摘要:
Provided is a method of preparing and recovering 2-methyl-5-iodobenzoic acid. The method utilizes o-methylbenzoic acid as raw material, iodinating via iodine/potassium persulfate in a mixed acid solvent to obtain a mixture of 2-methyl-5-iodobenzoic acid, 2-methyl-3-iodobenzoic acid, and 2-methyl-3, 5-diiodobenzoic acid; refining to obtain 2-methyl-5-iodobenzoic acid and recoverable mother liquor, the recoverable mother liquor being a mixture of 2-methyl-5-iodobenzoic acid, 2-methyl-3-iodobenzoic acid, and 2-methyl-3, 5-diiodobenzoic acid; conducting catalytic hydrogenation and deiodination to recover o-methylbenzoic acid and iodide ions; and oxidating the iodide ions to recover iodine. The whole process is recycled. The preparation and recovery method has cheap and easily available raw materials, and is easy of operation, has low requirements for equipment, and is suitable for large-scale industrial production.
摘要:
Provided is a method of preparing and recovering 2-methyl-5-iodobenzoic acid. The method utilizes o-methylbenzoic acid as raw material, iodinating via iodine/potassium persulfate in a mixed acid solvent to obtain a mixture of 2-methyl-5-iodobenzoic acid, 2-methyl-3-iodobenzoic acid, and 2-methyl-3, 5-diiodobenzoic acid; refining to obtain 2-methyl-5-iodobenzoic acid and recoverable mother liquor, the recoverable mother liquor being a mixture of 2-methyl-5-iodobenzoic acid, 2-methyl-3-iodobenzoic acid, and 2-methyl-3, 5-diiodobenzoic acid; conducting catalytic hydrogenation and deiodination to recover o-methylbenzoic acid and iodide ions; and oxidating the iodide ions to recover iodine. The whole process is recycled. The preparation and recovery method has cheap and easily available raw materials, and is easy of operation, has low requirements for equipment, and is suitable for large-scale industrial production.
摘要:
The present invention relates to a method for recycling chiral 1-benzyl-3-hydroxypiperidine by racemization, which particularly comprises using resolution-recycled chiral N-benzyl-3-hydroxypiperidine (I) as a raw material, and recycling by racemization under the effect of a strong base to obtain N-benzyl-3-hydroxypiperidine. The recycling scheme by racemization has not been reported in literature, has a simple reaction, and is suitable for mass industrial production.
摘要:
The Invention discloses a method for preparing a Dabigatran etexilate intermediate. The process of the method is as follows: a) taking 3-amino-4-methylamino benzoic acid as the raw material, synthesizing 2-methyl chloride-1-methyl-1H-benzimidazole-5-carboxylic acid through cyclization reaction with chloroacetyl chloride; b) the 2-methyl chloride-1-methyl-1H-benzimidazole-5-carboxylic acid generates 2-methyl chloride-1-methyl-1H-benzimidazole-5 formyl chloride under the action of oxalyl chloride; c) the 2-methyl chloride-1-methyl-1H-benzimidazole-5-formyl chloride generates N-(2-methyl chloride-1-methyl-1H-benzimidazole-5-acyl)-N-(pyridine-2-yl)-3-aminopropionic acid ethyl ester through condensation reaction with 3-(pyridine-2-yl) aminopropionic acid ethyl ester. The synthetic route has not been reported ever before; moreover, with cheap and widely available raw materials, simple unit operation and low requirement for equipment, the method is suitable for industrialized mass production.
摘要:
The present invention relates to a method of preparation and chiral inversion of chiral-1-t-butoxycarbonyl-3-hydroxy piperidine, the method mainly comprising the steps of: using N-benzyl-3-hydroxy piperidine as raw material, and splitting to obtain (S) or (R)-1-benzyl-3-hydroxy piperidine camsylate; dissociating by a base to obtain (S) or (R)-1-benzyl-3-hydroxy piperidine; conducting hydrogenating debenzylation/t-butoxycarbonyl protection by palladium-charcoal to obtain (S) or (R)-1-t-butoxycarbonyl-3-hydroxy piperidine. Using (R) or (S)-1-substituted-3-hydroxy piperidine as raw material, and acylating the substituted sulfonyl chloride to obtain (R) or (S)-1-substituted-3-hydroxy piperidine sulfonic ester; substituting in substitute carboxylates to obtain (S) or (R)-1-substituted-3-hydroxy piperidine carboxylic ester; hydrolyzing by base to obtain (S) or (R)-1-substituted-3-hydroxy piperidine. The synthesis route has mild reaction conditions, and is suitable for industrial mass production.
摘要:
Disclosed is an N-substituted phenyl glycine (dabigatran etexilate intermediate) preparation method unreported in any document, the method comprising: utilizing cheap and easily available substituted aniline (1) as raw material to condense with glyoxylic acid to form an imine, while conducting hydrogenation reduction to obtain N-(substituted phenyl) glycine. The synthetic route is not reported in any document, and the raw material is cheap and easily available; in addition, the present invention has simple unit operation and low device requirement, and is suitable for large-scale industrial production.
摘要:
Disclosed is a 2-substituted-2H-1,2,3-triazole derivative, a compound as represented by formula I or II. Also disclosed is a preparation method of the compound as represented by formula I or II, in particular to a preparation method of 2-substituted-4-bromo-5-chloro-1H-1,2,3-triazole, 2-substituted-4-bromo-5-iodo-1H-1,2,3-triazole, and 2-substituted-5-chloro-1H-1,2,3-triazole-4-carboxylic acid. The preparation methods of the present invention are simple and feasible, and has high yield of the obtained compounds.