- High-yielding aqueous synthesis of chloroacetophenones and aroyl chlorohydrins
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The use of large amounts of volatile organic solvents in industrial chemical processes contributes to widespread environmental pollution. To help solve this problem, water and a phase transfer catalyst were used to replace organic solvents in the transformations of bromoacetophenones into chloroacetophenones and aroyl epoxides into aroyl chlorohydrins. The reactions were promoted by sulfonyl chlorides and gave quantitative or close to quantitative yields. Notably, chromatographic purification, which is laborious and consumes large amounts of organic solvents, was not needed. These two processes have opened a green and cost-effective channel to prepare the chemical intermediates chloroacetophenones and aroyl chlorohydrins. The reaction mechanisms are discussed based on control experiments.
- Zhang, Xixi,Liu, Lei,Li, Chunbao
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p. 25339 - 25345
(2016/03/22)
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- Target-oriented synthesis: Miscellaneous synthetic routes to access 1,4-enediones through the coupling of 1,3-dicarbonyl compounds with multiform substrates
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Target-oriented synthetic protocol was presented for the synthesis of 1,4-enediones. The approach can efficiently construct 1,4-enediones through different reaction pathways from multiform substrates α-halo aromatic ketones, 2-hydroxy-aromatic ketones and methyl carbinols. In this reaction, CuI was found to be the most efficient catalyst. Multiform substrates were also found to perform well to afford the products in a one-pot fashion.
- Zhu, Yan-Ping,Cai, Qun,Gao, Qing-He,Jia, Feng-Cheng,Liu, Mei-Cai,Gao, Meng,Wu, An-Xin
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supporting information
p. 6392 - 6398
(2013/07/25)
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- Whole-cell yeast-mediated preparation of (R)-2-chloro-1-(3-nitrophenyl) ethanol as a synthetic precursor for (R)-phenylephrine
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The incubated whole-cell biocatalyst of Pichia minuta JCM 3622 reduced 2-chloro-1-(3-nitrophenyl)ethanone to provide (R)-2-chloro-1-(3-nitrophenyl) ethanol with 99.2% ee in 87% isolated yield in the presence of Amberlite XAD-7 as a reservoir for the hydrophobic, crystalline and toxic substrate. The product was transformed to (R)-1-(3-hydroxyphenyl)-2-methylaminoethanol (phenylephrine, 1a), a selective α1-adrenergic receptor agonist, in 98.0% ee over five steps.
- Tokoshima, Daisuke,Hanaya, Kengo,Shoji, Mitsuru,Sugai, Takeshi
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- Mild and efficient α-chlorination of carbonyl compounds using ammonium chloride and oxone (2KHSO5·KHSO4· K2SO4)
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A simple protocol for the α-monochlorination of ketones and 1,3-dicarbonyl compounds utilizing NH4Cl as a source of chlorine and Oxone as an oxidant in methanol without catalyst is presented. The reaction proceeds at ambient temperature in yields ranging from moderate to excellent.
- Swamy, Peraka,Kumar, MacHarla Arun,Reddy, Marri Mahender,Narender, Nama
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supporting information; experimental part
p. 432 - 434
(2012/06/01)
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- The use of sodium chlorate/hydrochloric acid mixtures as a novel and selective chlorination agent
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Sodium chlorate/hydrochloric acid mixtures were used to chlorinate activated arenes and the α-position of ketones. This chlorination method was used to produce selectively mono-, di-, and trichlorinated compounds by controlling the molarity of sodium chlorate. This reagent proved to be much more efficient and easier to handle than chlorine gas.
- Moon, Byung Seok,Choi, Han Young,Koh, Hun Yeong,Chi, Dae Yoon
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experimental part
p. 472 - 476
(2011/12/04)
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- Simple and efficient methods for selective preparation of α-mono or α,α-dichloro ketones and β-ketoesters by using DCDMH
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New processes that can selectively prepare α-mono or α,α-dichloro ketones and β-ketoesters using 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) are reported. Using silica gel as the catalyst and methanol as the solvent and heating for 1 h under reflux, α-monochlorinated products were selectively obtained in 86-98% yield. However using a deep eutectic solvent (choline chloride: p-TsOH = 1:1) as the solvent and stirring for 45 min at room temperature, α,α- dichlorinated products were selectively obtained in 86-95% yield.
- Chen, Zizhan,Zhou, Bin,Cai, Huihua,Zhu, Wei,Zou, Xinzhuo
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experimental part
p. 275 - 278
(2010/04/22)
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- Process for the preparation of tricyclic amino alcohol derivatives
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A process for the preparation of tricyclic amino alcohol derivatives including 2-[N-[2-(9H-carbazol-2-yloxy)ethyl]]amino-1-[(3-methylsulfonylamino)phenyl]ethanol useful in the treatment of diabetes, obesity, hyperlipidemia and so on; and intermediates as represented by formula (5) or (6) or the like useful in the preparation, wherein R11 is hydrogen or the like; and *1 represents an asymmetric carbon atom. 2-Halo-1-(3-nitrophenyl)ethanone derivatives and 1-(3-nitrophenyl)oxirane derivatives, which are intermediates for the preparation of tricyclic amino alcohol derivatives, are easy of purification, and particularly optically active 1-(3-nitrophenyl)oxirane derivatives are effective in enhancing the optical purities of the final products.
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- Ozone-mediated Nitration of Aromatic Ketones and Related Compounds with Nitrogen Dioxide
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Alkyl aryl ketones react smoothly with nitrogen dioxide at low temperatures in the presence of ozone to give ortho- and meta-nitro derivatives as the principal products, the former usually being predominant (ortho:meta = 1.1-3.8:1.0).No attack was observed on the alkyl side chains.
- Suzuki, Hitomi,Murashima, Takashi
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p. 903 - 908
(2007/10/02)
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- INVESTIGATIONS ON REACTIONS OF CHLORINE DIOXIDE AND SODIUM CHLORITE WITH ORGANIC COMPOUNDS. PART XXXV. REACTIONS OF CHLORINE DIOXIDE WITH RING-SUBSTITUTED STYRENES
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Reactions of chlorine dioxide with ring substituted styrenes (1a-n) in carbon tetrachloride at 52-54 deg C were studied.The reaction products were isolated and characterised.It has been found that methyl-, chloro-, nitrostyrenes and 4-methoxystyrene are attacked by chlorine dioxide exclusively on the vinyl group, to yield the corresponding α-chloroacetophenones (2), diastereoisomers of β-chlorostyrene (6,7), oxidation products (8,9) and some polymers.Oxidation of its phenolic hydroxyl groups and vinyl polymerization took place in hydroxystyrenes.
- Kwiecien, Halina,Jalowiczor, Jozef
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p. 811 - 824
(2007/10/02)
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- REACTION DE L'ACIDE PERCHLORIQUE SUR LES PHENYLACETYLENES SUBSTITUES. MISE EN EVIDENCE D'UN MECANISME IONIQUE ET RADICALAIRE
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We have studied the reaction of perchloric acid in acetic acid medium on some substituted phenylacetylenes.The ionic and radicalar mechanism is in agreement with the formation of and alkenyl perchlorate which is decomposed according to an homolytic process.
- Montheard, Jean-Pierre,Camps, Marcel,Benzaid, Ahmed,Pascal, Jean-Louis
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p. 3483 - 3486
(2007/10/02)
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