Patent Number: 6,310,204

Title: 5,5-bis(difluoramino)hexahydro-1,3-dinitropyrimidine (RNFX) and certain electronegatively substituted pyrimidines

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.

Inventors: Chapman; Robert Dale (Ridgecrest, CA), Nguyen; Ba Van (Tewksbury, MA)

Assignee: The United States of America as represented by the Secretary of the Navy

International Classification: C07D 239/04 (20060101); C07D 239/06 (20060101); C07D 239/00 (20060101); C07D 239/10 (20060101); C07D 239/18 (20060101); C07D 239/22 (20060101); C07D 239/04 (); C07D 239/06 (); C07D 239/10 ()

Expiration Date: 10/30/2018