Photochemical Chlorocarbonylation: Simple Synthesis of

Chapter 6

Photochemical Chlorocarbonylation: Simple Synthesis of Polynitroadamantanes and Polynitrocubanes Downloaded by UNIV OF CALIFORNIA SAN DIEGO on May 20, 2013 | http://pubs.acs.org Publication Date: April 24, 1996 | doi: 10.1021/bk-1996-0623.ch006

1

1

1

A. Bashir-Hashemi , Jianchang Li , Paritosh R. Dave , and Nathan Gelber 2

1Geo-Centers, Inc., 762 Route 15 South, Lake Hopatcong, NJ 07849 U.S. Army Research, Development, and Engineering Center, Picatinny, NJ 07806-5000 2

A novel photochemical methodology for the selective functionalization of adamantane and cubane has been developed. In this method, versatile chloro-carbonyl groups, precursors to nitro groups, are introduced at the 1,3,5,7- positions of the adamantane and cubane skeletons leading to efficient syntheses of 1,3,5,7-tetranitroadamantane and 1,3,5,7-tetranitrocubane. Polynitrocage molecules are central to the current efforts aimed at the development of new energetic materials to meet modem requirements for fuels, propellants, and explosives. These systems are particularly attractive because strain energy incorporated in the cage combined with the accumulation of nitro groups tend to bolster energy output, while the molecular compactness produces high density materials favorably increasing detonation velocity. Simultaneously, high crystal density materials are advantageous in volume-limited applications^ ). Although only a relatively few polynitropolycyclic compounds are known, reports describing the successful synthesis of members of this class of materials are appearing with increasing frequency(7 ). Experimental verification of the theoretical predictions regarding the usefulness of these high-energy, high-density compounds as fuels or explosives awaits the accumulation of sufficient amounts of the necessary test compounds. There has been renewed interest in the chemistry of polysubstituted adamantanes since some of its derivatives, particularly nitroadamantanes, have shown promise as high density energetic materials(2). Several synthetic methods have been applied for the synthesis of nitroadamantanes. The direct nitration of adamantane with nitric acid leads to the formation of nitrate esters of substituted adamantanols(i). Photochemical reactions using or N 0s(5) give mixtures of products and produce 1-nitroadamantane as a minor product. Only recently, Olah and his coworkers have obtained 1-nitroadamantane in 60% yield from the slow reaction of adamantane with nitronium tetrafluoroborate at room temperature in purified nitrile-free nitromethane(6). No evidence of any dinitroadamantane was obtained under excessive concentration of the nitrating reagent.

N2O4OO

2

0097-6156/96/0623-0051$15.00/0 © 1996 American Chemical Society In Nitration; Albright, L., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1996.

52

NITRATION

N0

2

N0 BF 2

4

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on May 20, 2013 | http://pubs.acs.org Publication Date: April 24, 1996 | doi: 10.1021/bk-1996-0623.ch006

Adamantane

ù Nitroadamantane

In general, polynitroadamantanes have been obtained by introducing the proper functionalities on the adamantane skeleton which then can be converted to the corresponding nitro groups(7-2). The methodology used in the recent synthesis of 1,2,2-trinitroadamantane exemplifies the introduction of nitro groups on tertiary and secondary carbon atoms on the adamantane skeleton(7). COOH

COCl

Trinitroadamantane

The starting functionalized adamantane for the above synthesis, 2oxoadamantane carbonyl chloride is readily available by cyclization of 3,3,1bicyclononanedicarboxylic acid(S). The carbonyl chloride function was converted to the corresponding amine via the Curtius rearrangement of the derived acyl azide. Oxidation of the amino group was using dimethyldioxirane yielded nitroadamantanone. The carbonyl group was converted to the geminal dinitro function by oxidative nitrolysis of the derived oxime. The order of conversion of the functional groups on adjacent carbon atoms was chosen so as to avoid the intermediacy of a 1,2-amino nitro grouping, which is known to lead to cage fragmentation in other systems. This methodology also represents the first example of the conversion of vicinal functional groups on any polycycle to vicinal nitro groups. The conversion of multiple carbonyl functionality to geminal dinitro groups has been successfully achieved in the synthesis of 2,2,4,4,6,6hexanitroadamantane, the most highly nitrated adamantane known to date(9). The synthesis of 1,3,5,7-tetranitroadamantane from adamantane was accomplished in multiple synthetic steps(2). Tetrahalogenation of adamantane at bridgeheads followed by Photo-Ritter reaction of tetraiodoadamantane with acetonitrile introduced four acetamide groups on the adamantane skeleton.

In Nitration; Albright, L., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1996.

6. BASHIR-HASHEMI ET AL.

Photochemical Chlorocarhonylation

53

Subsequent hydrolysis of the tetraamide with hydrochloric acid and then oxidation with permanganate gave tetrahedrally nitrated l,3,5,7-tetranitroadamantane(70). As interesting as this approach looks, the multi-step synthesis process and low yields limit the practical large-scale synthesis of this compound. Br


[|

J

Bn/AlÇb

If

Adamantane

^

, CH I /A1

I

2

r

( V |

2

* I CH3CN, H 0 , η υ 2

ΝΟ2

* NHCOCH3

NH3CI

0

2

N

^ J ^ ^ N 0

2

θ2Ν

CIH3N7LI

H J C O C H N - T H ^ ^ N H C O C I ^

^1

/

NH3CI

CIH3N

H3COCHN

Tetranitroadamantane

In the present work, a different approach for the synthesis of tetranitroadamantane was taken starting from 1,3,5,7-tetracarbonyladamantane. Several synthetic methods have been applied to the synthesis of adamantane tetracarboxylic acids(77-72J. The most recent modified method for the synthesis of Td-tetraester 3 requires multiple synthetic steps, requiring high-pressure, hightemperature bomb reactions, and therefore, is greatly limited for scaled-up production(72J.

°i/ ™^ COOMe

MeOOC^^cOOMe MeOOC

°

Meerwein ester

COOMe

M e O O C

£J^^

MeOOC

Ο

COOMe

iHimai

COOMe

MeOOC^H;^

rh

C O O M e

MeOOC 3

Very recently, the efficient photochemical chlorocarbonylation of a series of cyclic and acyclic carbonyl compounds with oxalyl chloride has been reported(73). Several carboxycubanes have been synthesized by employing this photochemical process(74). Here, the one-pot synthesis of 1,3,5,7-tetrakis(chlorocarbonyl)adamantane 2 from commercially-available 1-adamantanecarboxylic acid 1 and oxalyl chloride, and its conversion to 1,3,5,7-tetranitroadamantane 6 is reported. Photochemical reaction of adamantane with oxalyl chloride produced only a small amount (h^

/ J ^ y

JY

Ί

C10 y4--^cOCI C

COOMe MeOH

^

f f |

MeCK)C^J~^cOOMe

When commercially available 1,3-adamantanedicarboxylic acid 4 was treated with oxalyl chloride under U V light. After l h , the reaction mixture was concentrated and triturated with cold ether to give compound 2 in 40% yield. Tetraester, 3, was obtained by methanolysis of the reaction mixture and isolated by triturating the crude mixture with methanol. As expected, the GC-MS of the reaction mixture showed a ratio of 3 to unidentified products of 60/40.


6. BASHIR-HASHEMI ET AL.

Photochemical Chlorocarbonylation

ÇOOH

55

ÇOOMe 1. (COCl)2,hO

2. MeOH M e O O C ^ J - - 7 - c O O M e


MeOOC

Tetrakis(chlorocarbonyl)adamantane 2 (18) was converted directly to the corresponding adamantane tetraisocyanate 5 using azidotrimethylsilane. 1,3,5,7Tetranitroadamantane 6 was obtained in 40-50% yield from the oxidation of compound 5 with wet dimethyldioxirane (DMDO). çoa Il

NO2

NCO I

™

S I N

3 w

ClOC

If

I

DMDO

OCN

^

\(

Π

OaN

1,3,5,7-Tetranitroadamantane exhibits moderate power output and low shock and impact sensitivity. It has a very high thermal stability (DSC= 350 °C) and high crystal density(d= 1.63 g / cm^). This methodology has successfully been applied to the synthesis of 1,3,5,7tetranitrocubane(74,79). Photochemical reaction of cubane carboxylic acid with oxalyl chloride gave 1,3,5,7-tetrakis (chlorocarbonyl)cubane in 60% yield. The solid product was treated with azidotrimethylsilane in chloroform, and, after heating the reaction mixture for l h under reflux, the resulting tetraisocyanate was treated with wet dimethyldioxirane to give tetranitrocubane in 50% yield.

,COOH

COCI

(COCl)2,m)

ClOC

Cubanecarboxylic acid

COCI

0 N 2

N0

2

1,3,5,7-Tetranitrocubane

The photochemical chlorocarbonylation of nitrocubane gives predominantly 3, 5, 7-tris(chlorocarbonyl)nitrocubane, emphasizing the importance of polar effects in determining the regioselectivity in this class of reactions. As expected, tetranitrocubane did not react under a variety of reaction conditions. In conclusion, a novel photochemical methodology for the selective functionalization of adamantane and cubane has been developed. In this method, versatile chlorocarbonyl groups, precursors to nitro groups, are introduced at the 1,3,5,7- positions of the adamantane and cubane skeletons leading to efficient syntheses of 1,3,5,7-tetranitroadamantane and 1,3,5,7-tetranitrocubane. In this approach, the direct placement of four acyl chlorides on adamantane and on cubane obviates the use of reagents such as thionyl chloride, necessary for converting acid functions to acyl chlorides (20). Additionally, the excess oxalyl chloride can be recycled and reused continuously. This methodology may also be advantageously extended to other cage systems.



56

NITRATION

1,3,5,7-Tetranitrocubane

Acknowledgments: This article is respectfully dedicated to Dr. Everet Gilbert, who originated nitrocage chemistry at A R D E C . We sincerely thank Dr. N . Slagg for his support and inspiration throughout this work. Financial support provided by A R D E C to GEO-CENTERS, INC. is gratefully acknowledged. References: 1. Marchand, A. P.; Tetrahedron, 1988, 44, 2377. Bashir-Hashemi, Α.; Iyer, S.; Slagg, N.; Alster, J. Chem. & Industry, July 17, 1995, 551. 2. Sollott, G. P.; Gilbert Ε. E. J. Org. Chem. 1980, 45, 5405; also see Chemistry of EnergeticMaterials;G.A. Olah; D.R. Squire; Ed, Academic Press, Inc., San Diego, CA, 1991. 3. Moiseev, I. K.; Klimochkin, Yu. N.; Zemtsova, M. N.; Trakhtenberg, P. L. J.Org. Chem. USSR 1984, 20, 1307. 4. Umstead, M. E., Lin, M. C. Appl. phys. 1986, B39, 61. 5. Tabushi, I.; Kojo, S., Yoshida, Z. Chem. Lett. 1974, 1431. 6. Olah, G. Α.; Ramaiah, P.; Rao, C. B.; Sandford, G.; Golam, R.; Trivedi, N. J.; Olah, J. A. J. Am. Chem. soc. 1993,115,7246. 7. Dave, P.R.; Axenrod, T.; Qi, L.; Bracuti, A. J. Org. Chem. 1995, 60, 1895. For similar examples see: Archibald, T.; Baum, K. J. Org. Chem. 1988, 53, 4645; Dave, P. R.; Ferraro, M.; Ammon, H. L.; Choi, C. S. J. Org. Chem. 1990, 55, 4459. 8. Peters, J.A.; Remijnse, J.D.; van der Wiele, Α.; van Bekkum, H. Tetrahedron Lett. 1971, 3065. 9. Dave, P.R.; Bracuti, Α.; Axenrod, T.; Liang, B. Tetrahedron 1992, 28, 5839. 10. For an improved synthesis of tetranitroadamantane using sodium percarbonate as oxidant see: Zajac, Jr. W. W.; Walters, T. R.; Woods, J. M. J. Org. Chem., 1989, 54, 2468. 11. Stetter, H.; Bander, O.-E.; Neumann, W. Chem. Ber. 1956, 89, 1922. Landa, S.; Kamvcek, Z. Collect. Czech. Chem. Commun. 1959, 24, 4004. 12. Newkome, G. R.; Nayak, Α.; Behera, R.K.; Moorefield, C.N.; Baker, G.R. J. Org. Chem. 1992, 57, 358. 13. Bashir-Hashemi, Α.; Hardee, J.R.; Gelber, N.; Qi,L.; Axenrod, T. J. Org. Chem. 1994, 59, 2132. 14. Bashir-Hashemi, A. Angew. Chem. Int. Ed. Engl. 1993, 32, 612. BashirHashemi, Α.; Li, J.; Gelber, N.; Ammon, H. J. Org. Chem. 1995, 60, 698.


6. BASHIR-HASHEMI ET AL. 15.

16.


17. 18.

19. 20.

Photochemical Chlorocarbonylation

57

For a similar approach see.; Tabushi, I.; Hamuro, J.; Oda, R. J. Org. Chem. 1968, 33, 2108. For photoacetylation of adamantanes see; Fukunishi, K., Kohno, Α., Kojo, S., J. Org. Chem. 1988, 53, 4369. March, J. Ed. Advanced Organic Chemistry, Fourth Edition, Wiley Interscience, New York, 1992, pp 684-685. For parameters determining the regioselectivity of radical reactions see; Raymond C. Fort, Jr. Ed. Adamantane, the Chemistry of Diamond Molecules, Marcel Dekker, Inc. New York, NY 1976, pp 233-265. Bashir-Hashemi, Α.; Li, J.; Gelber, N. Tetrahedron Letters, 1995, 36, 1233. For other uses of this compound in dendrimers see; Newkome, G.R., Moorefield, C.N., Baker, G.R., Aldrichimica Acta, 1992, 25(2), 31, as diamandoid molecules; Ermer, O. J. Am. Chem. Soc. 1988, 110, 3747, and in combinatorial chemistry; Carell, T.; Wintner, E.A.; Bashir-Hashemi, Α.; Rebek, Jr. J. Angew. Chemie, Int. Engl. 1994, 20, 2059. Eaton, P. E.; Xiong, Y.; Gilardi, R. J. Am. Chem. Soc. 1993, 115, 10195. There have been occasional explosions reported using this method. All cubane and adamantane derivatives prepared in this article are relatively stable at room temperature. Nevertheless, care should be taken when handling these energetic materials.

RECEIVED September 26,

1995


Photochemical Chlorocarbonylation: Simple Synthesis of

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