Palladium Catalyst in the HBIW Hydrodebenzylation Reaction. Deactivation and Spent Catalyst Regeneration Procedure

Abstract

Abstract:The BAM-Fallhammer is a mechanical device to test the impact sensitivity of explosives and to determine a sensitiveness level. By its construction it transforms potential energy into kinetic energy of an impacting hammer, then hitting the sample. Ideally the entire potential energy is available at the moment of impact and the supporting base is infinitely rigid. By this study we want to quantify how much a real Fallhammer deviates from the ideal concept, and what the differences between different Fallhammers in different laboratories are. This information has never been collected in a consistent way. The aim of the authors is to develop guidance on the mechanical properties of the Fallhammer, which can be used for different purposes such as internal quality control, validation of the correct functioning of the Fallhammer, preparation of Round-Robin tests and similar. An established and verified mechanical status of a Fallhammer would greatly improve the quality and comparability of results and Round-Robin tests on the impact sensitivity of explosives.

Role of the Bromide on the Hydrodebenzylation of 2,4,6,8,10,12‐Hexabenzyl‐2,4,6,8,10,12‐hexaazaisowurtzitane (HBIW)

“…The intermediate after debenzylation should be acetylated by Ac 2 O to avoid the ring opening of the isowurtzitane, and TADBIW can be obtained after the HBIW undergo four cycles of debenzylation‐acetylation. As a result, the hydrogenolysis of HBIW required extremely efficient catalysts to accelerate the cycles of debenzylation‐acetylation, which can reduce the negative effect of the fragile stability of the intermediates [27–29] …”

“…As a result, the hydrogenolysis of HBIW required extremely efficient catalysts to accelerate the cycles of debenzylation-acetylation, which can reduce the negative effect of the fragile stability of the intermediates. [27][28][29] The catalytic performance of the as-obtained Pd/g-C 3 N 4 NS on the hydrogenolysis of HBIW was examined. The hydrogenolysis of HBIW was conducted under atomspheric pressure and the conversion of HBIW was monitored by UPLC (Fig- ure S2).…”

Ultrasmall Pd Nanoparticles Supported on TiO2 for Catalytic Debenzylation via Hydrogenative C–N Bond Cleavage

“…The hydrogenolysis of HBIW was implemented in a 150 mL reaction vessel via magnetic stirrer and heated with a water bath as reported. ,,, The parameters were 500–600 rpm and 0.40 MPa. Typically, 2.5 mL of DMF, 1.5 mL of Ac 2 O, 0.02 mL of PhBr, 1.0 g of HBIW, and 0.05 g of catalysts were placed into the reactor.…”

“…The cleavage of the C–N bond via hydrogenolysis is one of the most frequently used deprotecting classifications for amino functionalities with benzyl groups in the fields of fine chemistry as well as pharmaceuticals and the military. − The hydrogenolysis reactions are commonly based on heterogeneous Pd-based catalysts. However, some significant problems for practical application often appear, such as low yields for some special debenzylation reactions, , a high precious metal loading and usage amount, and poor stability. − Varieties of Pd particle catalysts have to be explored in order to improve the cost efficiency of debenzylation processes, such as Pd particles supported on different carbons, , Pd/Al 2 O 3 , Pd/In 2 O 3 , Pd/SiO 2 , − Pd/DOWEX, and others. ,− Recently, Ananikov et al reported that Vulcan XC-72 carbon carried 1 wt % Pd particles disclosed with a high turnover number (TON) up to 5000 with a low usage amount of only 0.02–0.3 mol % of Pd for the transfer hydrodebenzylation system with HCO 2 H as the reductant. From the viewpoint of practical applications, development of more cost-effective Pd catalysts is still an attractive topic to debenzylation.…”

Research Progress and Key Issues of Hydrodebenzylation of Hexabenzylhexaazaisowurtzitane (HBIW) in the Synthesis of High Energy Density Material Hexanitrohexaazaisowurtzitane (HNIW)

“…Comparisons of the physicochemical properties and explosion characteristics of the II-IVgeneration explosives[1,10].…”