5-Chloropyrazolo[1,5-a]pyrimidine synthesis
- Product Name:5-Chloropyrazolo[1,5-a]pyrimidine
- CAS Number:29274-24-6
- Molecular formula:C6H4ClN3
- Molecular Weight:153.57
![5-Hydroxypyrazolo[1,5-a]pyrimidine](/CAS/GIF/29274-22-4.gif)
29274-22-4
29274-24-6
General procedure for the synthesis of 5-chloropyrazolo[1,5-a]pyrimidin-5-ol from pyrazolo[1,5-a]pyrimidin-5-ol: Pyrazolo[1,5-a]pyrimidin-5-ol (17.0 g, 126 mmol) was dissolved in phosphorus triclosan (100 mL) and heated to reflux for 3 hours. Upon completion of the reaction, the reaction was cooled to room temperature and the reaction mixture was concentrated under reduced pressure to remove excess phosphorous trichloride. Dichloromethane (100 mL) was added to the residue to dissolve it, followed by careful washing of the organic phase with saturated aqueous sodium bicarbonate solution (100 mL x 3) to neutralize acidic impurities. The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. The crude product was purified by short silica gel column chromatography, using 50% ethyl acetate in hexane solution as eluent, the target fraction was collected and concentrated under reduced pressure to give 5-chloropyrazolo[1,5-a]pyrimidine (13.1 g, 68% yield).
29274-22-4
142 suppliers
$9.00/100mg
29274-24-6
241 suppliers
$9.00/250mg
Yield:29274-24-6 88%
Reaction Conditions:
with trichlorophosphate in acetonitrile at 85; for 2 h;Large scale;
Steps:
2
n the second step, 1 kg of the compound C is dissolved in 2 kg of acetonitrile, and 400 g of phosphorus oxychloride is slowly added to the acetonitrile solution of the compound C under anhydrous oxygen-free and nitrogen-free protection, heated to 85 ° C, and refluxed for 2 hours. Clarification, the solvent was evaporated under reduced pressure to give a yellow solid, and 1 kg of water was slowly added to the yellow solid to remove a small amount of residual thionyl chloride, and filtered to obtain 1 kg of a yellow solid compound D in a yield of 88%
References:
Shanghai Lingkai Pharmaceutical Technology Co., Ltd.;Lu Qian;Kuang Yi;Cui Xiaozhan CN109251205, 2019, A Location in patent:Paragraph 0025; 0026; 0029
29274-22-4
142 suppliers
$9.00/100mg
29274-24-6
241 suppliers
$9.00/250mg
![5-BROMOPYRAZOLO[1,5-A]PYRIMIDINE](/CAS2/GIF/1159981-95-9.gif)
1159981-95-9
73 suppliers
$28.00/100mg
29274-24-6
241 suppliers
$9.00/250mg