2-Methylpyrazolo[1,5-a]pyriMidine-6-carboxylic acid synthesis
- Product Name:2-Methylpyrazolo[1,5-a]pyriMidine-6-carboxylic acid
- CAS Number:739364-95-5
- Molecular formula:C8H7N3O2
- Molecular Weight:177.16
![2-methylpyrazolo[1,5-a]pyrimidine-6-carboxylic acid amide](/CAS/20180703/GIF/338953-49-4.gif)
338953-49-4
739364-95-5
The general procedure for the synthesis of 2-methylpyrazolo[1,5-a]pyrimidine-6-carboxylic acid, using the compound (CAS: 338953-49-4) as a starting material, was as follows (Intermediate Example 16): 2-methylpyrazolo[1,5-a]pyrimidine-6-carboxylic acid amide (475 mg) was dissolved in ethanol (5 mL), and a 5 N sodium hydroxide solution was subsequently added to the solution (2 mL). The reaction mixture was stirred at 70 °C for 1 hour. After completion of the reaction, the mixture was cooled to room temperature, an appropriate amount of water was added and the reaction mixture was washed with ethyl acetate. After separating the aqueous phase, 2 N hydrochloric acid was added dropwise until the pH became acidic. The precipitated white crystals were collected by filtration and washed sequentially with water and hexane. Finally, the resulting crystals were dried under reduced pressure to afford the target product 2-methylpyrazolo[1,5-a]pyrimidine-6-carboxylic acid (300 mg, yield: 63%). Product mass spectral data: ESI/MS m/z 178 ([M+H]+), 176 ([M-H]-).
![2-methylpyrazolo[1,5-a]pyrimidine-6-carbaldehyde](/CAS/20210111/GIF/933692-37-6.gif)
933692-37-6
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739364-95-5
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Yield:739364-95-5 76.7%
Reaction Conditions:
with sodium chlorite;dihydrogen peroxide in water at 50; for 1 h;Reagent/catalyst;Temperature;Solvent;
Steps:
10-14 Preparation of 2-methyl-pyrazolo[1,5-a]pyrimidine-6-carboxylic acid (VI)
Add 100 ml of water to a 500 mL four-necked flask equipped with a mechanical stirrer and a thermometer.6-carbaldehyde-2-methyl-pyrazolo[1,5-a]pyrimidine (V)35.2g (0.22mol),30% hydrogen peroxide 41.9g (0.33mol), sodium chlorite 29.9g (0.33mol),The temperature was raised to 50 ° C for 1 hour, and the temperature was lowered to 20 ° C. TLC showed the reaction was complete.Adjust to the starch potassium iodide reagent with sodium sulfite without discoloration, adjust the pH to 2 to 3 with hydrochloric acid.Filtered, the solid was recrystallized from 200 ml of ethanol.Obtained 29.8 g of 2-methyl-pyrazolo[1,5-a]pyrimidine-6-carboxylic acid (VI) as a white solid.The yield was 76.7%.In the present embodiment, the amount of hydrogen peroxide is the molar amount of the compound V: 150%.In the present embodiment, the amount of sodium chlorite used is the molar amount of the compound V: 150%.
References:
Hangzhou Hankang Bio-pharmaceutical Technology Co., Ltd.;Xiong Yi;Liu Ya CN110003218, 2019, A Location in patent:Paragraph 0069-0096
338953-49-4
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739364-95-5
239 suppliers
$7.00/250mg