7499-08-3Relevant articles and documents
Preparation method for 2-methyl-3-methoxybenzoic acid and preparation method for intermediate thereof
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Paragraph 0040-0041; 0044; 0047; 0050; 0052, (2017/08/31)
The invention discloses a preparation method for 2-methyl-3-methoxybenzoic acid and a preparation method for an intermediate thereof. The preparation method for the intermediate namely 2-methyl-3-chlorobenzoic acid comprises the following steps: introducing oxygen into a mixed solution of a C2-6 organic acid, a catalyst and 3-chloro-ortho-xylene, and carrying out a reaction, wherein the catalyst is a cobalt-manganese-bromine composite catalyst or a cobalt-bromine composite catalyst; the reaction temperature is 100 to 210 DEG C; the reaction pressure is 0.1 to 3 MPa; and the introduction time of the oxygen is 1 to 12 h. The preparation method provided by the invention uses 3-chloro-ortho-xylene as a starting material, has the advantages of simple and convenient process, short production period, high yield, clean production and reduced cost, and is applicable to industrial production.
PROCESS FOR PRODUCTION OF IODINE COMPOUNDS AND PROCESS FOR PRODUCTION OF HIGH-PURITY 5-IODO-2-METHYLBENZOIC ACID
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Page/Page column 11-12, (2008/06/13)
Provided is a production method for an iodine compound in which iodine is reacted with a substrate in the presence of a porous material having a pore diameter of 500 nm or less or in the presence of the above porous material and an oxidizing agent and a production process for high purity 5-iodo-2-methylbenzoic acid comprising an iodination reaction step carried out by the above-mentioned, a crystal precipitation and separation step in which a product is precipitated by adding water or cooling and then separated and a purification step in which crystal separated is recrystallized using an organic solvent. According to the production method for an iodine compound described above, iodine can be introduced into various substrates at a high selectivity. Since expensive metals and specific reagents do not have to be used, it can readily be carried out in an industrially scale, and the product having a high purity can be obtained. Further, the process comprising the iodination reaction, separation and purification steps described above makes it possible to readily obtain at a high yield, 5-iodo-2-methylbenzoic acid having a high purity which is useful in uses for functional chemical products such as medicines. The process of the present invention comprising iodination reaction, separation and purification steps is characterized by that it is simple in terms of a procedure and that the purification load is smaller, and it is very advantageous in industrially carrying out.
Directed lithiation of unprotected benzoic acids
Bennetau, Bernard,Mortier, Jacques,Moyroud, Joel,Guesnet, Jean-Luc
, p. 1265 - 1272 (2007/10/02)
Benzoic acid gives the ortho-lithiated species 1 under standard conditions (s-BuLi-TMEDA-THF, -90 deg C).Reaction of 1 at -78 deg C with either methyl iodide, dimethyl disulfide, hexachloroethane, or 1,2-dibromotetrachloroethane gives the ortho-substituted product.Intramolecular competition between the carboxylic acid and methoxy, chloro, fluoro, or diethylamido functions in ortho- and -para-substituted benzoic acids establishes the carboxylic acid group to be of intermediate capacity in directing metallation.Complimentarity of directing effects is observed with the chloro and fluoro groups in the meta-substituted benzoic acid but not with the methoxy and trifluoromethyl groups.Electrophile introduction into meta- and para-lithiated benzoates occurs with equal efficacy and comparable scope.The 2,4-dihalogenobenzoic acids undergo hydrogen/metal exchange at the position flanked by both halogen substituents. 2,2-Difluoro-1,3-benzodioxole-4-carboxylic acid undergoes lithiation adjacent to the oxygen atom.By use of such methods, routes to benzoic acids contiguously tri- and tetra-substituted with a variety of functionalities have been developed.
