cas 18368-64-4, 2-Chloro-5-methylpyridine | Articles data

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Convenient access to new chiral ferroceno-(iso)quinolines
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Mamane, Victor,Fort, Yves
p. 8220 - 8223
(2005)
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Method for preparing 2-chloro-5-substituted pyridine
The invention belongs to the technical field of chemical synthesis of pesticides, and particularly relates to a method for preparing 2-chloro-5-substituted pyridine, in particular to a method for preparing 2-chloro-5-methylpyridine. The method comprises the following steps: reacting amide as shown in a formula C which is used as a raw material in the presence of a chlorinating agent and N, N-dimethylformamide, and distilling after the reaction is finished to obtain the 5-substituted 2-chloropyridine as shown in a formula I which is described in the specification. When the 5-substituted 2-chloropyridine is prepared from the compound with the structure shown in the formula C, the by-product is allyl chloride (or homologues thereof) with small molecular weight, the boiling point of the by-product is obviously different from that of the product, the reaction conversion rate and the yield are higher than those of the prior art, the by-product is easy to separate from the product, and the by-product is more beneficial to recovery; therefore, according to the preparation method, the equipment investment can be greatly saved, the production cost is reduced, and the operation procedure is simplified; and in the route, the amine with lower price is used as a starting raw material, so that the production cost is reduced.
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Paragraph 0015; 0061-0064; 0065; 0068

(2021/09/21)

Efficient Phosphorus-Free Chlorination of Hydroxy Aza-Arenes and Their Application in One-Pot Pharmaceutical Synthesis
The chlorination of hydroxy aza-arenes with bis(trichloromethyl) carbonate (BTC) and SOCl2 has been effectively performed by refluxing with 5 wt % 4-dimethylaminopyridine (DMAP) as a catalyst. Various substrates are chlorinated with high yields. The obtained chlorinated aza-arenes can be used directly with simple workup for succedent one-pot synthesis on a large scale.
Wang, Jian,Li, Yan-Hui,Pan, Song-Cheng,Li, Ming-Fang,Du, Wenting,Yin, Hong,Li, Jing-Hua
supporting information
p. 146 - 153
(2020/03/10)

A process for preparing 2 - chloro -5 - methyl pyridine method (by machine translation)
The invention belongs to the technical field of organic chemical industry, relates to 2 - chloro - 5 - methyl pyridine preparation method, more specifically, relates to a 5 - methyl - 3, 4 - dihydro pyridine - 2 (1 H) - one (hereinafter referred to as the: pyridone) and chlorine gas, first synthesis of 2 - hydroxy - 5 - methyl pyridine (hereinafter referred to as: synthetic azo), re-chlorinated preparing 2 - chloro - 5 - methyl pyridine. (by machine translation)
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Paragraph 0012; 0017; 0020

(2019/07/04)

Transition-metal-free decarboxylative halogenation of 2-picolinic acids with dihalomethane under oxygen conditions
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
supporting information
p. 5565 - 5570
(2019/10/22)

Preparation method of 2-chloro-5-methylpyridine
The invention provides a preparation method of 2-chloro-5-methylpyridine. The preparation method comprises the following steps: S1, mixing raw materials, including 5-methyl-3,4-dihydro-2(1H)-pyridone,a catalyst and a solvent, to obtain a mixed solution; S2, simultaneously introducing chlorine gas and a chlorinating agent into the mixed solution at a reaction temperature higher than the room temperature, and reacting to obtain a reaction solution containing the 2-chloro-5-methylpyridine. Due to simultaneous introduction of the chlorine gas and the chlorinating agent for a reaction in the method, a technological process of lowering the temperature and then raising the temperature is not required and the 2-chloro-5-methylpyridine is synthesized by a one-step method only, so that the technological process is simplified, and the technological complexity is reduced and can be relatively simple; in addition, experiments indicate that by the preparation method, the reaction yield can be increased and the product quality can be improved.
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Page/Page column 6-11

(2019/09/17)

Preparation method of pesticide intermediate 2-chloro-5-methyl pyridine
The invention discloses a preparation method of a pesticide intermediate 2-chloro-5-methyl pyridine. The preparation method comprises the following steps: adopting benzyl chloride, ammonia water and n-propanal as a starting material, and adopting a one-pot process to synthesize an intermediate (I); then using ion exchange resin as an acid-binding agent to carry out catalytic reaction, using acetylchloride as an acylation reagent to carry out acetylation, thereby obtaining an intermediate compound (II); and leading the intermediate compound (II), DMF (Dimethyl Formamide) and solid phosgene inan organic solvent to carry out cyclizing ring-closing reaction, thereby obtaining a target compound (I). The preparation method disclosed by the invention has the beneficial effects that the materials are cheap and easy to obtain, the reaction steps are fewer, the process operation is simple, the catalyst can be repeatedly utilized, the emission of three wastes is less, the process is pollution-free and environment-friendly, the product quality is good, the yield is high and the cost is low; the preparation method is very suitable for industrial production and has extremely-strong industrialapplication value.
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Paragraph 0019; 0036; 0041; 0042; 0050; 0055; 0056

(2019/02/08)

A 2 - chloro - 5 - methyl pyridine synthesis method
The present invention discloses a synthesis method of 2-chloro-5-methyl pyridine, and belongs to the technical field of pesticides. The method uses 2-amino-5-methylpyridine as the raw material. The method is as below: dissolving 2-amino-5-methylpyridine in concentrated hydrochloric acid; introducing excess of hydrogen chloride gas to generate saturation; dropwise adding nitric acid and thionyl chloride; after the reaction, neutralizing with alkali, layering, and separating an oil phase to obtain a product of 2-chloro-5-methyl pyridine. The method has the advantages of simple readily available raw materials, simple operation steps, rapid reaction, and simple separation of product.
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Paragraph 0020; 0022; 0024; 0026; 0027; 0028

(2018/03/26)

A chloro pyridine and its derivatives synthetic method
The invention discloses a method for synthesizing chloropyridines and derivatives thereof and belongs to the field of fine chemical industry. According to the method, aminopyridine and derivatives thereof undergo a reaction to generate chloropyridines and derivatives thereof. The method is characterized in that phosphorus trichloride, phosphorus oxychloride or thionyl chloride and nitric acid are added into a solution of aminopyridine and the derivatives of aminopyridine, and chloropyridines and derivatives of chloropyridines can be obtained by stirring and reaction. The method has the advantages of being simple to operate, high in yield and less in three wastes.
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Paragraph 0016; 0017

(2018/03/26)

2-chlorin-5-picoline preparation method
The invention discloses a 2-chlorin-5-picoline preparation method. According to the preparation method, 3-methylpyridine-N-oxide is utilized as a raw material, 2,4,6-triisopropyl-3-benzoyl chloride isutilized as a chlorinating agent, dichloromethane is utilized as a solvent, and chlorination reaction is performed under temperature of -20 to 50 DEG C to obtain 2-chlorin-5-picoline. According to the 2-chlorin-5-picoline preparation method disclosed by the invention, as the 2,4,6-triisopropyl-3-benzoyl chloride with a steric effect is utilized as the chlorinating agent, the defects that 2-chlorin-5-picoline prepared by a traditional method has poor selectivity and low yield are avoided, and yield of the 2-chlorin-5-picoline can be high as 95%; in addition, phosphorus oxychloride is preventedfrom being used, and the defect that phosphorus wastewater is difficult to treat is overcome.
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Paragraph 0019; 0021; 0022; 0023; 0025; 0028

(2018/04/03)

Continuous synthesis technology of 2-chloro-5-chloromethylpyridine
The invention provides a continuous synthesis technology of 2-chloro-5-chloromethylpyridine. The continuous synthesis technology comprises the following steps: under the action of a Vilsmeier reagent,propionaldehyde and a raw material A are subjected to a continuous cyclization reaction in a continuous synthesis reaction unit so as to obtain 2-chloro-5-methylpyridine, and 2-chloro-5-methylpyridine is continuously discharged and continuously conveyed into a chlorination unit, wherein the raw material A is selected from acetonitrile and/or acetamide; and in the chlorination unit, 2-chloro-5-methylpyridine and chlorine are subjected to a chlorination reaction to obtain 2-chloro-5-chloromethylpyridine. By the adoption of the continuous synthesis technology, reaction rate is raised, generationof by-products is reduced, and stability and safety of the synthesis process are also enhanced. In comparison with a batch synthesis technology, the invention has the following beneficial effects: bythe continuous process in the chlorination process, the risks that chlorine introduction speed is too fast, cooling is insufficient, cooling is interrupted, reaction heat is too late to move away, reaction is out of control and the like are reduced.
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Paragraph 0038-0042; 0048; 0058-0074

(2018/11/04)

Method for preparing 2-chlorine-5-methylpyridine
The invention discloses a method for preparing 2-chlorine-5-methylpyridine. The method comprises the following steps: (1) mixing N,N-dialkyl-5-methyl-2-pyridinamine with an organic solvent, adding a phase transfer catalyst, and heating to a reaction temperature; (2) under a reaction temperature condition, adding alkali and a quaternization reagent, controlling the pH value of a system, and performing distillation after the quaternization reaction to remove water; (3) heating a kettle material after water removal to a reaction temperature, adding a chlorination agent, and performing a heat-preservation reaction; (4) after chlorination is completed, desolventizing the kettle material, recycling a solvent, circulating and applying mechanically to the step (1), and recycling the chlorination agent and applying mechanically to the step (3); adjusting kettle residues with an alkali, and extracting with an organic solvent so as to obtain an extraction oil layer; (5) distilling the extractionoil layer so as to obtain 2-chlorine-5-methylpyridine, and recycling N,N-dialkyl-5-methyl-2-pyridinamine and circulating and applying mechanically to the step (1). The method is simple and environmental-friendly in process route, high in yield, good in selectivity and good in product quality.
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Paragraph 0033; 0035; 0036; 0037; 0041; 0045

(2018/09/26)

Synthesis method of 2-chloro-5-chloromethylpyridine
The invention discloses a synthesis method of 2-chloro-5-chloromethylpyridine. The synthesis method comprises the following main steps: 1, using 3-methylpyridine (I) as a main starting material and water as a reaction medium, performing a complete reaction on the 3-methylpyridine (I) and chlorine gas at 40-60 DEG C in the presence of a catalyst, and post-treating to obtain 2-chloro-5-methylpyridine (II) as a reaction raw material in the next step; 2, using the 2-chloro-5-methylpyridine (II) as the reaction raw material, in the presence or absence of a reaction medium, performing a complete reaction on the 2-chloro-5-methylpyridine (II) and the chlorine gas at 50-60 DEG C in the presence of the catalyst, and post-treating to obtain 2-chloro-5-chloromethylpyridine with the purity being higher than or equal to 99%. A reaction equation is as shown in the description. The method disclosed by the invention has the advantages of high reaction selectivity, stable product quality, simple production operation, increase in raw material utilization rate through combined use of the raw materials, reduction in production cost, and the like.
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Paragraph 0019-0029

(2018/04/03)

Preparation method of 2-chloro-5-methylpyridine
The invention discloses a preparation method of 2-chloro-5-methylpyridine, and belongs to the field of organic chemistry. According to the method, 2-amino-5-methylpyridine serves as the raw material and reacts with nitrosyl chloride under the existence of acyl chloride, and 2-chloro-5-methylpyridine is obtained. The production process is simple and convenient, the yield is high, and when metered based on 2-amino-5-methylpyridine, the yield can reach 94%.
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Paragraph 0020; 0021

(2017/02/09)

SOLID FORMS OF LUMACAFTOR, ITS SALTS AND PROCESSES THEREOF
Aspects of the present application relate to solid forms of Lumacaftor, its salts and processes thereof. Specific aspects of the present application relate to alternate processes for the preparation of Lumacaftor and intermediates thereof. Present application further relates to the solid forms of Lumacaftor and its salts.
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Page/Page column 51

(2017/11/04)

PROCESS FOR MAKING 2-CHLORO-5-METHYLPYRIDINE
Processes for the preparation of 2-chloro-5-methylpyridine are described.
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Paragraph 0066

(2017/01/31)

Preparation method of 2-chloro-5-methyl pyridine
The invention discloses a preparation method of 2-chloro-5-methyl pyridine, and belongs to the field of organic chemistry.With 2-amino-5-methyl pyridine as the raw material, under the existence of chloride, 2-amino-5-methyl pyridine reacts with nitrosyl chloride (NOC1) to form 2-chloro-5-methyl pyridine.The production process is simple and convenient, yield is high, and the yield can reach 96% according to 2-amino-5-methyl pyridine.
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Paragraph 0020; 0021

(2016/11/28)

Synthetic method of 4-(chloromethyl)-2-(3-(trifluoromethyl)phenoxy)pyridine
The invention relates to a synthetic method of 4-(chloromethyl)-2-(3-(trifluoromethyl)phenoxy)pyridine and belongs to the field of chemical synthesis.A traditional technology for producing 4-(chloromethyl)-2-(3-(trifluoromethyl)phenoxy)pyridine is backward, long in process, low in yield and large in three-waste amount and treatment is difficult.The synthetic method of the 4-(chloromethyl)-2-(3-(trifluoromethyl)phenoxy)pyridine is mild in reaction condition and high in yield.
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Paragraph 0007

(2016/10/09)

A pesticide intermediate 2-chloro-4-formylvaleronitrile method for the synthesis of
The invention belongs to the technical field of organic chemical industry, and relates to a synthetic method of a precursor of an imidacloprid pesticide intermediate 2-chloro-4-formyl valeronitrile. According to the synthetic method, propionaldehyde and chlorine gas are taken as initial raw materials, 2-chloride propyl aldehyde is prepared via substitution, and catalytic addition with acrylonitrile is carried out so as to obtain 2-chloro-4-formyl valeronitrile via synthesis, and total yield is stabilized to be higher than 70%. According to the synthetic method, chlorine substitution and addition two-step reaction is adopted, 2-chloro-4-formyl valeronitrile is prepared, the synthetic method is simple in technological process, low in production cost, and low in equipment investment, and is suitable for industrialized production, and raw material recovery is convenient to realize.
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Paragraph 0053-0054

(2017/05/04)

Preparation method of 2-chloro-5-picoline
The invention relates to a preparation method of 2-chloro-5-picoline. According to the method, benzyl chloride is taken as a raw material, benzaldehyde is taken as an inhibitor, ammonia is taken as an aminating agent, a product has a condensation reaction with propionaldehyde under the catalysis of an organic base, then a product has acetylation with an acetylation reagent, finally, a product performs cyclization under actions of N,N-dimethylformamide and triphosgene, and the target product 2-chloro-5-picoline is obtained through purification. The product purity is higher than or equal to 99.5%, and the total molar yield higher than 80% is realized. The preparation method of 2-chloro-5-picoline has good reaction selectivity, high yield and few three wastes, is simple to operate and facilitates industrialized production.
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Paragraph 0040; 0041

(2016/11/17)

PROCESS FOR MAKING 2-CHLORO-5-METHYLPYRIDINE
Processes for the preparation of 2-chloro-5-methylpyridine are described.
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Page/Page column 10

(2015/08/06)

Photocatalytic degradation of imidacloprid in soil: Application of response surface methodology for the optimization of parameters
The photocatalytic mineralization of imidacloprid (IMI) in soil to inorganic ions and the formation of various intermediates using TiO2 as the photocatalyst have been investigated under UV light. Various parameters, viz., catalyst concentration, soil depth and pH, intensity of light and initial concentration of IMI were optimized theoretically by using a central composite design based on a response surface methodology and were correlated with experimental results. The statistical analysis from the modelling results indicates that the degradation efficiency of IMI is affected by the depth of soil and the intensity of light, but the effects of the pH and the initial concentration of imidacloprid are more dominant. The optimum conditions obtained for the maximum degradation of imidacloprid were at pH = 3, intensity of UV light = 30 W m-2, soil depth = 0.2 cm and initial concentration of imidacloprid = 10 mg kg-1 of soil. Under these optimum conditions, the highest degradation efficiency of 83% was achieved after 18 h of UV light irradiation. The identification of various photoproduced intermediates of IMI by LC-MS analysis revealed its degradation, whereas the increase in the formation of inorganic ions with time of UV light irradiation confirms its mineralization. This journal is
Sharma, Teena,Toor, Amrit Pal,Rajor, Anita
p. 25059 - 25065
(2015/03/30)

Synthesis and molecular docking studies of novel 2-chloro-pyridine derivatives containing flavone moieties as potential antitumor agents
A series of novel 2-chloro-pyridine derivatives containing flavone, chrome or dihydropyrazole moieties as potential telomerase inhibitors were synthesized. The bioassay tests showed that compounds 6e and 6f exhibited some effect against gastric cancer cell SGC-7901 with IC50 values of 22.28 ± 6.26 and 18.45 ± 2.79 μg/mL, respectively. All title compounds were assayed for telomerase inhibition by a modified TRAP assay, the results showed that compound 6e can strongly inhibit telomerase with IC50 value of 0.8 ± 0.07 μM. Docking simulation was performed to position compound 6e into the active site of telomerase (3DU6) to determine the probable binding model.
Liu, Xin-Hua,Liu, Hui-Feng,Shen, Xu,Song, Bao-An,Bhadury, Pinaki S.,Zhu, Hai-Liang,Liu, Jin-Xing,Qi, Xing-Bao
scheme or table
p. 4163 - 4167
(2010/08/20)

Facile and selective synthesis of chloronicotinaldehydes by the Vilsmeier reaction
Eleven enamides were prepared by adopting different procedures. The various enamides prepared were subjected to Vilsmeier reaction using (i) POCl3/DMF; (ii) diphosgene/DMF; (iii) triphosgene/DMF leading to the formation of various multisubstituted chloronicotinaldehydes. Studies carried out indicate that Vilsmeier reagent concentration and the replacement of POCl3 by diphosgene or triphosgene, provides excellent selectivity and higher yields. Under modified reaction conditions one can get only chloronicotinaldehydes and not the chloropyridines as products. The various advantages in using diphosgene and triphosgene are illustrated. The mechanism of formation of chloronicotinaldehyde was discussed.
Gangadasu,Narender,Bharath Kumar,Ravinder,Ananda Rao,Ramesh,China Raju,Jayathirtha Rao
p. 8398 - 8403
(2007/10/03)

Reaction of N-fluoropyridinium fluoride with isonitriles: A convenient route to picolinamides
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.
p. 2279 - 2282
(2007/10/03)

Facile and Selective Synthesis of Chloromethylpyridines and Chloropyridines Using Diphosgene/Triphosgene
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
p. 1097 - 1103
(2007/10/03)

Unprecedented C-6 functionalisation of 3-picoline induced by a methyl to C-6 lithium shift
BuLi-Me2N(CH2)2OLi (BuLi-LiDMAE) promoted the clean C-6 functionalisation of 3-picoline via a methyl to C-6 lithium shift.
Mathieu, Julien,Gros, Philippe,Fort, Yves
p. 951 - 952
(2007/10/03)

N-substituted cis-n-propenyl-acetamides, and process for their preparation
The present invention relates to new N-substituted cis-N-propenyl-acetamides of the general formula (I) STR1 in which R1 represents in each case optionally substituted alkyl, -C(alkyl)2 -alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aralkyl or hetarylalkyl; a process for their preparation, and their use for the preparation of 2-chloro-5-methyl-pyridine.
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(2008/06/13)

Discovery of Ro 48-5695: A potent mixed endothelin receptor antagonist optimized from Bosentan
Implementation of a pyridylcarbamoyl group and an isopropylpyridylsulfonamide substituent as key components in the scaffold of Bosentan resulted in the identification of the potent orally active endothelin receptor antagonist Ro 48-5695. It shows affinities for ET(A) and ET(B) receptors in the low nanomolar range and high functional antagonistic potency in vitro.
Neidhart, Werner,Breu, Volker,Burri, Kaspar,Clozel, Martine,Hirth, Georges,Klinkhammer, Uwe,Giller, Thomas,Ramuz, Henri
p. 2223 - 2228
(2007/10/03)

Process for the preparation of 2-halogeno-pyridine derivatives
A process for the preparation of a 2-halogeno-pyridine of the formula STR1 in which X represents halogen and Y represents halogen, nitro, formyl, cyano, carboxyl, carbamoyl, alkyl, halogenoalkyl, alkoxyalkyl, dialkoxyalkyl, alkoxycarbonyl, alkylaminocarbonyl or dialkylaminocarbonyl, which comprises in a first stage reacting a pyridine 1-oxide of the formula STR2 with an organic nitrogen base A and an electrophilic compound, optionally in the presence of a diluent, to produce a compound of the formula STR3 in which A represents the radical of an organic nitrogen base, and Z- represents an anion formed from an electrophilic compound, optionally isolating and optionally purifying the compound of the formula (III).
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(2008/06/13)

Process for preparing 2-halo-5-substituted pyridines
Described are preferred processes for preparing 2-halo-5-substituted pyridine compounds. Preferred processes can be conducted in a one-step, one-pot fashion, and involve the reaction of a formamide and a halogenating agent with a nitrile such as cis-2-pentenonitrile or with a combination of reactants including an aldehyde such as n-propionaldehyde and a nitrile or an amide. Preferred processes provide for convenient and advantageous preparations of 2-chloro-5-methylpyridine, which serves as an intermediate to important insecticidal compounds.
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(2008/06/13)

Process for the preparation of 2-substituted 5-alkyl-pyridines
The title compounds of the formula STR1 can be prepared by cyclization of aminomethylenated 2-pentenoic acid derivatives of the formula STR2 where R, X, R1, R2 and Z have the meaning given in the description, in the presence of acids or ammonia. Preferably, aminomethylenated pentenoic acid derivatives are employed which can be prepared from pentenoic acid derivatives of the formula or with ortho-amides of the formula STR3 The meanings of A and B are also given in the description.
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(2008/06/13)

Process for the preparation of 2,5-disubstituted pyridines
2,5-Disubstituted pyridines of the formula STR1 can be prepared by reacting enamines of the formula STR2 with β-amino-acrylonitriles of the formula STR3 and treating the open-chain intermediate, which represents a R-R1 -5-amino-penta-2,4-dienonitrile, with protic acids or with ammonia.
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(2008/06/13)

Process for the preparation of 5-substituted 2-chloropyridines
A new process for the preparation of 5-substituted 2-chloropyridines of the general formula (I) STR1 is provided, in which R represents alkyl or arylalkyl, each of which is optionally substituted by halogen. The new process is characterised in that acetenamides of the general formula (II) STR2 in which R has the abovementioned meaning, and R1 represents alkyl or arylalkyl, each of which is optionally substituted by halogen, are reacted with a chlorinating agent in the presence of dimethylformamide and optionally in the presence of a diluent at temperatures between -30° C. and +150° C. The compounds (I) prepared according to the invention may be used inter alia as intermediates for the preparation of highly efficient insecticides.
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(2008/06/13)

Preparation of substituted 2-chloropyridines
A process for the preparation of a substituted 2-chloropyridine derivatives of the formula STR1 in which R1, R2, R3 and R4 represent hydrogen or various other radicals, which comprises reacting a pyridine-1-oxide of the formula STR2 with an aromatic carbonyl chloride in the presence of an inert organic solvent and in the presence of an acid acceptor at a temperature between about -20° C. and 200° C.
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(2008/06/13)

Preparation of 2-chloro-5-methyl-pyridine
A process for the preparation of 2-chloro-5-methylpyridine of the formula STR1 which comprises reacting 3-methyl-pyridine-1-oxide of the formula STR2 with a chlorinating agent of the formula STR3 in which R1 represents alkyl, halogenoalkyl, cycloalkyl, optionally substituted aryl, NR2 R3 or OR4 in which R2 and R3 individually represent alkyl, cycloalkyl or aryl or together represent alkanediyl or oxaalkanediyl and R4 represents alkyl, cycloalkyl or optionally substituted aryl, in the presence of a basic organic nitrogen compound and in the presence of a diluent at a temperature between about -20° C. and +150° C.
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(2008/06/13)

Preparation of 2-chloro-5- methyl-pyridine
In the preparation of 2-chloro-5-methyl-pyridine of the formula STR1 by reacting 3-methyl-pyridine-1-oxide of the formula STR2 with a chlorinating agent, the improvement which comprises effecting the reaction in the presence of a chlorinating agent of the formula STR3 in which A represents oxygen or the grouping STR4 in which R2 and R3 individually represent alkyl, cycloalkyl or aryl or together represent alkanediyl or oxaalkanediyl and R1 represents hydrogen, chlorine, alkyl, cycloalkyl, aryl or the grouping STR5 in which R2 and R3 have the abovementioned meanings, and where, if R1 represents aryl, A must represent the grouping STR6 in the presence of a basic organic nitrogen compound and in the presence of a diluent at a temperature between about -20° C. and +120° C. The product is known to be useful in the systhesis of pharmaceuticals and insecticides.
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(2008/06/13)

Process for the preparation of substituted 2-chloropyridines
A new process has been found for the preparation of substituted 2-chloropyridine derivatives of the formula (I) STR1 wherein R1 to R4 have the meanings as defined in the description. The new process is characterized in that pyridine 1-oxides of the formula II STR2 are reacted with a chlorine-containing phosphoric acid derivative from the series of the chlorophosphoric esters and chlorophosphoramides in the presence of an inert organic solvent and in the presence of an acid acceptor at temperatures between -20° C. and 200° C., and the resulting product is separated further, if appropriate. Compound (I) is known as an intermediate product for medicaments (cf.DE-A 2,812,585) or for insecticidel nitromethylene derivatives (cf. EP-A 163,855).
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(2008/06/13)

Synthesis of 2-substituted-5-methylpyridines from methylcyclobutanecarbonitrile, valeronitrile and pentenonitrile intermediates
3-Methyl-2-alkylamino-1-halo-1-cyano cyclobutanes are cleaved under acid conditions to form 2-halo-4-formylvaleronitrile and 4-formyl-2-pentenonitrile which can be cyclized to form 2-substituted-5-methylpyridine derivatives. These pyridine derivatives are useful as starting materials in the manufacture of herbicides such as fluazifop-butyl.
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(2008/06/13)

Utilizing Acetyl Hypofluorite for Chlorination, Bromination, and Etherification of the Pyridine System
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
p. 6298 - 6301
(2007/10/02)

Site-Selectivity in the Reaction of 3-Substituted Pyridine 1-Oxides with Phosphoryl Chloride
Site-selectivity in the reaction of 3-substituted pyridine 1-oxide with phosphoryl chloride was investigated.When a strongly electron-withdrawing group (e.g.CN, CONRR', COOR, or NO2) was substituted at the 3-position, the reaction of 3-substituted pyridine 1-oxides with phosphoryl chloride yielded 3-substituted 2-chloropyridines as the main products.Keywords- site-selectivity; 3-substituted pyridine 1-oxide; phosphoryl chloride; 3-substituted 2-chloropyridine; chlorination
Yamanaka, Hiroshi,Araki, Tomio,Sakamoto, Takao
p. 2244 - 2247
(2007/10/02)

Sulphur dehydrogenation process to yield 5-methyl-2-pyridone
A method for synthesizing the aromatic compound 5-methyl-2-pyridone from the corresponding 3,4-dihydro compound by dehydrogenation using sulphur. Particular advantages are achieved by reaction at about 180° C. or less. The product is useful as an intermediate for the preparation of various pyridyloxyphenoxy herbicides.
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(2008/06/13)

2-Piperidones
A method of preparing certain 2-halo-5-methylpyridines, useful as herbicide intermediates, is presented starting from acyclic pentenes. The pentene is difunctionalized, e.g., by making the epoxide, and is then reacted with a nitrogen source to close the ring. The nitrogen-containing 6-membered heterocycle may then be aromatized readily to produce the 2-halo-5-methyl-pyridine desired. Also part of the invention are novel acyclic and cyclic intermediates used in the process.
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(2008/06/13)