Some tips on 1,3-Dimethyl-1H-pyrazol-5-ol

The synthetic route of 1,3-Dimethyl-1H-pyrazol-5-ol has been constantly updated, and we look forward to future research findings.

These common heterocyclic compound, 5203-77-0, name is 1,3-Dimethyl-1H-pyrazol-5-ol, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. COA of Formula: C5H8N2O

3-(2-Methoxyethoxy)-2-methyl-4-(methylsulfonyl)benzoic acid (1 g) was dissolved in chloroform (20 mL), and oxalyl chloride (500 mg) was added. A catalytic amount of dimethylformamide was added, followed by stirring at room temperature for 3 hours. Then, the solvent was distilled off under reduced pressure. The obtained residue was dissolved in tetrahydrofuran (5 mL), and then a solution having 5-hydroxy-1 ,3-dimethylpyrazole (450 mg) dissolved in tetrahydrofuran (15 mL) was slowly added. Triethylamine (0.65 mL) was added, followed by heating and refluxing for 5 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and poured into water, then acidified with dilute hydrochloric acid and then extracted with ethyl acetate. The organic layer was washed with a saturated sodium chloride aqueous solution and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure. The obtained residue was dissolved in acetonitrile (20 mL), and under cooling in an ice bath, triethylamine (0.65 mL) and acetone cyanohydrin (100 mg) were added, followed by stirring at room temperature for 18 hours. The reaction solution was poured into water and washed with a small amount of ethyl acetate. Then, the aqueous layer was acidified with dilute hydrochloric acid. It was extracted with ethyl acetate, and then, the organic layer was washed with a saturated sodium chloride aqueous solution and then dried over magnesium sulfate. The solvent was distilled off 5 under reduced pressure. The obtained residue was purified by column chromatography (developing solvent: ethyl acetate) to obtain 5-hydroxy-1 ,3-dimethylpyrazol-4-yl 3-(2- methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl ketone (500 mg, the following Compound No. 5- 2) as slightly yellow solid.

The synthetic route of 1,3-Dimethyl-1H-pyrazol-5-ol has been constantly updated, and we look forward to future research findings.