Hydrochloric Acid → 6-Methoxypyrazolo[1,5-a]pyrimidine-3-carboxylic acid

To a solution of oxalyl chloride (6.9 mL) in dichloromethane (65 mL), cooled at −78° C., was added, dropwise, a solution of dimethyl sulfoxide (13 mL) in dichloromethane (16 mL) and the resulting mixture was stirred for 10 minutes. A solution of 2-O-methyl-glycerol (3.3 g, 31.5 mmol) in dichloromethane (16 mL) was then added dropwise and the reaction mixture was stirred for 15 minutes. Triethylamine (52 mL) was then added dropwise and the resulting mixture was stirred for 1 hour. The reaction mixture was warmed up to room temperature and an aqueous solution of hydrochloric acid (6 M, 35 mL) was added followed by 5-amino-1H-pyrazole-4-carboxylic acid (4 g, 31.5 mmol) and the resulting mixture was heated to 95° C. over 20 minutes, the temperature was maintained at 95° C. for 20 minutes. The resulting mixture was cooled to room temperature and stored at room temperature for 24 hours and at 4° C. for 62 hours. The solid formed was collected by filtration and dried in a vacuum oven to afford 1.087 g (18% yield) of 6-methoxy-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid.

1. additionwas added
2. stirringthe resulting mixture was stirred for 1 hour
3. temperaturethe resulting mixture was heated to 95° C. over 20 minutes
4. temperaturethe temperature was maintained at 95° C. for 20 minutes
5. temperatureThe resulting mixture was cooled to room temperature
6. waitstored at room temperature for 24 hours and at 4° C. for 62 hours
7. customThe solid formed
8. filtrationwas collected by filtration
9. customdried in a vacuum oven

ORD record

ord-cdf4ef7ba91f4c3894e9fc4e231e263e

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09255110B2