Hydrochloric Acid → 6-(Benzyloxy)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid

Temperature

70 °C

To solution of oxalyl chloride (0.6 mL, 6.87 mmol) in anhydrous dichloromethane (15 mL), cooled at −78° C., was added, dropwise, a solution of anhydrous dimethyl sulfoxide (1.2 mL, 16.5 mmol) in dichloromethane (2 mL) and the resulting mixture was stirred for 10 minutes at −78° C. A solution of 2-benzyloxy-1,3-propanediol (0.5 g, 2.75 mmol) in dichloromethane (2 mL) was then added dropwise at −78° C. and the reaction mixture was stirred for 15 minutes. Triethylamine (4.6 mL, 33 mmol) was then added dropwise at −78° C. and the resulting mixture was stirred for 1 hour. The cold bath was removed and an aqueous solution of hydrochloric acid (6 M, 6 mL, 36 mmol) was added, followed by 5-amino-1H-pyrazole-4-carboxylic acid (0.35 g, 2.75 mmol) and the reaction mixture was heated at 70° C. for 1 hour. The solid formed was collected by filtration, washed with water and dried under vacuum. The solid residue (0.53 g) was then washed with dichloromethane to give 65 mg (9% yield) of 6-benzyloxy-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid. MS=270 [M+H]+.

1. additionwas added
2. stirringthe resulting mixture was stirred for 1 hour
3. customThe cold bath was removed
4. customThe solid formed
5. filtrationwas collected by filtration
6. washwashed with water
7. customdried under vacuum
8. washThe solid residue (0.53 g) was then washed with dichloromethane

ORD record

ord-58f21def095b43228af7d24485d7f51f

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09255110B2