A facile route to amino-azines

Abstract

Aminoazines are interesting intermediates in the preparation of 1,2,4-triazoles 1,2 and imidazoles. 3 1-Amino-1,4-diphenyl-2,3diazabutadiene (3) was first made in 1914 by Stollé, 4 from the reaction of the corresponding chloro-azine with ammonia. 3,5-Diphenyltriazole and diphenyltetrazine were formed as by-products. In 1971, Taylor and co-workers repeated this reaction and obtained the amino-azine (3) in 38% yield. 1,4-Diamino-1,4diphenyl-2,3-diazabutadiene, 3,5-diphenyltriazole, and diphenyltetrazine were also obtained as by-products. 1 Another route to amino-azine (3) was reported by van der Burg, 5 who claimed that the reaction of amidrazones with benzaldehyde would give their N 1 -benzylidene derivatives, which are amino-azines. However, conflicting reports have appeared in the literature concerning the products formed in such reactions.Taylor 6 and Case 7 came to the same conclusion as van der Berg, and stated that the reaction of amidrazones with monocarbonyl compounds would give their aryl or alkylidene derivatives. On the other hand, Case reported the formation of 1,2,4-triazolines rather than amino-azines. [8][9][10] Zelenin claimed the formation of both amino-azines and triazolines. 11

Synthesis and Functionalization of 5‐Substituted Tetrazoles

“…As a result of this modification, the reaction times were shortened, but larger amounts of sodium azide and zinc salts were used than in the original procedure. [67] Three microwave-assisted methods based on Sharpless' work [65] have been published since 2005. Specific 5-STs were prepared in yields of 75-91 % after 20 minutes under microwave heating to 185°C.…”

β‐Cyclodextrin Monosulphonic Acid Promoted Multicomponent Synthesis of 1,8‐Dioxodecahydroacridines in Water

“…The most commonly used protocol for the synthesis of 1,8dioxodecahydroacridines involves reactions between aromatic aldehydes, dimedone and nitrogen sources such as ammonium acetate, [14] hydroxylamines, [15] aniline, [16] ammonium bicarbonate [17] and ammonium hydroxide. [18] The previously reported catalysts for the synthesis of 1,8-dioxodecahydroacridine derivatives are DCH (1,3-dichloro-5,5-dimethylhydantoin), [19] amberlyst-15, [20] SO 4 2À /ZrO 2 , [21] nano-Fe 3 O 4 @SiO 2 -SO 3 H, [22] Brønsted acidic imidazolium salts containing perfluoroalkyl tails, [23] ionic liquids, [24] CAN, [25] MNPsÀ N-propyl-benzoguanamine-SO 3 H, [26] Fe 3 O 4 @SiO 2 -MoO 3 H, [27] silica iodide, [28] KH 2 PO 4, [29] FSGÀ Hf (NPf 2 ) 4 , [30] MCM-41-SO 3 H, [31] oxalic acid, [32] SiO 2 -ZnCl 2, [33] TPA NPs/ PAA, [34] magnetic titania-SO 3 H, [35] Fe 3 O 4 @DA-SO 3 H, [36] nano-ferrite [37] and n-ZrSA. [38] Despite the various reports for the synthesis of 1,8dioxodecahydroacridine derivatives, many of them are having disadvantages such as use of expensive catalysts, higher temperature, longer reaction time, tedious procedure, lower yield and use of toxic chemicals.…”

Nano‐TiO2 as an Efficient Catalyst for Tandem Knoevenagel–Michael‐Cyclocondensation Reaction of Dimedone with Aromatic Aldehydes and Ammonium Acetate or Aromatic Amines under Solvent‐free Conditions

“…21 Several methods have been introduced for the preparation of 1,8-dioxo-deca-hydroacridine derivatives. [22][23][24][25][26][27] However, some of them suffer from the drawbacks such as the use of toxic metals, the use of volatile organic solvents, high cost and low yields. Solvent-free reactions have been demonstrated to be as an efficient technique for various organic transformations instead of using harmful organic solvents.…”