- Transition-metal-free decarboxylative halogenation of 2-picolinic acids with dihalomethane under oxygen conditions
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A convenient and efficient method for the synthesis of 2-halogen-substituted pyridines is described. The decarboxylative halogenation of 2-picolinic acids with dihalomethane proceeded smoothly via N-chlorocarbene intermediates to afford 2-halogen-substituted pyridines in satisfactory to excellent yields under transition-metal-free conditions. This new type of decarboxylative halogenation is operationally simple and exhibits high functional-group tolerance.
- Zhang, Xitao,Feng, Xiujuan,Zhang, Haixia,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 5565 - 5570
(2019/10/22)
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- Preparation method of non-transition metal-catalyzed 2-halogenated pyridine compound
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The invention provides a preparation method of a non-transition metal-catalyzed 2-halogenated pyridine compound. The 2-halogenated pyridine compound is an important component of many medicines and bioactive molecules and has important application in the fields of organic synthesis, medicinal chemistry and the like and wide market prospects. The invention relates to the preparation method of the non-transition metal-catalyzed 2-halogenated pyridine compound. According to the method, pyridine-2-carboxylic acid, derivatives of the pyridine-2-carboxylic acid, NaF, KF, CsF, TBAF, NaCl, KCl, CsCl, TBAC, NCS, NaBr, KBr, CsBr, Br2, TBAB, NBS, NaI, KI, CsI, I2 and NIS are used as raw materials, and under the presence of base and an accelerant and mild conditions, the 2-halogenated pyridine compoundis synthesized. The method has the advantages that the steps are simple, the raw materials are easy to obtain, the reaction conditions are mild and the like; the method has great use value and socialand economic benefits.
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Paragraph 0064-0066
(2018/10/11)
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- Method for producing 2-chloro-4-trifluoromethylpyridine
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The invention discloses a method for producing 2-chloro-4-trifluoromethylpyridine, and belongs to the technical field of fine chemical synthesis. The method comprises the following steps: taking 2-amino-4-methylpyridine as a raw material, and successively carrying out diazotization, chlorination and fluoridation on the 2-amino-4-methylpyridine to obtain 2-chloro-4-trifluoromethylpyridine. The diazotization comprises the following steps: taking the 2-amino-4-methylpyridine as the raw material, and carrying out diazotization on the 2-amino-4-methylpyridine, sodium nitrite and hydrogen chloride in a reactor to obtain 2-chloro-4-methylpyridine. The chlorination comprises the following steps: taking the 2-chloro-4-methylpyridine as the raw material, feeding chlorine and carrying out chlorination to obtain 2-chloro-4-(trichloromethyl) pyridine as a main product and hydrogen chloride as a side product. The fluoridation comprises the following steps: taking the 2-chloro-4-(trichloromethyl) pyridine as the raw material, and carrying out fluoridation on the 2-chloro-4-(trichloromethyl) pyridine and anhydrous hydrogen fluoride in an autoclave to obtain the 2-chloro-4-trifluoromethylpyridine as a main product. Industrial production of the 2-chloro-4-trifluoromethylpyridine is realized.
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Paragraph 0023; 0027
(2017/09/19)
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- Preparation of an Arenylmethylzinc Reagent with Functional Groups by Chemoselective Cross-Coupling Reaction of Bis(iodoazincio)methane with Iodoarenes
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Palladium-catalyzed cross-coupling reaction of bis(iodozincio)methane with iodoarenes carrying various functionalities such as ester, boryl, cyano, and halo groups proceeded chemoselectively to give the corresponding arenylmethylzinc species efficiently. The moderate reactivity of the gem-dizinc reagent imparted functional group tolerance to the process. The transformations from iodoheteroarenes were also performed; in the case of iodopyridine derivatives, the nickel-catalyzed reaction gave the corresponding organozinc species efficiently. The obtained arenylmethylzinc species underwent the copper-mediated coupling reaction with a range of organic halides.
- Shimada, Yukako,Haraguchi, Ryosuke,Matsubara, Seijiro
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p. 2395 - 2398
(2015/10/19)
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- Chemoselective sp 2-sp3 cross-couplings: Iron-catalyzed alkyl transfer to dihaloaromatics
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The chemoselective functionalization of a range of dihaloaromatics with methyl, cyclopropyl, and higher alkyl Grignard reagents via iron-catalyzed cross-coupling is described. The site selectivity of C-X (X = halogen) activation is determined by factors such as the position of the halogen on the ring, the solvent, and the nucleophile. A one-pot protocol for the chemoselective synthesis of mixed dialkyl heterocycles is achieved solely employing iron catalysis.
- Malhotra, Sushant,Seng, Pamela S.,Koenig, Stefan G.,Deese, Alan J.,Ford, Kevin A.
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supporting information
p. 3698 - 3701
(2013/08/23)
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- BACTERICIDE COMPOSITION AND METHOD OF CONTROLLING PLANT DISEASE
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It is to provide a fungicidal composition having stable and high fungicidal effects against cultivated crops infected with plant diseases resulting from plant diseases. A fungicidal composition containing as active ingredients (a) a benzoylpyridine derivative represented by the formula (I) or its salt: (wherein X is a halogen atom, a nitro group, a substitutable hydrocarbon group, a substitutable alkoxy group, a substitutable aryloxy group, a substitutable cycloalkoxy group, a hydroxyl group, a substitutable alkylthio group, a cyano group, a carboxyl group which may be esterified or amidated, or a substitutable amino group, n is 1, 2, 3 or 4; R1 is a substitutable alkyl group, R2' is a substitutable alkyl group, a substitutable alkoxy group, a substitutable aryloxy group, a substitutable cycloalkoxy group or a hydroxyl group, p is 1, 2 or 3, and R2" is a substitutable alkoxy group or a hydroxyl group, provided that at least two of R2' and R2" may form a condensed ring containing an oxygen atom) and (b) at least one another fungicide.
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Page/Page column 20-21
(2008/06/13)
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- Reaction of N-fluoropyridinium fluoride with isonitriles: A convenient route to picolinamides
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Reaction of N-fluoropyridinium fluoride generated in situ with a series of isonitriles led to the formation of the corresponding picolinamides in good yields. A similar reaction sequence for quinoline yielded the respective derivatives of 2-quinoline carboxylic acid. The proposed reaction mechanism involves the intermediate formation of a highly reactive carbene species.
- Kiselyov, Alexander S.
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p. 2279 - 2282
(2007/10/03)
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- Facile and Selective Synthesis of Chloromethylpyridines and Chloropyridines Using Diphosgene/Triphosgene
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Diphosgene and triphosgene in the presence of amines were found to be an excellent chlorinating agents with high selectivity for the preparation of chloromethylpyridines and chloropyridines from picoline-N-oxides and pyridine-N-oxides respectively.
- Narendar,Gangadasu,Ramesh, Ch.,Raju, B. China,Rao, V. Jayathirtha
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p. 1097 - 1103
(2007/10/03)
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- Stabilised 2,3-pyridyne reactive intermediates of exceptional dienophilicity
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The enhanced dienophilicity of 4-methoxy, 4-aryloxy and 4-thiophenoxy analogues 6-9 of 2,3-pyridyne (2) relative to 2 itself is reported. The regioselective lithiation of 4-alkoxy-(22, 23 and 25) and 4-thiophenoxy-2- chloropyridme (24) at low temperatures, followed by elimination of lithium chloride affords 4-alkoxy- and 4-thiophenoxypyridynes, which can be trapped in situ in a [4+2] cycloaddition reaction with furan to give endoxides 28-31 in moderate to good yields (25-58%). In contrast, precursors with a hydrogen (18) or methyl (12) substituent at C-4 give no evidence for pyridyne formation under these conditions. Attempts to generate 6-isopropoxy-2,3-pyridyne (10) from the low-temperature lithiation of 2-chloro-6-isopropoxypyridine were unsuccessful due to the instability of the 2-chloro-6-isopropoxy-5-lithiopyridine. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Connon, Stephen J.,Hegarty, Anthony F.
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p. 3477 - 3483
(2007/10/03)
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- N-(phenylsulfonyl)picolinamide derivatives, process for producing the same, and herbicide
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A herbicide containing as the active ingredient an N-(henylsulfonyl)picolinamide derivative represented by general formula (I) wherein X reprcsents a halogeno, a C1-4 alkyl, a C1-4 haloalkyl, a C1-4 alkoxy, a C1-4 haloalkoxy, a (C1-4 alkoxy)carbonyl, a [di(C1-4 alkyl)amino]sulfonyl, an [N—(C1-4 alkyl)-N—(C1-4 alkoxy)amino]sulfonyl, a (C1-4 alkylamino)sulfonyl, a C1-4 alkylthio, a C1-4 alkylsulfinyl, a C1-4 alkylsulfonyl, or nitro; n is an integer of 0 to 5; Y represets a halogeno, a C1-4 alkyl, a C1-4 haloalkyl, a C1-4 alkoxy, C1-4 haloalkoxy, a C1-4 alkylthio, a C1-4 haloalkylthio, amino, a C1-4 alkylamino, a di(C1-4 alkyl)amino, a (C1-4 alkoxy) C1-4 alkyl, a (C1-4 alkylthio) C1-4 alkyl, or nitro; and m is an integer of 0 to 4. This active ingredient is synthesized by condensing a substituted picolinic acid with a substituted benzenesulfonamide under dehydration, or by reacting the phenyl ester of a substituted picolinic acid with a substituted benzenesulfonamide in the presence of a basic compound.
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- Side-chain retention during lithiation of 4-picoline and 3,4-lutidine: Easy access to molecular diversity in pyridine series
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The first direct ring-selective lithiation of 4-picoline and 3,4-lutidine has been achieved through the use of BuLi/LiDMAE aggregates to prevent the usual side-chain metallation. Several functionalities have been introduced at the C-2, C-6 and C-5 positions by ring-selective sequential lithiation, opening a simple and fast route to polysubstituted pyridine building blocks. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Kaminski, Thomas,Gros, Philippe,Fort, Yves
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p. 3855 - 3860
(2007/10/03)
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- Vitronectin receptor antagonists
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Compounds of the formula (I) are disclosed which are vitronectin receptor antagonists and are useful in the treatment of osteoporosis: or a pharmaceutically acceptable salt thereof.
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- 6-(Nonsubstituted or substituted) phenoxy picolinic acids, process of preparing the same, and agricultural/horticultural germicides containing the same
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An agricultural or horticultural fungicide containing 6-(unsubstituted or substituted) phenoxy picolinic acid represented by the general formula (I), as an effective ingredient. wherein R is a halogen atom, a C1to C4alkyl group, a C1to C4haloalkyl group, a C1to C4alkoxy group, a C1to C4haloalkoxy group, a C1to C4alkylthio group, a C1to C4alkylamino group, a di(C1to C4alkyl)amino group or a C7to C8aralkyl(C1to C4alkyl)amino group; n2is an integer of 0 to 3; Y is a C1to C4alkyl group, a C1to C4haloalkyl group, a C1to C4alkoxy group, a C1to C4haloalkoxy group, a C1to C4alkylthio group, a C1to C4haloalkylthio group or a halogen atom; and m is an integer of 0 to 5, and when m and n2are not less than 2, Rs and Ys may be the same or different, respectively. The compound is useful as an effective ingredient of agricultural or horticultural fungicides.
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- Diels-Alder cycloadditions of stabilised 2,3-pyridynes
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Investigation of electron donating substituents at C-4 on 2,3-pyridyne 1 stability has revealed a novel stabilisation of these reactive species by aryloxy and thiophenoxy groups leading to a relatively high yielding [4+2] cycloaddition between 4-(p-methoxyphenoxy)-2,3-pyridine and furan at low temperature.
- Connon, Stephen J.,Hegarty, Anthony F.
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p. 735 - 737
(2007/10/03)
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- 6-phenoxy picolinic acid alkylidene hydrazide derivative, process for producing the same and herbicide using the same
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PCT No. PCT/JP98/02842 Sec. 371 Date Feb. 23, 2000 Sec. 102(e) Date Feb. 23, 2000 PCT Filed Jun. 25, 1998 PCT Pub. No. WO99/00370 PCT Pub. Date Jan. 7, 1999A 6-phenoxy picolinic acid alkylidene hydrazide derivative, a process for producing the derivative and a herbicide containing the derivative as an effective ingredient. Such a compound is a novel compound and is useful as an effective ingredient of herbicides.
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- Method of preparing 2-chloro-pyridinemethanol
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The invention relates to a method of preparing 2-chloro-pyridinemethanol represented by the following formula (1). The method includes the steps of: (a) reacting 2-chloro-monochloromethylpyridine with an alkali metal salt of a carboxylic acid and/or a hydrate of the alkali metal salt so as to form an ester derivative; and (b) hydrolyzing the ester derivative so as to form the 2-chloro-pyridinemethanol. STR1
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- On the High-Yielding Chlorodediazonation not requiring Catalysis by Copper Salts
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Reaction of benzenediazonium tetrafluoroborate, p-methoxybenzenediazonium tetrafluoroborate, p-ethoxycarbonylbenzenediazonium tetrafluoroborate and 3-pyridinediazonium tetrafluoroborate in a 3:1 mixture of tetrachloromethane and acetonitrile with ferrous and ferric chloride yields the corresponding aryl chlorides in nearly quantitative yield.The reaction mechanism seems to be similar to that of the classical Sandmeyer reaction involving an initial electron transfer from the reductant to the arenediazonium ion.On the other hand, treatment of 2-aminopyridine or 2-amino-4-methylpyridine with dinitrogen trioxide in dry dichloromethane in the presence of hydrogen chloride and tetrabutylammonium chloride but in the absence of redicing agents afforded 2-chloropyridine or 2-chloro-4-methylpyridine, respectively, in 95 percent yield in a reaction which either has a cation as intermediate or follows an SNAr mechanism.The reactivity of the diazonium ion seems to determine whether the chlorodediazoniation goes through an aryl radical or follows another route, possibly via the SNAr mechanism or the cation; most arenediazonium ions seem to react through the aryl radical, while 2-pyridinediazonium and most alkyldiazonium ions react via other routes.
- Daasbjerg, Kim,Lund, Henning
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p. 157 - 162
(2007/10/02)
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- Utilizing Acetyl Hypofluorite for Chlorination, Bromination, and Etherification of the Pyridine System
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Acetyl hypofluorite, which is easily made from F2, possesses a strong electrophilic fluorine.This electrophile is able to attach itself to the nitrogen atom of pyridine and activate the ring toward nucleophilic attacks.The ultimate elimination of HF results in an overall easy nucleophilic displacement of the hydrogen of the important 2-position .The nucleophiles used: Clδ-, Brδ-, ROδ-, originate from solvents such as CH2Cl2, CH2Br2, and various primary alcohols.Thus, 2-halo- or 2-alkoxypyridines were formed.The reaction conditions (room temperature, very short reaction times, and good yields) transform the task of direct substitution of the pyridine ring from an extremely difficult to a very easy procedure.
- Hebel, David,Rozen, Shlomo
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p. 6298 - 6301
(2007/10/02)
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- Pyri(mi)dyl-oxy-and -thio-benzoic acid derivatives useful as herbicides and plant growth regulants
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New pyri(mi)dyl-oxy- or -thio-benzoic acid derivatives of the formula STR1 are taught which have herbicidal and plant growth regulating activity. In the formula Z can be Ch or N, X is oxygen or sulphur, A is oxygen, sulphur, a radical R5 --N=or a radical R6 O--N=and B is oxygen, sulphur, a radical STR2 with the proviso that at least one of the radicals R1, R2 or R3 represents alkyl or a part of a 3- to 6-membered fused carbocyclic ring.
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- Synthesis of 2-Substituted 4-Pyridylpropionates. Part 2. Alkylation Approach
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A synthesis of methyl 3-(2-methoxy-4-pyridyl)propionate (2), a key intermediate in the synthesis of the potent long-acting histamine H2-receptor antagonist SK&F 93574 (1), is described.The key step in the synthesis of compound (1) involves alkylation of 2-methoxy-4-methylpyridine (5) with sodium chloroacetate in the presence of sodamide.The scope and limitations of the alkylation is investigated using a variety of electrophiles.The application of this reaction to other 2-substituted 4-methylpyridines is also discussed.
- Adger, Brian M.,Ayrey, Peter,Bannister, Robin,Forth, Michael A.,Hajikarimian, Yousef,et al.
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p. 2791 - 2796
(2007/10/02)
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