- Preparation method of 2-chloro-4-fluoro-5-nitrobenzaldehyde
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The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of 2-chloro-4-fluoro-5-nitrobenzaldehyde. The method comprises the following steps: taking 2-chloro-4-fluorotoluene as a raw material, introducing ch
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- Preparation method of 2-chlorine-4-fluorine-benzaldehyde
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The invention relates to a preparation method of 2-chlorine-4-fluorine benzaldehyde, and the method comprises the following steps: under stirring, adding 4-fluorine benzaldehyde into an acid solution,heating to 40-80 DEG C, and adding a chloramine chlorination reagent for reaction, cooling to room temperature, and carrying out after-treatment on the reaction solution to obtain the 2-chlorine-4-fluorine benzaldehyde, wherein the chloramine chlorination reagent is added in three batches: the first batch of chloramine chlorination reagent is added for reaction for 4 hours, then the second batchof chloramine chlorination reagent is added for reaction for 4 hours, finally the third batch of chloramine chlorination reagent is added to continuously react for 12 to 24 hours until the reaction iscompleted. According to the method disclosed by the invention, the yield of the product is 85wt%-94wt%. The raw materials involved in the method are commercialized reagents which are cheap and easy to obtain, the chloramine chlorination reagent is an environment-friendly reagent, the reaction only needs one step, and the product is simple and convenient to purify; and the method provided by the invention has good industrial potential and application value.
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Paragraph 0037-0063
(2020/12/30)
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- TEMPO-mediated oxidation of primary alcohols to aldehydes under visible light and air
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A homogeneous visible light photoredox TEMPO-mediated selective oxidation of primary alcohols to the corresponding carbonyl compounds was developed using molecular oxygen from air as the terminal oxidant. Ru(bpy)3(PF 6)2 (bpy: bipyridyl) and Ir(dtb-bpy)(ppy) 2(PF6) (dtb-bpy: 4,4′-di-tert-butyl-2,2′- bipyridyl; ppy: 2-phenylpyridine) were used as the sensitizers. A homogeneous visible light photoredox TEMPO-mediated selective oxidation of primary alcohols to the corresponding carbonyl compounds was developed. Molecular oxygen from air was the terminal oxidant. Copyright
- Liu, Dongwang,Zhou, Hongxia,Gu, Xiangyong,Shen, Xiaoqin,Li, Pixu
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supporting information
p. 117 - 122
(2014/03/21)
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- Application of flow chemistry to the selective reduction of esters to aldehydes
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The reduction of esters to aldehydes is an important transformation in organic chemistry and several reducing agents have been described. However, the use of this reaction in medicinal and natural product chemistry is limited due to the instability of the intermediates and the high reactivity of the reaction products. In the current article, the general and selective reduction of esters with diisobutyl-tert-butoxyaluminum hydride in flow is reported. This reagent allows esters to be reduced in the presence of different functional groups, including those considered to be of similar or higher reactivity. Copyright
- De Munoz, Juan M.,Alcazar, Jesus,De La Hoz, Antonio,Diaz-Ortiz, Angel
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supporting information; experimental part
p. 260 - 263
(2012/02/16)
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- 'HALEX' FLUORINATION OF CHLORINATED BENZALDEHYDES AND BENZOYL CHLORIDES
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Spray-dried potassium fluoride, suspended in sulpholane at 220 degC, converted 2,4- and 2,6-dichlorobenzaldehyde into the corresponding difluoroaldehydes (yields ca. 65percent).Small amounts of the mono-substituted products (2-chloro-4-fluoro- + 4-chloro-2-fluorobenzaldehyde, and 2-chloro-6-fluoro-benzaldehyde, respectively) were also produced.Similar treatment of the 3,4-dichloro-analogue gave 3-chloro-4-fluorobenzaldehyde (yield 98percent, conversion 68percent), but 2- and 4-chlorobenzaldehyde gave very poor yields (ca. 5percent) of the 2- and 4-fluoro-derivatives. 2-Fluoro-, 4-fluoro- and 3-chloro-4-fluorobenzoyl fluoride were obtained (yields 60-65percent) by heating the corresponding chlorobenzoyl chlorides with potassium fluoride in sulpholane.
- Banks, R. Eric,Mothersdale, Kevin N.,Tipping, Anthony E.,Tsiliopoulos, Efthimios,Cozens, Barry J.,et al.
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p. 529 - 537
(2007/10/02)
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- Herbicidal triazolinones
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A herbicidal compound which is a Q-substituted 1-aryl-4,5-dihydro-1,2,4-triazol-5(1H)-one in which the Q-substituent is on the ring-carbon atom at the 5-position of the aryl group and in which: Q is (a) --CH(R1)ZR in which Z is O or S(O)n and n is zero, one or two; or (b) --CH(R1)N(R4)(R5); or (c) --C(R9)=NR6 ; or STR1
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- Herbicidal aryl tetrahydrophthalimides
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A herbicidal compound of the formula STR1 where X is F, Cl or Br, Y is Cl, Br, CHF2 O or CF3, R is alkyl of 1 to 6 carbon atoms or lower halo alkyl and R' is H or lower alkyl. Related compounds, including those which have --SR or --NR2 R in place of --OR are also disclosed.
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- An Unusual Fluorine Atom Rearrangement in the Photocyclization of 1-Fluorohelicenes
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Oxidative photocyclization of 1-fluorohelicene and two of its chlorine-substituted derivatives leads to the formation of 8-fluorobenzoperylenes through an unprecedented inter-ring fluorine atom migration; photoelimination of HF to give benzoperylenes also occurs as a competing process.The rearrangement pathway predominates when the irradiation is carried out at 0 deg C in air-saturated benzene solution containing 10 -3 M iodine; the elimination pathway predominates at higher temperatures or in the absence of either oxygen or iodine.The rearrangement isrationalized by postulating a triplet-state photocyclization to give a dihydrobenzoperylene intermediate, followed by abstraction of the tertiary hydrogen atom from that intermediate to give a radical that subsequently undergoes a fluorine atom shift by an SNi'mechanism.
- Mallory, Frank B.,Mallory, Clelia W.
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p. 526 - 532
(2007/10/02)
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