Organic compounds -- part of the class 532-570 series – Organic compounds – Unsubstituted hydrocarbyl chain between the ring and the -c-...
Reexamination Certificate
1999-09-30
2001-10-02
Shah, Mukund J. (Department: 1611)
Organic compounds -- part of the class 532-570 series
Organic compounds
Unsubstituted hydrocarbyl chain between the ring and the -c-...
C540S556000
Reexamination Certificate
active
06297372
ABSTRACT:
TECHNICAL FIELD
The present invention relates to hexanitrohexaazaisowurtzitane and a process for preparing the same.
BACKGROUND ART
As compounds having hexaazaisowurtzitane skeletons, various arylmethyl group-containing hexaazaisowurtzitane derivatives are known which are obtained by condensation of arylmethylamines and glyoxal (J. Org. Chem., vol. 55, 1,459-1,466, 1990). Tetraacetyldibenzylhexaazaisowurtzitane is known as an acyl group-containing hexaazaisowurtzitane compound and is reported to be a precursor of hexanitrohexaazaisowurtzitane which is a material for explosives (The Militarily Critical Technologies List, Office of the Under Secretary of Defense for Acquisition, 12-22, October 1992 and Tetrahedron, Vol. 51, No. 16, 4711-4722, 1995). Further, there are known ethyl group-containing hexaazaisowurtzitane derivatives such as tetraacetyl-diethylhexaazaisowurtzitane and the like (Tetrahedron, Vol. 51, No. 16, 4711-4722, 1995) and there are also known trimethylsilylethyloxycarbonyl group-containing hexaazaisowurtzitane derivatives (JP-A-6-321962). There are known benzyl and/or ethyl group-containing hexaazaisowurtzitane derivatives other than the above-mentioned tetraacetyldibenzylhexaazaisowurtzitane, tetraacetyldiethylhexaazaisowurtzitane.
The above-mentioned hexaazaisowurtzitane derivatives having acyl groups easily substitutable with nitro groups are useful as precursors of polynitrohexaazaisowurtzitane derivatives for high-performance explosives; however, use of the above-mentioned derivatives as precursors of the nitro compounds has problems. For example, since by-products such as nitrated aromatic compounds are produced in nitration of the benzyl group-containing hexaazaisowurtzitane derivatives, it is complicated to isolate and purify therefrom hexanitrohexaazaisowurtzitane, the target compound of the present invention. On the other hand, hydrochloric acid, i.e., a strong acid, which is produced during preparation of trimethylsilylethyloxycarbonyl group-containing hexaazaisowurtzitaines, causes the decomposition of hexabenzylhexaazaisowurtzitane that is the starting material in the process. It is reported that hexanitrohexaazaisowurtzitane is obtained by nitration of the tetraacetyldibenzylhexaazaisowurtzitane, but no detailed description is found on its method of preparation (Tetrahedron, vol. 51, No. 16, 4,711-4,722, 1995). It is further reported to be difficult to prepare hexanitrohexaazaisowurtzitane by nitration of tetraacetyldiethylhexaazaisowurtzitane (Tetrahedron, vol. 51, No. 16, 4,711-4,722, 1995).
Therefore, it has been long desired to develop a process for preparing hexanitrohexaazaisowurtzitane in a high yield by use of an acyl group-containing hexaazaisowurtzitane derivative. It is also an object of the present invention to prepare hexanitrohexaazaisowurtzitane in a high yield by use of hexaazaisowurtzitane derivatives.
DISCLOSURE OF THE INVENTION
The inventors have achieved these and other objects according to these and other objects according to the present invention, which comprises the discovery of a commercially advantageous process for preparing hexanitrohexaazaisowurtzitane.
The present invention provides a nitro group-containing hexaazaisowurtzitane derivative and a process for preparing said derivative, which is represented by the following general formula (I):
W A
n
N
(6−n)
(I)
wherein n is an integer of 4 or 5, A is an acyl group having 1-10 carbon atoms with each acyl group being the same as or different from one or more of the others, N is a nitro group and W is a hexavalent hexaazaisowurtzitane residue represented by the following formula (II):
Further, the present invention provides a nitroso group-containing hexaazaisowurtzitane derivative and a process for preparing said derivative, which is represented by the following general formula (III):
W A
n
NS
(6−n)
(III)
wherein n is an integer of 4 or 5, A is an acyl group having 1-10 carbon atoms with each acyl group being the same as or different from one or more of the others, NS is a nitroso group and W is a hexavalent hexaazaisowurtzitane residue represented by the following formula (II):
Any acyl group may be acceptable as acyl group A in the above formulae (I) and (III) so long as it has 1 to 10 carbon atoms. As acyl group A, there may be acetyl, formyl, propionyl, butyryl, isobutyryl, valeryl, hexanoyl, 2-phenylacetyl or the like. Preferably, A may be acyl groups having 1-5 carbon atoms such as formyl, acetyl, propionyl, butyryl, valeryl and the like and more preferably, A may be acyl groups having 2-4 carbon atoms such as acetyl, propionyl, butyryl and the like. In the above formulae (I) and (III), each of the n acyl groups may be the same as or different from one or more of the others.
Each of the hexaazaisowurtzitane derivatives may take the form of any of various isomers differing in the positions of acyl, nitro and nitroso groups thereof; however, any of such isomers may be used in accordance with the present invention.
Hereinbelow, descriptions will be given of methods for preparing hexaazaisowurtzitane derivatives represented by formulae (I) and (III).
The nitro group-containing hexaazaisowurtzitane derivative of general formula (I), from which hexanitrohexaazaisowurtzitane is prepared, may be prepared by nitration of W A
m
H
(6−m)
as shown in the following reaction formula (1):
W A
m
H
(6−m)
→W A
n
N
(6−n)
(1)
wherein m is an integer of 4-6, n is integer of 4 or 5, A is an acyl group having 1-10 carbon atoms with each acyl group being the same as or different from one of more of the others, H is a hydrogen atom, N is a nitro group and W is a hexavalent hexaazaisowurtzitane residue.
Meanwhile, the nitroso group-containing hexaazaisowurtzitane derivative represented by general formula (III) may be prepared by nitrosation of W A
n
H
(6−n)
as shown in the following reaction formula (2):
W A
n
H
(6−n)
→W A
n
NS
(6−n)
(2)
wherein n is an integer of 4 or 5, A is an acyl group having 1-10 carbon atoms with each acyl group being the same as or different from one or more of the others, H is a hydrogen atom, NS is a nitroso group and W is a hexavalent hexaazaisowurtzitane residue.
Any acyl group-containing hexaazaisowurtzitane derivative represented by W A
n
H
(6−n)
or W A
m
H
(6−m)
in the above reaction formula (1) or (2) may be used as a starting material, regardless of its method of preparation. It is, however, preferable to use W A
n
H
(6−n)
or W A
m
H
(6−m)
which is prepared by reductive dearylmethylation of W B
6
in the presence of an acylating agent and further reductive dearylmethylation of the resultant product in the absence of an acylating agent, for example, as described in PCT publication No. W096/23792. The process for preparing the above-mentioned starting materials will be given in more detail later.
The acyl groups of the hexaazaisowurtzitane derivatives w A
n
H
(6−n)
and W A
m
H
(6−m)
which are the starting materials in the reaction formulae (1) and (2) are those having 1-10 carbon atoms, in which each acyl group may be the same as or different from one or more of the others. Examples of the acyl groups include acetyl, formyl, propionyl, butyryl, isobutyryl, valeryl, hexanoyl, 2-phenylacetyl and the like. Preferred acyl groups are those having 1-5 carbon atoms such as formyl, acetyl, propionyl, butyryl, valeryl and the like and more preferred acyl groups are those having 2-4 carbon atoms such as acetyl, propionyl, butyryl and the like.
Each of these hexaazaisowurtzitane derivatives may comprise any of various isomers according to difference in the positions of acyl groups and hydrogen atoms thereof; however, any of such isomers may be used according to the present invention.
The derivatives represented by the formula W A
m
H
(6−m)
includes W A
4
H
2
, W A
5
H
1
and W A
6
, which may be used independently or as a mixture of two or more.
As the nitrating agent for the nitration process of rea
Kawabe Shuji
Kodama Tamotsu
Miya Hiroshi
Miyake Nobuhisa
Asahi Kasei Kabushiki Kaisha
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Reid Steven M.
Shah Mukund J.
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