Microwave irradiation assisted facile synthesis of new imidazole, pyrazine, and benzodiazocine derivatives using diaminomaleonitrile

Abstract

Utilizing domestic microwave oven reactions of diaminomaleonitrile with various selected reagents, novel heterocycles such as dicyanopyrazine, 4,5-dicyanoimidazole as well as dicyanobenzodiazocine derivatives were prepared.

Microwave-Assisted Synthesis of Bioactive Six-Membered Heterocycles and Their Fused Analogues

“…Moreover, Alfonsi et al [233] have reported the synthesis of pyrazines derivatives and other series of N-heterocycles 250, 251 by tandem imination/annulation of γ-and δ-ketoalkynes 249. The reaction was achieved by the intramolecular cyclization of 2-acetyl-1-propargylpyrroles in the presence of ammonia Original synthetic heterocycles, such as substituted dicyanopyrazines 247, 248, have been synthesized using a domestic MW oven [232]. The reaction proceeded by a cyclocondensation of diaminomalonitrile with ketones (e.g., acenaphthenequinone, 245) or an ester 246 in the presence of triethylamine in ethanol (Scheme 52), and the expected products were obtained with good to excellent yields.…”

“…Moreover, they are versatile synthetic intermediates [225], and many functionalized pyrazines possess pharmacological activities, such as antiviral [226,227] (242, 243), ATR kinase inhibitor [228] (244), antitumor [229], vascular endothelial growth factor inhibitory activity [230], or as epithelial sodium channel blockers [231] (Figure 15). Original synthetic heterocycles, such as substituted dicyanopyrazines 247, 248, have been synthesized using a domestic MW oven [232]. The reaction proceeded by a cyclocondensation of diaminomalonitrile with ketones (e.g., acenaphthenequinone, 245) or an ester 246 in the presence of triethylamine in ethanol (Scheme 52), and the expected products were obtained with good to excellent yields.…”

Europium Triflate–Catalyzed One‐Pot Synthesis of 2,4,5‐Trisubstituted‐1H‐imidazoles via a Three‐component Condensation

“…Methods of synthesis of imidazoles include a four-component condensation using Wang's resin in refluxing acetic acid; [5] condensation of 1,2-diketones, aldehydes, primary amines, and ammonium acetate in phosphoric acid [6] and in acetic acid; [7] using an organocatalyst in acetic acid, [8] as well as in H 2 SO 4 [9] and dimethyl sulfoxide (DMSO); [10] condensation of benzoin, aldehydes, and ammonium acetate in a variety of catalysts, such as molecular iodine, [11] [Hbim]BF 4 , [12] microwave (MW)/silica gel/NaHSO 4 , [13] MW/AcOH, [14] MW/Et 3 N, [15] and MW/ Al 2 O 3 /NH 4 OAC; [16] and condensation of two different isocyanides in the presence of Cu 2 O. [17] However, many of these procedures suffer from disadvantages, such as harsh reaction conditions, prolonged reaction times, high reaction temperature, and low isolation yields, and the catalysts cannot be recovered and reused in most of the existing methods.…”

Condensation of 1‐(Dicyanomethylene)acenaphthene‐2‐one with Aromatic Diamines

“…The synthesized compound was obtained from the reaction of equivalent amounts of 1-methyl-3,5bis[(E)-4-chlorophenylmethylidene]tetrahydro-4(1H)pyridinone with 1 and sarcosine. 11 We have spent a long time on the synthesis of new heterocycles via condensation reactions 1,12 and/or donor-acceptor interaction. [13][14][15][16] Accordingly and in this paper, we have prompted to utilize 1-(dicyanomethylene)acenaphthen-2-one (1) in the synthesis of new heterocyclic compounds which might show prospective biological activities.…”

“…Condensation of 1 with 5,6-diamino-pyrimidine-2,4diol hemisulphate (11) led to the formation of acenaphtho-[1,2-g]pteridine-9,11-diol (12). Compound 12 exhibited IR absorptions at n = 3512 and 1645 cm -1 which were ascribable to OH and C=N, respectively.…”