Some Reactions of 3,6-Bis(4-amino-1,2,5-oxadiazol-3-yl)-1,4,2,5-dioxadiazine

Shaposhnikov, S. D.; Романова, Т. В.; Spiridonova, N. P.; Мельникова, С. Ф.; Целинский, И. В.

doi:10.1023/b:rujo.0000044554.65764.fa

Cited by 24 publications

(11 citation statements)

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“…Historically, the 1,4,2,5-dioxadiazines have been little studied. 56 However, relevant to the furoxan cycloreversion discussed earlier, flash vacuum thermolysis of 3,6-diphenyl-1,4,2,5-dioxadiazine has been shown to involve cleavage of the 1-2 (O-N) and 3-4 (C-O) bonds to give benzonitrile and other products, 57 rather than nitrile oxides, in keeping with the very high activation energies for thermal cycloreversion determined here (Fig. 7).…”

Section: Dimerisation To Furoxanssupporting

confidence: 87%

Dimerisation of nitrile oxides: a quantum-chemical study

Pasinszki

Hajgató

Havasi

et al. 2009

Phys. Chem. Chem. Phys.

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The [3 + 2] and [3 + 3] cyclodimerisation processes of small nitrile oxides, XCNO (X = F, Cl, Br, CN, CH(3)) are investigated by ab initio coupled cluster theory at the CCSD, CCSD(T) and MR-AQCC levels for the first time. The favoured dimerisation process is a multi-step reaction to furoxans (1,2,5-oxadiazole-2-oxides) involving dinitrosoalkene-like intermediates with diradical character. The rate determining step for all but the F-species is the first, corresponding to the C-C bond formation. The kinetic energy barrier depends on the nature of the substituent X, generally increasing with decreasing electronegativity and increasing pi-donor ability of the substituent: F (DeltaG(298) = 0 kJ mol(-1)) < Cl (72) < Br (90) < CH(3) (104) < CN (114) (MR-AQCC(2,2)//UB3LYP/cc-pVTZ). Following initial C-C bond formation, three possible dinitrosoethylene diradical pathways are explored. Two of them are new, and one of them is a low-energy three-step path with implications for cycloreversion, tautomerism and detection of dinitrosoethylene intermediates. Alternative one-step, concerted [3 + 2] and [3 + 3] cyclodimerisation processes leading to 1,2,4-oxadiazole-4-oxides and 1,4,2,5-dioxadiazines have kinetic energy barriers around 100-240 kJ mol(-1) (CCSD//B3LYP), some 1.6 to 2.5 times higher than those leading to furoxans, supporting the experimental observations of furoxan formation as nitrile oxide loss channels during storage, trapping/re-vaporisation and reactions of nitrile oxides. Potential polymerisation initiation processes for NCCNO, involving the 1,2-dipolar NC substituent are also explored.

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Section: Dimerisation To Furoxanssupporting

confidence: 87%

Dimerisation of nitrile oxides: a quantum-chemical study

Pasinszki

Hajgató

Havasi

et al. 2009

Phys. Chem. Chem. Phys.

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“…One final concern over the approach to 2 outlined in Scheme 1 is in the condensation of benzocyclobutylamine 5 with imidoyl chloride 6. As noted elsewhere, 22,23 nitrile oxide 12 formed from treatment of imidoyl chloride 6 with base can homodimerize to form the symmetrical dioxadiazene 13 and/ or its isomeric oxadiazole oxide 15, depending on the reaction conditions used (Scheme 3). As expected, these species are highly energetic, and their corresponding oxidation products (14 and 16) are known explosives.…”

Section: ■ Results and Discussionmentioning

confidence: 91%

“…As expected, these species are highly energetic, and their corresponding oxidation products (14 and 16) are known explosives. 22,23 While the outcome of the condensation of 5 and 6 seems to primarily result in the formation of 7, we have not attempted to prove that neither 13 nor 15 is present in the isolated product from this reaction because synthesis of the corresponding markers and their handling is considered high-risk. Therefore, 7 as well as 8 could technically contain these corresponding impurities, depending on the reaction parameters used.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…One final concern over the approach to 2 outlined in Scheme is in the condensation of benzocyclobutylamine 5 with imidoyl chloride 6 . As noted elsewhere, , nitrile oxide 12 formed from treatment of imidoyl chloride 6 with base can homodimerize to form the symmetrical dioxadiazene 13 and/or its isomeric oxadiazole oxide 15 , depending on the reaction conditions used (Scheme ). As expected, these species are highly energetic, and their corresponding oxidation products ( 14 and 16 ) are known explosives. , While the outcome of the condensation of 5 and 6 seems to primarily result in the formation of 7 , we have not attempted to prove that neither 13 nor 15 is present in the isolated product from this reaction because synthesis of the corresponding markers and their handling is considered high-risk.…”

Section: Resultsmentioning

confidence: 99%

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Process Safety Considerations for the Supply of a High-Energy Oxadiazole IDO1-Selective Inhibitor

Martinot

Ardolino

Chen

et al. 2019

Org. Process Res. Dev.

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The development of a stereospecific synthesis of a IDO1-selective inhibitor is described. The synthetic strategy toward enabling early discovery efforts along with additional findings pertaining to process safety that limited scalability are outlined. A convergent approach that supported the synthesis of material suitable for early preclinical and/or good laboratory practice toxicology studies and avoided the formation of key high-energy intermediates is summarized.

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“…Also nitrous acid can be recovered by formation of nitrile oxides 8, which dimerize to form 1,2,5oxadiazole 2-oxides 9, 15 and/or 1,4,2,5-dioxadiazines 10. [39][40][41] Hence, nitrous acid can participate in decomposition of ANMs both during the reaction and during isolation. We did not determine the actual yields of the by-products because optimizations were intended only to increase the ANM outputs and to block all decomposition processes.…”

Section: Paper Synthesismentioning

confidence: 99%

Preparation of Ring-Methoxylated Arylnitromethanes by the Victor Meyer Reaction

Кислый¹,

Maksimenko²,

Buikin³

et al. 2022

Synthesis

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Easily accessible and stable ring-methoxylated benzyl chlorides react with AgNO2 to give mixtures of the corresponding arylnitromethanes and nitrite esters. A modified approach for the isolation of arylnitromethanes is described, which represents a valuable improvement of the established Victor Meyer reaction. The isolation technique, which involves reaction of the nitrite ester with urea in methanol, allows the desired arylnitromethanes to be isolated, without loss, in 29–75% yields, and generates the corresponding recyclable benzyl alcohols. Unexpectedly, ring-methoxylated benzyl iodides cannot be used because they are not sufficiently stable and produce tars under the developed reaction conditions.

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Some Reactions of 3,6-Bis(4-amino-1,2,5-oxadiazol-3-yl)-1,4,2,5-dioxadiazine

Cited by 24 publications

References 1 publication

Dimerisation of nitrile oxides: a quantum-chemical study

Dimerisation of nitrile oxides: a quantum-chemical study

Process Safety Considerations for the Supply of a High-Energy Oxadiazole IDO1-Selective Inhibitor

Preparation of Ring-Methoxylated Arylnitromethanes by the Victor Meyer Reaction

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