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

HRID 1773590Notes

Reaction equation

HRID 1773590 reaction equation
[NH2:1][C:2]1[NH:6][N:5]=[CH:4][C:3]=1[C:7]([OH:9])=[O:8].C(O[CH:13](OCC)[CH:14]([CH3:22])[CH:15](OCC)OCC)C.Cl>>[CH3:22][C:14]1[CH:13]=[N:1][C:2]2[N:6]([N:5]=[CH:4][C:3]=2[C:7]([OH:9])=[O:8])[CH:15]=1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 827611,1,3,3-Tetraethoxy-2-methylpropaneHCID 967743-amino-1H-pyrazole-4-carboxylic acid

Product 1

HCID 64854106-Methylpyrazolo[1,5-a]pyrimidine-3-carboxylic acidYield 81%

Conditions

Temperature
95 °C

Procedure

A suspension of 5-amino-1H-pyrazole-4-carboxylic acid (271 mg, 2.1 mmol) and 1,1,3,3-tetraethoxy-2-methyl-propane (prepared accordingly to the procedure described in JACS126(7), 2004, 2194) (0.5 g, 2.1 mmol) in an aqueous solution of hydrochloric acid (6 M, 1.3 mL) was heated at 95° C. in a sealed tube. The solid material completely dissolved when the temperature reached 82° C. and then a solid precipitate crushed out of solution, stirring was continued for 5 minutes. The resulting mixture was cooled to room temperature and the solid was collected by filtration, rinsed with water and dried in vacuum oven to afford 305.1 mg (81% yield) of 6-methyl-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid.

Workup

  1. customprepared accordingly to the procedure
  2. dissolutionThe solid material completely dissolved when the temperature
  3. customreached 82° C.
  4. customa solid precipitate crushed out of solution
  5. temperatureThe resulting mixture was cooled to room temperature
  6. filtrationthe solid was collected by filtration
  7. washrinsed with water
  8. customdried in vacuum oven

Sources & evidence

ORD record
ord-5bfa95893100493b97ffbf85968a7e13
Source dataset
uspto-grants-2016_02
Patent number
US09255110B2

Reaction notes

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