1.3- Diazocines synthesis

Dibenzodiazocine, 6,12-diamino-synthesis, 7, 683 Dibenzodiazocine, 6,12-dioxo-synthesis, 7, 683 Dibenzo[c,g][ 1,2]diazocine synthesis, 7, 672 Dibenzo[6,/][ 1,4]diazocine synthesis, 7, 675... 

Since 1995, a few examples of the 1,4-diazocine synthesis by condensation reactions with the formation of two C-N bonds have been described. 

In a novel 1,4-diazocine synthesis, diacetylene was condensed with ED and 1,2-propylenediamine to afford diazocines 123 (63DOK1353). Nakamura and Kamila ran a Mannich condensation with benzoylpyrrole 124 and... 

In a novel 1,4-diazocine synthesis, diacetylene was condensed with ED and... 

Aryl-substituted pyridines and pyrimidines have been prepared by 2 - - 2-cycloadditions of alkynyl-substituted pyridines and pyrimidines with electron-rich dienes." The reactions proceed by formation of a bridged cycloadduct and subsequent thermal extrusion of ethylene. The pyridine moiety plays a crucial role for the success of the reaction. 2-Benzoylbenzoyl azides undergo facile cycUzation under acidic conditions to give substituted dibenzo[ / [l,5]-diazocines in good yields. The mechanism of the diazocine synthesis was assumed to proceed by an unprecedented intermolecular 2 - - 2-cyclization. 

Diazocine, 3,8-dialkyloctahydro-synthesis, 7, 670 Diazocine, 3,8-diaryloctahydro-synthesis, 7, 670 Diazocine, 1,4-dihydro-aromaticity, 7, 677 Diazocine, 5,6-dihydro-synthesis, 7, 673... 

Dibenzo[b,/][l,5]diazocine, tetrahydro-conformation, 7, 704 Dibenzo[b,/][l,4]diazocinediones synthesis, 7, 675 Dibenzodioxin, 2,7-dichloro-toxicity, 3, 992 Dibenzodioxin, hexachloro-toxicity, 3, 992 Dibenzodioxin, octachloro-toxicity, 3, 992... 

Reduction should result in l,2-dihydro-l,2-diazocine (2) which formally contains a cyclic, conj ugatcd 10 7r-electron system and potentially possesses aromatic character. To date, however, only the synthesis of a dibenzo derivative has been described (see Section 1.2.1.3.). 

An important method for the synthesis of 1,3-diazocines consists of the reaction of pyrimidines 1 with ynamines to give [2 + 2] cycloadducts, which rearrange to the eight-membered-ring compounds 2 by valence tautomerization.2-3... 

Dichlorodibenzo[/>,/][l,5]diazocine (4, vide supra) can be used for the synthesis of several other derivatives by substitution reactions. 

A one-pot synthesis of 3-methyl-5-aryl-4//-pyrrolo[2,3-<7]isoxazoles was performed in high yields by Sharpless epoxidation of 4-amino-3-methyl-5-styrylisoxazoles <06TL4957>. 1,2,4,5-Tetrazines were condensed with isoxazolylcyclobutanones in methanolic KOH to give conformationally restricted 6-isoxazol-5-yl-6,7-dihydro-5//-[l,2]diazocin-4-ones <06JOC2480>. 

Inductive effects can have very pronounced effects on the reactivity of amides and similar substrates towards nitrolysis. Chemists at the Naval Air Warfare Center (NAWC) have reported an extreme case encountered during the synthesis of the energetic 1,5-diazocine known as HNFX (86). A key step in this synthesis involves a very difficult nitrolysis of the electron deficient N-nosyl (4-nitrobenzenesulfonyl) bonds of (85). Nitrolysis with strong mixed acid requires a temperature of 70 °C for 6 weeks to achieve a yield of 16 %. The same reaction with nitric acid-triflic acid requires a temperature of 55 °C for 40 hours to achieve a 65 % yield of HNFX. The same chemists reported a similar case of N-nosyl bond nitrolysis which needed a nitrating agent composed of nitric acid-triflic acid-antimony pentafluoride. ... 

Since the most common group of 1,3-diazocines is related to cyclic urea 104 (called, for example, perhydro-l,3-diazocine-2-one or N,N -pentamethyleneurea), a separate section is devoted to the synthesis, chemistry, and applications of 104, substituted 104, and related molecules such as thiourea 105, guanidines 106, and carbodiimide 107. 

Theodore Axenrod Xiao-Pei Guan Sun, Jianguang Qi Lida, Robert Chapman, Richard D.Gilardi Synthesis of 3,3-Bis(difluoramino)octahydro-l,5,7,7-l,5-diazocine(TNFX), a Diversified Energetic Heterocycle, Tetrahedron Letters, 42(2001) 2621-2623. 

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