609-13-2Relevant academic research and scientific papers
Solvent-free preparation of α,α-dichloroketones with sulfuryl chloride
Tu, Dewei,Luo, Juan,Jiang, Wengao,Tang, Qiang
supporting information, (2021/09/15)
An efficient and facile method is reported for the synthesis of a series of α,α-dichloroketones. The direct dichlorination of methyl ketones and 1,3-dicarbonyls using an excess amount of sulfuryl chloride affords the corresponding gem-dichloro compounds in moderate to excellent yields. Moreover, the protocol features high yields, broad substrate scope, and simple reaction conditions without using any catalysts and solvents.
Lipophilic indole mediated chemoselective α-monobromination of 1,3-dicarbonyl compounds
Wong, Jonathan,Ke, Zhihai,Yeung, Ying-Yeung
, (2020/03/04)
A mild and efficient mono-selective bromination of 1,3-dicarbonyl compounds has been developed using lipophilic indole catalysts. Inexpensive and commercially available N-bromosuccinimide (NBS) was used as the brominating reagent. The selectivity was further enhanced when using stoichiometric amount of 3-bromoindole species. Mechanistic studies reveal that the indole catalyst has dual functions in the mono-bromination process.
Flash preparation of carbenoids: A different performance of cyanogen bromide
Hedayati, Mohammad Jalilzadeh,Pesyan, Nader Noroozi
, p. 2081 - 2089 (2015/04/22)
Cyanogen halides are known substances for the cyanating reaction. There are a few evidences for bromination reaction too. On the other hand carbenes are known as very important substances due to their remarkable reactions. Unfortunately carbenes at room temperature are very unstable and there is not a simple method for preparation of them. In most cases the isolation is not possible. We have reported a new reliable and fast preparation method of almost stable carbenoids. The mechanism of the formation has been discussed.
Oxidative bromination of ketones using ammonium bromide and oxone
MacHarla, Arun Kumar,Chozhiyath Nappunni, Rohitha,Marri, Mahender Reddy,Peraka, Swamy,Nama, Narender
supporting information; experimental part, p. 191 - 195 (2012/01/17)
A highly efficient, environmentally safe and economic method for selective α-monobromination of aralkyl, cyclic, acyclic, 1,3-diketones and β-keto esters and α,α-dibromination of 1,3-diketones and β-keto esters without catalyst is reported using ammonium bromide as a bromine source and oxone as an oxidant. The reaction proceeds at ambient temperature and yields range from moderate to excellent. Bromination of unsymmetrical ketones takes place at the less substituted α-position predominantly. Aromatisation of tetralones is also carried out with this reagent system.
One-pot new barbituric acid derivatives derived from the reaction of barbituric acids with BrCN and ketones
Hosseini, Yaser,Rastgar, Saeed,Zerrin Heren,Orhan Büyükgüng?r,Pesyan, Nader Noroozi
experimental part, p. 309 - 318 (2011/11/06)
Reaction of cyclic β-dicarbonyl compounds such as pyrimidine-(1 H,3H,5H)-2,4,6-trione (BA), 1,3-dimethyl pyrimidine-(1 H,3H,5H)-2,4,6-trione (DMBA) and 2-thioxo-pyrimidine-(1 H,3H,5H)-4,6-dione (TBA) with cyanogen bromide in acetone and 2-butanone in the presence of triethylamine afforded a new class of stable heterocyclic spiro[furo[2,3-d]pyrimidine-6,5′-pyrimidine]2, 2′,4,4′,6′(3H,3′H,5H)-penta-ones (dimeric forms of barbiturate) at 0 °C and ambient temperature. Structure elucidation was carried out by X-ray crystallographic, 1H NMR, 13C NMR, two dimensional NMR, FT-IR spectra, mass spectrometry and elemental analysis. The mechanism of product formation is discussed. The reaction of DMBA with cyanogen bromide in the presence of triethylamine also afforded trimeric form of barbiturate of uracil derivatives in good yield. The reaction of selected acyclic β-dicarbonyl compounds with cyanogen bromide in the presence of triethylamine in acetone and/or diethyl ether has also been investigated under the same condition. Diethyl malonate and ethyl cyanoacetate brominated and also ethyl acetocetate both bro-minated and cyanated on active methylene via cyanogen bromide.
Photochemical α-bromination of ketones using N-bromosuccinimide: a simple, mild and efficient method
Arbuj, Sudhir S.,Waghmode, Suresh B.,Ramaswamy
, p. 1411 - 1415 (2007/10/03)
Aromatic and aliphatic carbonyl compounds undergo facile bromination with N-bromosuccinimide under UV-vis irradiation to give the corresponding α-brominated ketones in good yields, at low temperatures (30 °C), without any catalyst, catalyst support or radical initiator and within a short time.
α-bromination of 1,3-dicarbonyl compounds using Dess-Martin periodinane (DMP) and tetraethylammonium bromide (TEAB)
Salgaonkar, Paresh D.,Shukla, Vidyanand G.,Akamanchi, Krishnacharya G.
, p. 275 - 280 (2007/10/03)
A mild and expeditious method for α-bromination of 1,3-dicarbonyl compounds using Dess-Martin periodinane and tetraethylammonium bromide is described. Copyright Taylor & Francis Group, LLC.
Ionic liquid promoted selective debromination of α-bromoketones under microwave irradiation
Ranu, Brindaban C.,Chattopadhyay, Kalicharan,Jana, Ranjan
, p. 155 - 159 (2007/10/03)
The debromination of α-bromoketones with an easily accessible ionic liquid, 1-methyl-3-pentylimidazolium tetrafluoroborate, [pmIm]BF4 under microwave irradiation has been investigated. By controlling the reaction time gem-α-dibromoketones are selectively debrominated to either monobromo or debromoketones. The α-monobromo- and α-monoiodoketones are dehalogenated while the corresponding chloroketones remain inert. The activated vic-bromoacetates are converted to the corresponding (E)-alkenes by the same procedure. These reactions do not require any organic solvent, any metal or any conventional reducing agent. The ionic liquid works here as catalyst as well as reaction medium and is recycled without any appreciable loss of its catalytic efficiency.
A mild and environmentally acceptable synthetic protocol for chemoselective α-bromination of β-keto esters and 1,3-diketones
Khan, Abu T.,Goswami, Papori,Choudhury, Lokman H.
, p. 2751 - 2754 (2007/10/03)
A wide variety of unsubstituted β-keto esters can be brominated chemoselectively to the corresponding α-monobromo-β-keto esters by using a combination of vanadium pentoxide, hydrogen peroxide and ammonium bromide in a biphasic system, dichloromethane-wate
Nonselective bromination-selective debromination strategy: Selective bromination of unsymmetrical ketones on singly activated carbon against doubly activated carbon
Choi, Han Young,Chi, Dae Yoon
, p. 411 - 414 (2007/10/03)
(Matrix presented) We have found a new synthetic method for the preparation of the α-bromoketones that are brominated in the less activated terminal position of unsymmetrical ketones. Brominations in short reaction times (kinetically controlled) provided internally brominated compounds as a major product. However, brominations in longer reaction times (thermodynamically controlled) gave more of the terminally brominated compound through the reversible reaction by Br2 and produced hydrogen bromide. Several brominated compounds at the terminal position were successfully prepared through the new synthetic route.
