby obtaining a solid; and
suction filtrating said solid obtained.

### Claim 9 (depends on 1)

The process as claimed in claim 1, wherein said isolation of borazane comprises:
removing, by evaporation, the anhydrous liquid ammonia (NH3(l)) of said light phase, lying on said heavy phase, a second mixture resulting from said removal; and
filtrating said second mixture.

### Claim 10 (depends on 8)

The process as claimed in claim 8, further comprising recompressing ammonia removed by evaporation.

### Claim 11 (depends on 1)

The process as claimed in claim 1, further comprising, upstream, a synthesis of the amine borane complex of formula Am.BH3 from diborane (B2H6) and an amine Am.

### Claim 12 (depends on 8)

The process as claimed in claim 8, further comprising, upstream, a synthesis of the amine borane complex of formula Am.BH3 from diborane (B2H6) and an amine Am and wherein a majority of the amine Am generated in said reactor from said amine borane complex of formula Am.BH3 , at least the amine Am present in said heavy phase, is recycled for performing said synthesis of the amine borane complex of formula Am.BH3.

### Claim 13 (depends on 5)

The process as claimed in claim 5, wherein said amine borane complex of formula Am.BH3 consists of the N,N-diisopropyl-N-ethylamine borane complex.

### Claim 14 (depends on 6)

The process as claimed in claim 6, wherein 8≤R≤20.

### Claim 15 (depends on 6)

The process as claimed in claim 6, wherein 8≤R≤12.

### Claim 16 (depends on 7)

The process as claimed in claim 7, wherein said reactor is thermostatically regulated between 18 and 25° C.

### Claim 17 (depends on 7)

The process as claimed in claim 7, wherein said reactor is thermostatically regulated at 20° C.

### Claim 18 (depends on 9)

The process as claimed in claim 9, further comprising recompressing ammonia removed by evaporation.

### Claim 19 (depends on 10)

The process as claimed in claim 10, further comprising recompressing ammonia removed by evaporation and recycling thereof into said reactor.

### Claim 20 (depends on 18)

The process as claimed in claim 18, further comprising recompressing ammonia removed by evaporation and recycling thereof into said reactor.