Borazine Chemistry - Advances in Chemistry (ACS Publications)

Borazine Chemistry

1

2

L. F.HOHNSTEDT and G. W. SCHAEFFER

Downloaded by NORTH CAROLINA STATE UNIV on November 20, 2012 | http://pubs.acs.org Publication Date: June 1, 1961 | doi: 10.1021/ba-1961-0032.ch026

Department of Chemistry, St. Louis University, St. Louis, Mo.

Interest in borazine, B H N H , arises in part from its similarity to benzene in structure and physical prop erties. Relatively little is known of its chemistry, prin cipally because of difficulties involved in the original synthetic procedures for borazine and its derivatives. The borazine ring undergoes some substitution reac tions. However, unlike benzene, borazine and certain of its derivatives undergo addition reactions readily to give products like B H N H .3HX, where X = CI, Br, or OH. Also borazine undergoes extensive decom position in the liquid phase, even at room tem perature. Improved syntheses recently have been developed for borazine and various types of substi tuted borazines. It is anticipated that these improve ments will lead to a greatly expanded knowledge of borazine chemistry. 3

3

3

3

3

3

3

3

Borazine, B N H , was isolated and characterized i n 1926, at which time i t was sug gested that i t had a cyclic, benzenelike structure, with Β and Ν atoms alternating i n the ring (84). B o t h chemical and physical properties of borazine support such a structure and electron diffraction data are consistent with a planar molecule i n which the Β—Ν bond distance is 1.44 ± 0.02 A . and the ring angle is 120° (86). 3

3

e

H H B - % H

I H

V

I N

8

H

Borazine Β—Ν = 1.44 A . Ν—Η = 1.02 A . Β — Η = 1.20 Α. M o l . wt. = 80.5

Benzene C — C = 1.42 A . C—Η = 1.08 A . M o l . wt. = 78.1

It is assumed that the extra electron pair on each nitrogen atom takes part i n ring bonding, so that borazine is isoelectronic with benzene. The molecule therefore should be considered i n terms of resonance, taking into account single-bonded and doublebonded structures. This view is supported b y a variety of spectral studies as well as the fact that the Β—Ν distance of 1.44 A . is intermediate between that expected for a single bond (1.54 A . ) and that for a double bond (1.36 Α . ) . Though similar i n structure and molecular weight, borazine differs from benzene i n that i t is heteroatomic, which results in charge distribution different from that i n benzene, represented b y a formal positive charge on nitrogen atoms and a formal negative charge on boron atoms. O n the basis of spectra of substituted borazine and comparison with carbon compounds, some Present address, Department of Chemistry, Polytechnic Institute of Brooklyn, Brook lyn, N . Y . Deceased August 17,1959. 232 1

2

In BORAX TO BORANES; Advances in Chemistry; American Chemical Society: Washington, DC, 1961.

HOHNSTEDT AND SCHAEFFER

Borazine Chemistry

233

authors consider borazine to be about 5 0 % aromatic (7). Despite such differences, there is a remarkable correspondence of physical properties of borazine and benzene (Table I ) .


Table I.

Physical

Properties Borazine

Benzene

80.5 328 216 525 0.63 0.81 7.0 21.4 100 31.1 208 1.00

78.1 353 279 561 0.63 0.81 7.4 21.1 96 31.0 206 1.01

M o l . wt. B. P., °K. M.P.,°K. Critical temp., ° K . Reduced b.p., ° K . L i q u i d density at b . p . , g./cc. H vap./mole, kcal./mole T r o u t o n ' s constant Molecular vol. at b.p., cc. Surface t e n s i o n a t m . p . , d y n e s / c m . Parachor C r y s t a l density a t m . p .

While the properties of derivatives of borazine generally have not been studied as extensively as those of the parent compound, for a number of derivatives the ratio of the absolute boiling point to that of the organic analog is about 0.93, the value for borazine-benzene. Some of the available data are illustrated i n Table I I . Table U. Properties of Borazines Compound

M.P., °C.

Methylborazines Borazine 2?-Monomethylborazine JV-Monomethylborazine B.B'-Dimethylborazine 2?,iV-Dimethylborazine AT.W-Dimethylborazine Β,β',β''-Trimethylborazine ΛΓ,ΛΓ',ΛΓ''-Trimethylborazine Α^Β,Β'-Trimethylborazine JV,B,B'i*,"-Tetramethylborazine Hezamethylborazine Compound

Organic Analog

B.P., °C.

-58.0 -59

(£9,39) Benzene Toluene Toluene m-Xylene o- o r p - X y l e n e m-Xylene Mesitylene Meeitylene Hemimellitene or pseudocumene Isodurene Mellitene

55 87 84 107 124 108 129 134 139

-48 31.5 - 8

158 233

97

R a t i o of B . P . , ° A b s o l u t e Borazine/Organic

M.P., °C.

B.P., °C.

0.93 0.94 0.93 0.92 0.95 or 0.97 0.92 0.91 0.92 0.92 or 0.93 0.92 0.92 Ref.

Halogenoborazines BiFtHN.(CHt)t B«FiNi(CH,), BiFiN.(SiH,), BIC1H,NIH» BICIIHNIH, BiChNtH! B,CliN.(CH,), BiCliNi(CtH,)i BiCliNifCeHn)i BiChN^CeH,), BiCliN^p-CeH*—CHI)I BiChNs(t>-CeH4—OCHi) BiBrHiNiHj ΒιΒπΗΝιΗι Β,ΒΓ,Ν,Η,

( V . p . = 5.9 m m . a t 2 4 . 1 ° C . ) 85 ( V . p . - 2.5 m m . a t 2 4 ° C . ) -34.6 33.0-33.5 83.9-84.5 167 58-60 217-219 273-275 304-307 230-234 -34.8 49.5-50.0 126-128

B-Triethylborazine B-Tributylborazine N-Triethylborazine iV-Tri-n-propylborazine ^"-Triisopropylborazine iV-Tricyclohexylborazine

-46.4-0.5 ( B . P . - 3 4 ° a t 7 microns) -49.6 Glass -6.5 98-99·

(SO) (S6, 42) (S6) (27) (27) (4)

224 109.5 151.9

(27) (27) (28)

122.3 167.1

A l k y l borazines 180

(24,25) (14) (14)

184 225 203

04)

A r y l borazines Β - T r i p h e n y lborazine JV-Triphenylborazine iV-Tri-p-tolylborazine iV-Tri-p-anisylborazine

184-185 158 149-150 127-129

(24,26)

b

(Continued on page 234) In BORAX TO BORANES; Advances in Chemistry; American Chemical Society: Washington, DC, 1961.

ADVANCES IN CHEMISTRY SERIES

234 Table II

(Continued)

N-Trimethyl-B-trialkoxyborazi AT-Trimethyl-fi-triphenoxyborazines

nee, a n d (3). E I ( O R ) I N I ( C H I ) I

Boiling

OR -

methoxy ethoxy n-propoxy isopropoxy n-butoxy feri-butoxy phenoxy

Range

°C.

P* m m .

Melting Range, ° C .

62-65 79.5-80.5 101-103 85-87 130-134 120-125 185-187

0.07 0.10 0.15 0.10 0.30 0.52 0.07

84-87 81-84


B-Trisubstituted JV-Triphenylborazines, Ε Λ ι Ν 8 ( Ο β Η ) ι (9) 6

R

M.P.,°C.

CHt CiH n-CiH t-C»H n-C4H t-C4H CeH» CH»-CHCHi

267-269 169-171 169-171 197-198 129-132 185-187 413-415 9 8 - 99

6

7

7

9

9

» D i f f i c u l t to p u r i f y , some u n c e r t a i n t y a s t o correct M . P . C o m p o u n d a p p a r e n t l y decomposes o n s t a n d i n g . M . P . goes t o l o w e r v a l u e s o n a n y e x c e p t f r e s h l y r e c r y s tallized samples. b

The melting point variation i n trimethylborazines is interesting. The relation of borazine and its derivatives to the corresponding benzene com pounds has stimulated a number of spectral studies and there has been considerable interest i n utilizing borazine chemicals i n a variety of applications which are suggested by consideration of benzene chemistry, as well as b y the nature of borazine itself. Stock found that borazine does not react with oxygen at room temperatures, though it will explode with oxygen in an arc to give B 0 , N , and H 0 . I t dissolves i n water with slow evolution of H and N H , and fresh aqueous solutions of borazine reduce K M n 0 , C u + + to C u , and N i + + to N i . Heating the vapor to 500°C. for 6 hours showed only incomplete decomposition with evolution of hydrogen and formation of a white, nonvolatile solid, ( B N H ) ^ . T o date, relatively little more is known of the chemistry of borazine and much of what is known has been elucidated incidentally t o the development of synthetic procedures. The reason for this relative paucity of information is not hard to identify. T h e synthetic procedure first developed involved the use of hazardous, difficultly obtained materials, which required vacuum line techniques for their manipulation and only small quantities of borazine were obtained even b y workers with the requisite equipment and experience. Stock and his coworkers prepared borazine b y heating boron hydride ammoniates in a bomb tube. After years of experience, the best yields, only about 5 0 % , were ob tained b y heating B H and N H i n a carefully adjusted mole ratio of 1 to 2 (39, Jfi). 2

2

3

2

2

3

4

2

e

3

Β Η .2ΝΗ* 2

200°

6

> B NsH + H

2

>Β Ν Η + H

2

8

e

2-3 hours 180°

Β4Ηιο·4ΝΗ

3

3

3

β

40% yield 200-220°

Β Ηβ·2ΝΗ 2

3

> BaNsHe + H

2

Η hour, 1 a t m .

50% yield Schlesinger and his group at the University of Chicago prepared various B - m e t h y l borazines b y analogous reactions i n which a diammoniate of a methyldiborane, or the corresponding mixture, was heated. iV-Methylated derivatives were prepared b y heating together diborane and methylamine or diborane and methylamine-ammonia In BORAX TO BORANES; Advances in Chemistry; American Chemical Society: Washington, DC, 1961.

HOHNSTEDT AND SCHAEFFER mixtures (81, 82). of reagents used. obtained.

235

Borazine Chemistry

The relative amounts of products depended on relative proportions Yields better than 5 0 % , i n some cases approaching 100%, were

B RiH6 + 2 N H 2

180-200° 8

> B R H N H 3 , B 3 R H N s H + H , etc., 3

2

8

2

3

2

2-6 a t m .

+ B3R3N3H3

B H + 2

e

2RNH

> B H N R3 3

2

3

3

(ammonia also present) —> B H N R + B H N R H + B H N 3 R H 3


R = CH

3

3

3

3

3

3

2

3

3

2

3

Wiberg prepared 5-trimethylborazine and hexamethylborazine b y use of t r i m e t h y l boron (41)330°

3BR, + 3 N H

> B R N H3 + 6CH4

3

3

8

3

20 a t m . 450°

3BR + 3NR 8

> B R N R + 6CH4

3

3

3

S

3

20 a t m .

R = CHs However, within the past decade several new synthetic approaches for preparation of borazine compounds have been developed which do not require the prior preparation of boron hydrides or trimethylborane. The first new approach was that of G . W . Schaeffer, i n which iV-trisubstituted borazines are produced b y the reaction of alkylammonium chloride and lithium boro hydride i n an ether slurry. Addition of ether to the mixed reagents, with the borohy dride i n slight excess of 1 to 1 mole ratio, leads to the evolution of approximately 1 mole of hydrogen per mole of alkylammonium chloride. The hydrogen is then removed along with the solvent by evacuation at reduced pressure. The remaining solid is pyrolyzed. T h e volatile products of the pyrolysis reaction are then passed through a heated zone and the desired borazine is separated from gases issuing from the heated zone (14)ether

> LiCl + B N H R + H

L1BH4 + R N H 3 C I

BNH R 6

pyrolysis

6

> % B3H3N3R3 + 2 H

2

2

R = methyl, ethyl, η-propyl, isopropyl These reactions presumably proceed b y the formation of an amine-borane, which on pyrolysis decomposes, perhaps i n the same stepwise fashion as that established b y Wiberg for the bomb tube reactions he has studied. (H NR)C1 + L1BH4 -> L i C l + (H NR)(BH4) -> H + H R N : B H 3

3

H R N : B H —^> H R N B H 2

3

2

> %

(RNBH)

2

2

3

B3H3N3R3

Preparation of borazine itself b y reaction of L i B H and ammonium chloride i n similar fashion proved to require rather specific conditions to obtain any borazine at all. M o r e recent efforts using carefully regulated conditions have succeeded, and yields as high as 4 2 % were had i n some runs. However, i t was found that borazine could be produced i n useful quantities by the reaction of L i B H and N H C 1 i n the absence of solvents, using a technique generally similar to that employed for the a l k y l borazines. Yields of 30 to 3 5 % could be obtained routinely (22, 27). 4

4

3LiBH + 4

ρ =

3NH4CI

1

atm.

4

> B N H + 9 H + 3LiCl 3

8

e

2

/ around 3 0 0 ° C .

Another line of approach suggested itself after Laubengayer and B r o w n reported the synthesis of B-trichloroborazine b y the reaction of B C 1 and ammonium chloride 3



236

i n refluxing chlorobenzene (4, 6). While attempts to reduce B3CI3N3H3 with L i A l H did not lead to the isolation of the desired B N H , Schlesinger's group established that the reduction of B3CI3N3H3 with L i B H i n b u t y l ether could give satisfactory yields of borazine. Smith, E d d y , and M i l l e r at the N a v a l Research Laboratory extended the method to produce relatively sizable quantities of B N H (13 grams after several runs) (5, 28). 4

3

3

e

4

3

3

e

refluxing

3BCU +

> B3CI3N3H3

3NH C1 4

+ 9HC1

chlorobenzene butyl

B ClaN,H + 3LiBH


3

3

•

4

B3H3N3H3 +

ether

Vi B H « + 3 L i C l 2

B H is a by-product, b u t i t can be handled i n a number of ways, such as b y a b sorption i n a column of N a B H ( O C H ) to generate N a B H . T h i s is attractive, i n that N a B H itself reduces B3CI3N3H3 smoothly when polyethylene glycol dimethyl ethers are used as solvent, and yields i n excess of 9 0 % have been obtained (11, 18). ii B H + N a B H ( O C H , ) , -> N a B H * + B ( O C H , ) 2

e

3

3

4

4

2

E

8

A n s u l 141

BJCIJNJH, + 3NaBH4

> B H3N,H 8

3

4- 3 N a C l +

*/ B H « 2

2

This latter preparative scheme, reduction of B-trichloroborazine with N a B H i n polyethylene glycol ether solvents, has been used to prepare a number of JV-substituted borazines from the corresponding β-trichloro iV-trisubstituted borazines. T h e methyl intermediate was had b y the reaction of methylammonium chloride and B C 1 i n chloro4

3

B3CI3N3RS + 3 N a B H 4 - » B H 3 N , R s 3

+ % B H« + 2

3NaCl

R = methyl, ethyl, cyclohexyl, phenyl, p-tolyl, p-anisyl benzene, and the others were prepared b y using the appropriate amine rather than amine hydrochloride. W e were guided i n this work by the earlier efforts of K i n n e y and coworkers, who first prepared β-trichloroborazines b y interaction of B C 1 with amines (15-17). The reactive Β—Cl bond i n B3CI3N3H3 suggested a convenient method for the preparation of .B-substituted borazines b y reaction with metallo-organic reagents. 5 - T r i m e t h y l , β-triethyl, and 5-triphenylborazines have been prepared from B3CI3N3H3 and the corresponding Grignard reagent. Several research groups have been active i n the synthesis of borazines substituted on nitrogen as well as on boron, by analogous reactions. T h e second equation indicates some of the work reported b y Groszos a n d Stafiej (9). 3

+ 3RMgX -*

B3CI3N3H3

B 3 R 3 N 3 H 3

+ 3MgXCl

R = methyl, ethyl, phenyl B Cl3N,(C H )3 + 3 R M g X 3

e

6

B a R j ^ C e ^ + 3MgXCl

R = phenyl, methyl, ethyl, η-butyl, isobutyl, allyl Ryschkewitsch has reported on reactions of B-trichloro-iV-trimethylborazine. T h e r e action proceeds stepwise to replace one chlorine at a time, and the intermediate com pounds have been isolated i n several cases (10, 26). Aminoborazines have been pre pared b y Gould (8). B,Cl3N,(CH3)3 + R M g X ->

> B C1R*N3(CH )

B C1 RN3(CH )3 3

2

3

3

RMgX

3

8

> BjRjNitCH,), RMgX

Still another synthetic route has been developed b y R u i g h , who has prepared B-trisubstituted borazines from the reaction of excess ammonia with dichloroboranes *δ). 3RBC1 + 9 N H -> B3R3N3H3 + 6 N H 4 C I 2

3

R » butyl, phenyl, /3-chlorovinyl



237

Borazine Chemistry

This method of synthesis has been limited i n application because of the lack of satisfactory syntheses for dichloroboranes. A series of papers by M c C u s k e r describes the synthesis of a variety of alkyldichloroboranes by the reaction of B C 1 with alkylboroxines. Procedures for several aryl dichloroboranes are given also (19). We have outlined general synthetic approaches currently available and have not listed all the applications that have been made or suggested. The earlier synthetic method, in which ammonia and borane are heated, has been adapted to produce as much as 33 grams of pure J?-triethylborazine in one run by carrying out the heating in an autoclave (43). F o r synthesis of N-substituted borazine, JV-trialkylaminoboranes can be prepared by the method described by Koster (18). Downloaded by NORTH CAROLINA STATE UNIV on November 20, 2012 | http://pubs.acs.org Publication Date: June 1, 1961 | doi: 10.1021/ba-1961-0032.ch026

3

450°

3H NB(C H )3 3

2

5

> B (C H5)3N H3 + 6 C H 3

120 grams

2

3

2

48.6 grams crude

5

theoretical amount

(43)

33 grams purified 48.6 grams R N + B E t + 3 H -> R N : B H + 3 C H 3

3

2

3

3

2

e

(18)

The chemical properties of borazine, and its t r i - and hexamethyl derivatives are discussed by Wiberg (39). However, he makes a frequently quoted statement that borazine and its methyl derivatives are thermally stable. While borazine decomposes only slightly after months of storage as a gas i n borosilicate glass containers at room temperature, it undergoes extensive decomposition when stored as a liquid at room temperature. I n such liquid samples, after several days, a glassy solid begins to form and slowly grows i n extent. Later a white solid appears, to which eventually nearly the entire sample is converted. Simultaneously there develops i n the container a considerable amount of gas, which is mostly hydrogen plus a small quantity of diborane. In one case two volatile liquids containing boron, nitrogen, and hydrogen were detected among the decomposition products (28). B N H 3

3

room e

• solids, H , B H , volatile liquids 2

2

6

temperature

(BNH ) X

While we have only limited data as yet concerning the decomposition of liquid borazine at other conditions (11), one must consider the possibility that this complex decomposition proceeds at an increasing rate as borazine is heated above room t e m perature. Thus some of the reported chemistry of borazine probably is obscured b y phenomena accompanying decomposition. The methylborazines studied by Wiberg evidently gave no evidence of decomposition during distillation, but detailed information concerning their behavior on prolonged standing or heating is lacking. However, Russian workers (48) report that B - t r i e t h y l borazine begins to decompose at 100°C. at normal pressure, and the material we have prepared begins to decompose at around 70° when subject to its own vapor pressure. B-Trichloroborazine is reported by Brown to undergo slight decomposition even when carefully stored at room temperature, and to evolve H C l when heated to 100°C. (4). On long periods of standing at room temperature, B3CI3N3H3 appears to undergo polymerization to give less volatile compounds, so that appreciably less volatile m a terial is produced. Experience indicates that a similar change occurs at a faster rate when B3CI3N3H3 is warmed. Thus, i n interpreting available data and i n planning new experiments, one should keep i n mind the potential complications connected with the possibility of decomposition of the reagent borazine. I n addition to the substitution reactions undergone by trichloroborazines, several such reactions have been reported for borazine itself (81). Methyl-substituted borazine undergoes similar reactions (82). In BORAX TO BORANES; Advances in Chemistry; American Chemical Society: Washington, DC, 1961.


238 100°

BjNjHe + B(CH,)s

> B3(CH )H N H 3

2

8

+ B (CH ) HN H

3

3

3

3

2

+ Bs(CH,) NsH

8

3

8

+ H , etc. 2

24 h o u r s 190-200°

BsNjHe - f H N B ( C H s ) 2

> similar products

2

hour

2?-Mono- and dihalogenoborazines have been prepared by substitution using B C 1 or B B r . N o trihalo- compounds were observed (27). B C 1 and B-trimethylborazine 3

3

3

B N H e + BC1 3

3

116 h o u r s

> B C1 HN H + B C1H N H

3

3

3

2

3

2

3

3

3

room temperature

B N H


3

3

+ BBr

e

> B Br H N H + B BrH N H

3

2

3

2

3

3

2

3

3

3

undergo extensive reaction at room temperature to give a variety of products, but this has not been investigated i n detail. Wiberg has reported the preparation of a number of borazines by way of inter mediate compounds prepared by addition reactions of borazines (89). The types of reactions involved may be exemplified by the addition of gaseous H C 1 and H B r to borazine, to give white, nonvolatile, readily hydrolyzable solids. room

BsNjHe + 3HC1

> BaNjHj-SHCl

temperature

> BsCUNiHs + 3 H

2

5 0 ° to 1 0 0 °

room

B N H + 3HBr 3

3

e

> B N H -3HBr 3

temperature

3

> B Br N H + 3H

3

3

3

3

3

2

These solids on heating i n vacuum split out hydrogen to give B-trichloro- and B - t r i bromoborazine, and so are postulated by Wiberg to have the structure analogous to a cyclohexane derivative. H

H

\. /-

\

B

T

^B

M

/

R^

Ν

/Β.

H

I

^Cl

C 1

Η"

B H N H + 3HBr 3

3

8

I

+

. B ^ M '/ B .

H

" >

I Η

3H

2

C l

100°

> HaBraNaH, + 3 H

3

2

A t higher temperatures the halogenoborazines can be produced without isolating the intermediate adducts. I n the case of B-methylborazines similar products are ob tained, but i n these cases Wiberg finds that the ring splits on heating to give an aminoborane, which on further heating loses methane, as illustrated by hexamethylborazine. R 3HC1

B R N R 3

8

3

> B R N R -3HC1

8

8

3

8

>

8

20°

150°

R \

^

Ν—Β

/

/ \

Cl R

\

/

Ν—Β

/

R > (RN—BC1) + C H

\

H

Cl

R = CH

4

450°

H (BaClaNaRa)

3

While excess H C 1 has no effect at room temperature, at higher temperature the intermediate aminoborane adds H C 1 to give a dichloroborane and an amine h y d r o chloride. R R \ ^

H

/

_ /

HCl

-B

_

> H RN:BRC1 2

\

Cl

150°

HC1 2

> BRC1 + (RNH,)+C12

330°



239

Borazine Chemistry

F o r borazine and iV-methylborazine reaction with water is analogous to that w i t h H C l — t h a t is, at low temperature a trihydrate is formed; at intermediate temperature itarihydroxyborazines are formed from a stoichiometric amount of water, and with excess water at higher temperatures, the compounds are hydrolyzed completely. B3H3N3R3

+ 3H 0

B H N R3-3H 0

2

3

3

2

3

100°

B3H3N3R3

+ 3H 0 2

> B (OH) N R3 3

3

3

150°

B3H3N3R3

+ 6H 0 2

> 3B(OH) +

3NRH

8

2

+ 3H

2


R = CH« (β-Trihydroxyborazines can be had from the action of water on chlordborazines, at least i n some cases.) I n the case of 5-methylborazine, Wiberg found that at conditions which would be expected to give hydroxyborazines, a boroxine ring is formed. Wiberg explains this on the basis of splitting of the adduct to give an analog of v i n y l alcohol (I) which establishes equilibrium with its tautomeric acetaldehyde analog ( I I ) , which then trimerizes t o a boroxine ring. R B R N H 3

3

3

3

+

3H 0 2

^2!—„

>—B'

/

B

^0

I I RB^^^BR

ioo°

Η

o

. H N:B=Q 3

·3ΝΗ

3

R=CH

3

OH (D

(II)

Wiberg reports some further observations on reactions of borazine, such as those with ammonia, methanol, amines, alkyl halides, and elementary halogens. However, few experimental data are presented and in some cases the reactions may have to be reconsidered on the basis of additional information as i t becomes available. F o r ex ample, H a w o r t h and Hohnstedt (12) discuss the reaction of borazine with methanol. M o r e and more data concerning the chemistry of borazine are being made known as various workers report their results i n this field. The synthesis of JV-trimethyl-£trialkoxy- and -triphenoxyborazines has been reported b y Bradley, Ryschkewitsch, and Sisler (8). Niedenzu and Dawson (23) have described the preparation of B - t r i a m i n o borazines through the interaction of a tertiary amine with the addition product of BCI3 and a primary amine. They have also prepared 5-triaminoborazines b y reacting an amine with an aminodichloroborane. Their application of the Friedel-Crafts reac tion to Z?-trichloroborazine i n benzene-chlorobenzene leads to good yields of £-triphenylborazine. Other individuals and groups throughout the world are disclosing their results i n the widening field of borazine chemistry (1, 2, 6, 8, 20-22, 33, 87, 88), so that the t a b u lated data and list of references do not represent a complete compilation of available information. LITERATURE CITED (1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

Becker, H . J., Z. anorg. u. allgem. Chem. 289, 262 (1957). Becker, H . J., Frick, S., Z. physik. Chem. (Frankfurt), Neue Folge, 12, 241 (1957). Bradley, M . J., Ryschkewitsch, G. E., Sisler, Η. Η., J. Am. Chem. Soc. 81, 2635 (1959). Brown, C. Α., Laubengayer, A. W., Ibid., 77, 3699 (1955). Eddy, L. B., Smith, S. H., Jr., Miller, R. R., Ibid., 77, 2105 (1955). Emeleus, H. J., Videla, G. J., Proc. Chem. Soc. 1957, 288. Goubeau, J., Keller, Η., Z. anorg. u. allgem. Chem. 272, 303 (1953). Gould, J. R., U . S. Patent 2,754,177 (1956). Groszos, S. J., Stafiej, S. F., J. Am. Chem. Soc. 80, 1357 (1958). Harris, J . J., Ryschkewitsch, G. E., Sisler, Η. H., Abstracts of Papers, Division of Physical and Inorganic Chemistry, 132nd Meeting, ACS, September 1957, p. 9S.


240



(11) (12) (13) (14)

Haworth, D. T., Ph.D. thesis, St. Louis University, 1959. Haworth, D. T., Hohnstedt, L. F., J. Am. Chem. Soc. 81, 842 (1959). Hohnstedt, L. F., Ph.D. thesis, University of Chicago, 1955. Hough, W. V., Schaeffer, G. W., Dzurus, Marcelline, Stewart, A. C., J. Am. Chem. Soc. 77, 864 (1955). (15) Jones, R. G., Kinney, C. R., Ibid., 61, 1378 (1939). (16) Kinney, C. R., Kolbezen, M . T., Ibid., 64, 1584 (1942). (17) Kinney, C. R., Mahoney, C. L., J. Org. Chem. 8, 526 (1943). (18) Koster, R., Angew. Chem. 69, 94 (1957). (19) McCusker, P. Α., Ashby, E . C., Makowski, H . S., J. Am. Chem. Soc. 79, 5179, 5182 (1957). (20) Mikhailov, B. M., Kostrama, T. V., Izvest. Akad. Nauk S.S.S.R. Otdel. Khim. Nauk 1957, 1125-7. (21) Mikhailov, Β. M., Shchegokva, Ibid., 1957, 1123-5. (22) Mikheeva, V. I., Markina, V. Yu., Zhur. Neorg. Khim. 1, 2700 (1956). (23) Niedenzu, Kurt, Dawson, J. W., Division of Inorganic Chemistry, 135th meeting, ACS, Boston, Mass., April 1959, p. 34M. (24) Ruigh, W. L., Gunderloy, F. C., Division of Organic Chemistry, 129th meeting, ACS, Dallas, Tex., April 1956, p. 40N. (25) Ruigh, W. L., et al., "Research on Boron Polymers," Wright Air Development Center Tech. Repts. 55-26, Part I (March 1955), Part II (May 1955), Part III (December 1955), Part IV (September 1956). (26) Ryschkewitsch, G. E., Harris, J. J., Sisler, H . H., J. Am. Chem. Soc. 80, 4515 (1958). (27) Schaeffer, G. W., Schaeffer, Riley, Schlesinger, H . I., Ibid., 73, 1612 (1951). (28) Schaeffer, R. O., Steindler, Martin, Hohnstedt, L . F., Smith, H . S., Jr., Eddy, L . B., Schlesinger, H . I., Ibid., 76, 3303 (1954). (29) Schlesinger, H. I., Burg, A. B., Chem. Revs. 31, 1 (1942). (30) Schlesinger, H . I., Finch, Α., Kerrigan, J., Murib, J., Office of Naval Research, Ann. Tech. Rept., July 31, 1956, Contract Ν 6 ori-02010, Project N356-255, p. 29. (31) Schlesinger, Η. I., Horwitz, Leo, Burg, A. B., J. Am. Chem. Soc. 58, 409 (1936). (32) Schlesinger, H. I., Ritter, D. M., Burg, A. B., Ibid., 60, 1296 (1938). (33) Scott, L. B., Morris, R.C.,U. S. Patent 2,821,463 (1958). (34) Stock, Alfred, Pohland, Erich, Ber. 59B, 2210 (1926). (35) Stock, Alfred, Wierl, Raimund, Z. anorg. u. allgem. Chem. 203, 288 (1931). (36) Sujishi, Sei, Wirts, Samuel, J. Am. Chem. Soc. 79, 2447 (1957). (37) Turner, H. S., Warne, R. T., Chem. and Ind. (London), 1958, 526. (38) Videala, G. F., Bühler, M . F., Proc. International Conference on Peaceful Uses of Atomic Energy, Vol. 8, 619 (1954). (39) Wiberg, Egon, Naturwissenschaften 35, 182, 212 (1948). (40) Wiberg, Egon, Bolz, Arthur, Ber. 73B, 209 (1940). (41) Wiberg, Egon, Hertwig, Karl, Z. anorg. u. allgem. Chem. 255, 141 (1947). (42) Wiberg, Egon, Horeld, Gabriel, Z. Naturforsch. 6b, 388 (1951). (43) Zhigach, A. F., Kazakova, Ye. B., Krongauz, Ye. S., Doklady. Akad. Nauk S.S.S.R. 111, 1029 (1956).


Borazine Chemistry - Advances in Chemistry (ACS Publications)

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