Heterocycles from Nitrile Imines. Part 1. 1,2,3,4-Tetrahydro-1,2,4,5-Tetrazines

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

“…The electron impact (EI) mass spectra (Table 1) The 13 C NMR spectra of products 4a-g exhibit a signal at 70-90 ppm attributed to C6 (quaternary or spiro carbon). This is similar to reported values of quaternary or spiro carbons flanked by tow nitrogens in six-membered heterocycles (2)(3)(4)9). This provides strong evidence in support of structures 4a-g rather than acyclic structures.…”

“…Similar intramolecular cyclization, following the initial 1,3-nucleophilic addition step of suitably functionalized nucleophilic substrates onto nitrilimines was reported by El-Abadelah et al (2,4) (Scheme 1).…”

“…The reactive 1,3-dipole nitrilimines are reported to react differently with hydrazones: Their reaction with methyl hydrazones of aliphatic aldehydes and ketones provides the 1,2,3,4-tetrahydro-stetrazines (2,3). On the other hand, methyl hydrazones of aromatic aldehydes give a mixture of cyclic and acyclic tetrazines (4).…”

Synthesis of nitrogen-containing dispiroheterocycles using nitrilimines (II)

“…The hydrazonoyl halides 1a-j were prepared by a modified literature procedure [6][7][8][9][10][11][12][13][14] and the nitrilimines 2 were generated in situ from 1 by reaction with triethylamine (Et 3 N). The non-isolatable nitrilimines 2 reacted readily with 1,4--cyclohexanedione dioxime 3 affording the corresponding 1,2,4,9,10,12-hexaazadispiro [4.2.4.2]tetradeca-2,10-dienes 5a-j (Scheme 1).…”

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).…”