One-pot process for preparation of ammonium and hydroxyl ammonium derivatives of bis 5,5′-tetrazole-1,1′-dihydroxide
Inventors
Damavarapu, Reddy S. • Duddu, Raja G.
Assignees
Leidos Inc • United States Department of the Army
Publication Number
US-9643937-B1
Publication Date
2017-05-09
Expiration Date
2036-03-31
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
A one-pot process for preparing ammonium and hydroxylammonium salts of bis 5,5′-tetrazole-1,1′-dihydroxide, specifically, diammonium bis 5,5′-tetrazole-1,1′-diolate (ABTOX) and dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50). The process requires the reaction of sodium azide, dichloroglyoxime, HCl in dioxane solution to form bis 5,5′-tetrazole-1,1′-dihydroxide and treating this product with either ammonium chloride to produce ABTOX or hydroxylamine hydrochloride to produce TKX-50.
Core Innovation
The invention discloses a one-pot process for preparing ammonium and hydroxylammonium salts of bis 5,5′-tetrazole-1,1′-dihydroxide, specifically diammonium bis 5,5′-tetrazole-1,1′-diolate (ABTOX) and dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50). The process involves reacting sodium azide and dichloroglyoxime in the presence of hydrochloric acid dissolved in dioxane to form bis 5,5′-tetrazole-1,1′-dihydroxide which is then treated with ammonium chloride or hydroxylamine hydrochloride to produce ABTOX or TKX-50, respectively.
The problem addressed by the invention is the dangerous and hazardous nature of previously reported processes for producing bis 5,5′-tetrazole-1,1′-dihydroxide based salts. Earlier methods require the use of toxic reactant materials such as chlorine gas and hydrogen chloride gas, involve highly sensitive and primary explosive intermediates like diazidoglyoxime, and employ flammable solvents like diethyl ether. These factors cause safety risks and operational challenges, especially for large scale preparation, due to vague reaction parameters and hazardous conditions.
This invention provides an improved process that eliminates the use of toxic gases chlorine and hydrogen chloride in gaseous form, and avoids flammable solvents. It introduces a safe and simplified reaction sequence controlling temperature and reagent addition, culminating in a one-pot preparation method that yields the desired ammonium and hydroxylammonium derivatives with improved safety and reliability. The process uses a commercially available solution of hydrochloric acid in dioxane and replaces prior hazardous steps with controlled additions and milder conditions.
Claims Coverage
The patent includes three independent claims covering a one-pot process to prepare bis 5,5′-tetrazole-1,1′-dihydroxide and its ammonium and hydroxylammonium derivatives.
One-pot synthesis of bis 5,5′-tetrazole-1,1′-dihydroxide
The process comprises adding sodium azide to a solution containing dichloroglyoxime, stirring at less than 15° C., then adding hydrochloric acid dissolved in dioxane while maintaining temperature below 15° C., mixing with water, and isolating solid bis 5,5′-tetrazole-1,1′-dihydroxide by removing liquid.
One-pot production of diammonium bis 5,5′-tetrazole-1,1′-diolate (ABTOX)
Starting from the bis 5,5′-tetrazole-1,1′-dihydroxide product, water is added and heated to form a clear homogeneous solution, an aqueous ammonium chloride solution is reacted with it to form ABTOX, and the solid ABTOX product is separated from the solution.
One-pot production of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50)
From the bis 5,5′-tetrazole-1,1′-dihydroxide product, water is added and heated to a clear homogeneous solution, followed by addition of hydroxylamine hydrochloride aqueous solution, heating to boiling, cooling, and solid TKX-50 separation from the solution.
The claims collectively cover an integrated one-pot process for producing bis 5,5′-tetrazole-1,1′-dihydroxide and its ammonium and hydroxylammonium derivatives under controlled temperature and reagent addition conditions, eliminating toxic and hazardous intermediates and solvents.
Stated Advantages
Eliminates usage of toxic and hazardous chemicals such as chlorine and hydrogen chloride gases.
Avoids use of highly flammable solvents like diethyl ether.
Simplifies the preparation process to a safer, one-pot protocol suitable for larger scale synthesis.
Reduces safety risks by controlling reaction temperature and reagent addition, avoiding highly sensitive intermediates.
Documented Applications
Replacement energetic materials for RDX in civil and military applications.
Interested in licensing this patent?