The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2001
Filed:
Feb. 16, 2000
Robert Dale Chapman, Ridgecrest, CA (US);
Ba Van Nguyen, Tewksbury, MA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
Calculated performance improvements are expected from a particularly new class of compounds, geminal-bis(difluoramino)-substituted heterocyclic nitramines, when formulated into explosives and propellants. This invention involves novel and nonintuitive methods for the preparation of certain derivatives of 2,2-bis(difluoramino)-N-nitro-1,3-propanediamine which are suitable precursors leading to 5,5-bis(difluoramino)hexahydro-1,3-dinitropyrimidine (RNFX). The invention also involves novel and nonintuitive methods for the preparation of RNFX, a specific member of a general class of compounds with the substructure 2,2-bis(difluoramino)-N-nitro-1,3-propanediamine. RNFX is produced by the use of key intermediates, including tetrahydropyrimidin-5(4H)-ones, which allow formation of the target structural subcomponent, 2,2-bis(difluoramino)-N-nitro-1,3-propanediamine, and a more specific substructure of 2,2-bis(difluoramino)-N,N′-dinitro-1,3-propanediamine. The method of making RNFX, generally, comprises reacting with a difluoramine source, a tetrahydro-1,3-disulfonylpyrimidin-5(4H)-one; reacting with a nitronium source, the resultant 5,5-bis(difluoramino)hexahydro-1,3-disulfonylpyrimidine; N-desulfonation with a nucleophile; cyclization with a formaldehyde equivalent; and recovering said 5,5-bis(difluoramino)hexahydro-1,3-dinitropyrimidine—after “2,2-bis(difluoramino)-N,N′-dinitro-1,3-propanediamine.”In addition, this invention involves 5,5-bis(difluoramino)hexahydropyrimidine derivatives, related geminal-bis(difluoramino)alkylene derivatives, and novel precursors to these new derivatives, by the use of certain novel key intermediates.