Heterocyclic Synthesis Using Nitrilimines: Part 3(1). Synthesis of Substituted 1,2,4,5-Tetrazines and 1,2,4,5-Tetraaza-2-Pentenes

Abstract

The reaction of nitrilimines 2a.b with hydrazones of aliphatic ketones 3 (RHNN=CR'R 2 ) led to the formation of the cyclocondensation products 1,2,4,5-tetrazines 4a-g when R = CH3, and to acyclic electrophilic addition products 5a-g when R = H, rather than the cyclocondensation tetrazines products 8.

Synthesis of nitrogen-containing dispiroheterocycles (1) using nitrilimines

“…C NMR spectra showed all the signals corresponding to the proposed structures, especially C-6 and C-9 (spiro carbons) were found to resonate at about 75-70 ppm. This is similar to reported values of spiro carbons flanked by two nitrogen atoms in sixmembered heterocycles, 14,22 which provide strong evidence in support of the structures 4a-k. The …”

“…Examples of these modes of reactions were recently reviewed by Ferwanah et al 13 for the reactions of hydrazones and oximes with nitrilimines and nitrile oxides. The synthesis of different spiroheterocycles I-III was recently reported using nitrilimines and cycloalkanone hydrazones or oximes [14][15][16][17] ( Figure 1). As part of our program aimed at developing new biologically active compounds, we report here the synthesis of the hitherto unknown dispiroheterocyclic compounds 4a-k from the reaction between different nitrilimines 2 and 1,4-cyclohexanedione methyl hydrazone 3.…”

Reactions of N-alkylhydrazones of aliphatic ketones

“…Застосування для побудови тетрагідротетра-зинової системи 114 знайшла взаємодія гідразо-нів 112 із гідразоноїлхлоридами 113 [66,67] (схе-ма 39).…”

Six‐Membered Heterocycles: Triazines, Tetrazines and Other Polyaza Systems

“…Deliberate oxidation of 364 has been accomplished by treatment with ferric chloride to provide tetrazine 365 [762] (Scheme 20.107). New 1,2,4,5-tetrazines derivatives has been synthesized from substituted nitrilimines and different hydrazines [763][764][765] or hydrazones [765,766].…”