7661-27-0Relevant academic research and scientific papers
Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]tri-azolo[1,5-d][1,4]diazepine derivatives by [3+ + 2]-cyclo-addition/rearrangement reactions
Luan, Lin-bo,Song, Zi-jie,Li, Zhi-ming,Wang, Quan-rui
, p. 1826 - 1833 (2018/08/21)
Two new series of tricyclic heterocycles, namely 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepinium salts 10 and the related neutral, free bases 13 were synthesized from 4-acetoxy-1-acetyl-4-phenylazo-1,2,3,4-tetrahydroquinolines 8 and nitriles 9 in the presence of aluminium chloride by the [3+ + 2]-cycloaddition reaction of the in situ generated azocarbenium intermediates 14 followed by a ring-expansion rearrangement. In the rearrangement reaction, the phenyl substituent in the initially formed spiro-triazolium adducts 16 underwent a [1,2]-migration from C(3) to the electron-deficient N(2). This led to the ring expansion from 6-membered piperidine to 7-membered diazepine furnishing the tricyclic 1,2,4-triazole-fused 1,4-benzodiazepines.
Formation of acridones by ethylene extrusion in the reaction of arynes with β-lactams and dihydroquinolinones
Fang, Yuesi,Rogness, Donald C.,Larock, Richard C.,Shi, Feng
, p. 6262 - 6270 (2012/09/22)
N-Unsubstituted β-lactams react with a molecule of aryne by insertion into the amide bond to form a 2,3-dihydroquinolin-4-one, which subsequently reacts with another molecule of aryne to form an acridone by extrusion of a molecule of ethylene. 2,3-Dihydroquinolin-4-ones react under the same reaction conditions to afford identical results. This is the first example of ethylene extrusion in aryne chemistry.
Synthesis of 2,3-dihydro-4(1H)-quinolones and the corresponding 4(1H)-quinolones via low-temperature fries rearrangement of N-arylazetidin-2- ones
Lange, Jens,Bissember, Alex C.,Banwell, Martin G.,Cade, Ian A.
experimental part, p. 454 - 470 (2011/10/09)
N-Arylazetidin-2-ones of the general form 1, which are readily prepared by GoldbergBuchwald-type copper-catalyzed coupling of N-unsubstituted azetidin-2-ones with the relevant aryl halide or using Mitsunobu cyclization processes, undergo smooth Fries-rearrangement in triflic acid at 018°C to give the isomeric 2,3-dihydro-4(1H)-quinolones (2). Dehydrogenation of the latter compounds using 10% Pd on C in 1.0M aqueous sodium hydroxide/propan-2-ol mixtures at ca. 82°C provides the corresponding 4(1H)-quinolones (3).
Palladium-catalyzed intermolecular coupling of aryl halides and amides
Yin, Jingjun,Buchwald, Stephen L.
, p. 1101 - 1104 (2007/10/03)
The first general intermolecular C-N bond-forming reactions between aryl halides and amides were realized using a palladium catalyst with Xantphos as the ligand. Aryl triflates, carbamates, and sulfonamides are also viable substrates for the amidations, which proceed at 45-110 °C with 1-4 mol% of Pd catalyst in 66-99% yields and exhibit good functional group compatibility.
A Convenient Synthesis of Monocyclic β-Lactams by Means of Solid-Liquid Phase Transfer Reactions
Takahata, Hiroki,Ohnishi, Yoshinori,Takehara, Hiroyuki,Tsuritani, Kazuko,Yamazaki, Takao
, p. 1063 - 1068 (2007/10/02)
The intramolecular N-alkylation of β-bromopropionamides (1) under phase transfer conditions afforded monocyclic N-substituted β-lactams (2) in high yields.In a similar manner, cyclization by N1-C4 bond formation gave 4-benzoyl-2-azet
Formation of 2,3-Dihydro-4(1H)-quinolones and Related Compounds via Fries-type Acid-catalysed Rearrangement of 1-Arylazetidin-2-ones
Kano, Shinzo,Ebata, Tsutomu,Shibuya, Shiroshi
, p. 2105 - 2111 (2007/10/02)
A variety of 1-arylazetidin-2-ones were treated with trifluoroacetic acid under reflux, methanesulphonic acid at 100 deg C, or conc. sulphuric acid to give the corresponding 2,3-dihydro-4(1H)-quinolones via acyl migration and N-CO fission.In the case of 1-(3-substituted phenyl)azetidin-2-ones, two positional isomeric products, 5- and 7-substituted 2,3-dihydro-4(1H)-quinolones were obtained. 4-Methyl, 4-ethoxycarbonyl, and 4-piperidin-2-yl-1-arylazetidin-2-ones and their analogues were also converted into the corresponding 2-substituted 2,3-dihydro-4(1H)-quinolones under acidic conditions.The 3-substituted 1-phenylazetidin-2-ones (36) and (37) were converted into the furoquinoline systems (38) and (40), respectively, by application of this method.
