55289-06-0Relevant articles and documents
Synthesis process 2 - methyl -3 - methoxybenzoic acid
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Paragraph 0024; 0029; 0045-0046; 0052-0053; 0059; 0062, (2021/10/20)
The invention discloses a synthesis process of 2 - methyl -3 - methoxybenzoic acid, which comprises the following steps: (1) reducing hydrogenation reaction: taking 2 - methyl -3 - nitrobenzoic acid or 2 - methyl -3 - nitrobenzoate as raw materials and methanol as a solvent. The hydrogen is a hydrogen source, and palladium carbon or platinum carbon is used as a catalyst to prepare 3 - amino -2 - methyl benzoic acid or 3 - amino -2 - methyl benzoic acid methyl ester by hydrogenation reduction. (2) Diazotization and hydrolysis and esterification one-pot reaction: preparing and hydroxyl 3 - methyl benzoic acid methyl ester by carrying out diazotization and hydrolysis -2 - esterification reaction under the action of a reducing product as a raw material and methanol as a solvent and a diazotization reagent. (3) Methylation reaction: methyl benzoate serving 3 - hydroxyl -2 - is used as a raw material, dimethyl sulfate is used as a methylation reagent, and methyl benzoate is produced 3 - methoxy -2 - methyl benzoate in the presence of a base. (4) Hydrolysis Reaction: methyl 3 - methoxy -2 - methyl benzoate and base. Water is mixed, heated and hydrolyzed, the reaction is complete, the product precipitated by acid conditioning PH through 1-3, filtered, and dried to obtain 3 - methoxy -2 -methylbenzoic acid.
2-methyl-3-methoxybenzoic acid and preparation method thereof
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Paragraph 0034; 0036-0038; 0040-0043; 0044-0046; 0048-0050, (2020/05/01)
The invention belongs to the field of compound synthesis, and discloses 2-methyl-3-methoxybenzoic acid and a preparation method thereof, wherein the 2-methyl-3-methoxybenzoic acid is prepared from thefollowing raw materials: 2-methyl-3-chloroanisole, methylbenzene, tetrahydrofuran, magnesium chips, an initiator and a carboxylating agent. According to the invention, the preparation method solves the problems of large pollution hazard, high cost and low yield in the existing 2-methyl-3-methoxybenzoic acid preparation method; and the yield of the intermediate 2-methyl-3-chloroanisole of 2-methyl-3-methoxybenzoic acid obtained in the preparation method can reach 90-91%, the yield of 2-methyl-3-methoxybenzoic acid prepared from 2-methyl-3-chloroanisole is about 88%, the reaction is easy to control, the pollution is small, and the cost is low.
Preparation method of 2-methyl-3-methoxybenzoic acid
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Paragraph 0021, (2018/03/24)
The invention relates to a preparation method of 2-methyl-3-methoxybenzoic acid. The preparation method comprises the following specific steps: A, adding a proper amount of a sodium methoxide solution, 2,6-dichlorotoluene, dimethylformamide and cuprous salt into a reaction kettle; stirring and raising the temperature; controlling the temperature to 80 DEG C to 150 DEG C and reacting to obtain 2-methyl-3-chloroanisole; B, adding a proper amount of tetrahydrofuran and magnesium into the other reaction kettle; controlling the temperature to be 30 DEG C to 60 DEG C; adding a mixed solution of bromoethane and the 2-methyl-3-chloroanisole; after reacting for 20min to 40min, controlling the temperature to be 40 DEG C to 60 DEG C and dropwise adding the 2-methyl-3-chloroanisole; after dropwise adding, keeping heat and reacting for 1.5h to 2.5h; then cooling to -15 DEG C to -5 DEG C; adding dry ice by batches; controlling the temperature to be 0 DEG C to 20 DEG C, keeping the heat and reactingfor 2h to 4h; then recycling the tetrahydrofuran; adjusting the pH (Potential of Hydrogen) value to separate out white powder, namely the 2-methyl-3-methoxybenzoic acid. The preparation method of the2-methyl-3-methoxybenzoic acid, provided by the invention, is simple in route and high in yield.
