591-97-9Relevant academic research and scientific papers
Method for preparing 2-chloro-5-substituted pyridine
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Paragraph 0015; 0061-0064; 0065; 0068, (2021/09/21)
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.
METHOD OF CONVERTING ALCOHOL TO HALIDE
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Page/Page column 53; 110, (2017/01/02)
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
Catalytic phosphorus(V)-mediated nucleophilic substitution reactions: Development of a catalytic appel reaction
Denton, Ross M.,An, Jie,Adeniran, Beatrice,Blake, Alexander J.,Lewis, William,Poulton, Andrew M.
experimental part, p. 6749 - 6767 (2011/10/02)
Catalytic phosphorus(V)-mediated chlorination and bromination reactions of alcohols have been developed. The new reactions constitute a catalytic version of the classical Appel halogenation reaction. In these new reactions oxalyl chloride is used as a consumable stoichiometric reagent to generate the halophosphonium salts responsible for halogenation from catalytic phosphine oxides. Thus, phosphine oxides have been transformed from stoichiometric waste products into catalysts and a new concept for catalytic phosphorus-based activation and nucleophilic substitution of alcohols has been validated. The present study has focused on a full exploration of the scope and limitations of phosphine oxide catalyzed chlorination reactions as well as the development of the analogous bromination reactions. Further mechanistic studies, including density functional theory calculations on proposed intermediates of the catalytic cycle, are consistent with a catalytic cycle involving halo- and alkoxyphosphonium salts as intermediates.
Phosphine oxide-catalysed chlorination reactions of alcohols under Appel conditions
Denton, Ross M.,An, Jie,Adeniran, Beatrice
supporting information; experimental part, p. 3025 - 3027 (2010/08/04)
A phosphine oxide-catalysed chlorination reaction of primary and secondary alcohols has been developed. This process represents the first triphenylphosphine oxide-catalysed alcohol chlorination under Appel conditions. The Royal Society of Chemistry 2010.
Ruthenium catalyzed enyne cycloisomerizations and hydroxycyclizations with skeletal rearrangement
Faller,Fontaine, Philip P.
, p. 1912 - 1918 (2007/10/03)
A neutral arene-tethered ruthenium complex was found to be a catalyst precursor for enyne cycloisomerizations and hydroxycyclizations. The observed products were the result of a skeletal rearrangement process, and include an unusual cyclization to form a six-membered ring. Labeling studies on the six-membered ring product are in accord with an electrophilic activation mechanism that proceeds via cationic cyclopropyl carbene intermediates.
Reactivity of bismuth(III) halides towards alcohols. A tentative to mechanistic investigation
Keramane, El Mehdi,Boyer, Bernard,Roque, Jean-Pierre
, p. 1909 - 1916 (2007/10/03)
The reactivity of bismuth(III) halides (BiX3; X=Cl, Br and I) towards a series of alcohols has been investigated. Three different reactions have been studied, namely: halogenation, dehydration and etherification. The behaviour of these bismuth derivatives was found to depend on the nature of the halide bonded to the bismuth atom. Their reactivities can be interpreted on the basis of the Hard and Soft Acids and Bases (HSAB) principle. A mechanism is proposed which involves the formation of a complex of the alcohol with Bi(III).
TRANSITION METHAL-CATALYZED SUBSTITUTION REACTION OF ALLYLIC PHOSPHATES WITH GRIGNARD REAGENTS
Yanagisawa, Akira,Nomura, Nobuyoshi,Yamamoto, Hisashi
, p. 6017 - 6028 (2007/10/02)
SN2-selective Grignard coupling with primary allylic diphenylphosphates was successfully achieved using Ni or Fe catalyst.In sharp contrast, a catalytic amount of CuCN*2LiCl promoted a SN2'-selective coupling reaction.In the presence of the copper catalyst, stereochemically homogeneous γ-disubstituted allyl Grignard reagents reacted at the less substituted allylic terminus (α-position) with an allylic diphenylphosphate selectively without losing the double bond geometry.
