Selenium‐Containing Heterocycles from Isoselenocyanates: Synthesis of 1H‐5‐Selena‐1,3,6‐triazaaceanthrylene Derivatives

Abstract

The reaction of aryl isoselenocyanates 8 with methyl 3-amino-4-chloro-1-ethylpyrrolo[3,2-c]quinoline-2-carboxylate (6) in boiling pyridine leads to tetracyclic selenaheterocycles of type 9 in high yield (Scheme 3). A reaction mechanism via an intermediate selenoureido derivative A and cyclization via nucleophilic substitution of Cl by Se is proposed (Schemes 3 and 5). The reaction of 6 with 4-bromophenyl isothiocyanate yields the analogous thiaheterocycle 12 (Scheme 4). The molecular structures of 9c and 12 have been established by X-ray crystallography. (Schemes 3 and 5). The reaction of 6 with (4-bromophenyl) isothiocyanate yields the analogous thiaheterocycle 12 (Scheme 4).The molecular structures of 9c and 12 have been established by X-ray crystallography.3

Selenium‐Containing Heterocycles From Isoselenocyanates: Synthesis of1,3‐Selenazolidine and Perhydro‐1,3‐selenazine Derivatives

“…To the best of our knowledge, only a few papers describe the preparation of nonfused selenazoles from an isoselenocyanate [45][46][47][48] and, surprisingly, only one selenazole derivative prepared from a primary amine has been described. [49] We have recently shown that aryl isoselenocyanates 1 are convenient precursors for the introduction of selenium into five-and six-membered selenaheterocycles of types 3 [50] and 5, [51] respectively (Scheme 1). The aromatic starting materials 2 and 4 for these reactions each bore a primary amino group and a halogen atom.…”

“…As a continuation of our studies in isoselenocyanate chemistry [50][51][52][53][54][55][56][57] we investigated the synthesis of five-and six-membered Se/N-heterocycles: 1,3-selenazoles and 1,3-Scheme 2. www.eurjoc.org selenazines. In this paper we report on reactions of aryl and alkyl isoselenocyanates 1 with the ω-halogeno alkylamines 9 and 10.…”

Selenium-Containing Heterocycles From Isoselenocyanates: Synthesis of Ethyl 4-oxo-2-amino-4,5-dihydroselenophene-3-carboxylates

“…Compounds of this type, including 4-oxofurans, are known as novel antiallergic agents [6]. 2 As a part of our program aimed at the development of simple procedures for the preparation of selenium-containing heterocycles [7][8][9][10][11][12][13][14], we have recently reported on the utility of isoselenocyanates for the synthesis of selenazetidines [15], selenazolidines [16,17], selenazines [16,18], selenadiazines [19], selenazepines [20], selenorhodanines [21], and triazoleselones [22]. As a continuation of this work, we report here on a novel and efficient synthesis of selenophene derivatives.…”

Thia- and selenaheterocycles by a four-component reaction using elemental sulfur and selenium

“…[18]), we have prepared a series of selenium-containing four- [19,20], five- [21][22][23][24][25][26], six- [27,28], seven- [29], and eightmembered [30] heterocycles. In some cases, the reactions were carried out analogously to those with isothiocyanates, and the reactivity of the two heterocumulenes was observed to be very similar.…”