- One-Pot Sequential Multistep Transformation of α,β-Unsaturated Trifluoromethyl Ketones: Facile Synthesis of Trifluoromethylated 2-Pyridones
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A one-pot transformation of α,β-unsaturated trifluoromethyl ketones with 2-(phenylsulfinyl)acetamide to give trifluoromethylated 2-pyridones is realized. The reaction proceeds under mild conditions and involves multiple steps in an expeditious and controlled sequence to provide efficient access to a broad range of trifluoromethylated 2-pyridones in moderate to high yields. Moreover, further synthetic manipulations permit the routine synthesis of a diverse array of trifluoromethylated pyridines with good efficiency.
- Lv, Ning,Tian, Yi-Qiang,Zhang, Fa-Guang,Ma, Jun-An
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p. 605 - 609
(2019/03/07)
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- Trifluoromethylation process for bromo-pyridine and derivatives thereof
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The invention belongs to the field of organic chemistry and relates to a trifluoromethylation process for bromo-pyridine and derivatives thereof. The process disclosed by the invention comprises the following steps: by taking a bromo-pyridine compound with a formula a structure as a raw material, performing trifluoromethylation under the action of a Maben reagent fluoro-S-( trifluoromethyl)-dibenzothiophene salt having a formula c structure, thereby obtaining the tirfluoromethylpyridine compound with a formula b structure. The structural formula is as shown in the specification. In the formula, X- is Bronst conjugate base, R is H or -CN or halogen or C1-C6 alkyl or C1-C6 alkoxy or -OH or -R1OH or COR2 or -CO2R3 or -CONR4 or -NR5R6; R1 is C1-C6 akyl; R2, R3 and R4 are identically or differently H or C1-C6 alkyl; and the R5 and R6 are identically or differently H or O or C1-C6 alkyl or C1-C6 alkoxy.
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Paragraph 0051-0053
(2018/07/30)
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- PROCESS FOR THE PREPARATION OF 2-TRIFLUOROMETHYL ISONICOTINIC ACID AND ESTERS
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The invention relates to a novel process for the preparation of 2- trifluoromethyl isonicotinic acid and esters of the formula I which involves a palladium catalysed carbonylation or cyanation step wherein R1 is hydrogen or Q1-6-alkyl. The 2-trifluoromethyl isonicotinic acid and esters of the formula I are versatile intermediates for the preparation of active pharmaceutical and agrochemical agents such as for instance TAAR 1 agonists of the formula III.
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- Recommendable routes to trifluoromethyl-substituted pyridine- and quinolinecarboxylic acids
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As part of a case study, rational strategies for the preparation of all ten 2-, 3-, or 4-pyridinecarboxylic acids and all nine 2-, 3-, 4-, or 8-quinolinecarboxylic acids bearing trifluoromethyl substituents at the 2-, 3-, or 4-position were elaborated. The trifluoromethyl group, if not already present in the precursor, was introduced either by the deoxygenative fluorination of suitable carboxylic acids with sulfur tetrafluoride or by the displacement of ring-bound bromine or iodine by trifluoromethylcopper generated in situ. The carboxy function was produced by treatment of organolithium or organomagnesium intermediates, products of halogen/metal or hydrogen/ metal permutation, with carbon dioxide. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Cottet, Fabrice,Marull, Marc,Lefebvre, Olivier,Schlosser, Manfred
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p. 1559 - 1568
(2007/10/03)
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- The direct metalation and subsequent functionalization of trifluoromethyl-substituted pyridines and quinolines
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Depending on the choice of the reagent, 2-(trifluoromethyl)-pyridine can be selectively metalated and subsequently carboxylated of otherwise functionalized either at the 3- or at the 6-position. "Optional site selectivity" can also be achieved with 4-(trifluoromethyl)pyridine, which may be deprotonated either at the 2- or at the 3-position. In contrast, 3-(trifluoromethyl)pyridine undergoes nucleophilic addition and ensuing decomposition whatever the base. Depending on the reaction conditions, 2-(trifluoromethyl)quinoline displays reactivity toward lithium reagents at its 3-, 4-, or 8-positions, 3-(trifluoromethyl)quinolines at the 2- or 4-positions, and 4-(trifluoromethyl)quinoline at the 2- or 3-positions. It was therefore possible to prepare four trifluoromethyl-substituted pyridinecarboxylic acids (1, 4, 9, and 10) and six trifluoromethyl-substituted quinolinecarboxylic acids (11, 13, 14, 15, 17, and 18) regioisomerically uncontaminated and in a most straightforward way. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Schlosser, Manfred,Marull, Marc
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p. 1569 - 1575
(2007/10/03)
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