Sodium Hydroxide → 4,9-Dihydro-4-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxylic Acid

HRID 443851Notes

Reaction equation

HRID 443851 reaction equation
[CH3:1][N:2]1[C:11]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[C:5](=[O:12])[N:4]2[N:13]=[C:14]([C:16]([O:18]CC)=[O:17])[CH:15]=[C:3]12.[OH-].[Na+]>CO>[CH3:1][N:2]1[C:11]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[C:5](=[O:12])[N:4]2[N:13]=[C:14]([C:16]([OH:18])=[O:17])[CH:15]=[C:3]12

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 125525054,9-Dihydro-4-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxylic acid, ethyl ester

Product 1

HCID 127132494,9-Dihydro-4-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxylic Acid

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 5.8 g of 4,9-dihydro-4-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxylic acid, ethyl ester, 50 ml of 1 N aqueous sodium hydroxide and 400 ml of methanol is heated at reflux until complete solution is attained (about 30 minutes). The solution is evaporated at reduced pressure to remove methanol; the residue is diluted with water and acidified with 1 N hydrochloric acid. The resulting precipitate is 4,9-dihydro-4-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxylic acid is collected by filtration, washed with water and dried; mp 265° C., after crystallization from dimethylformamide/methanol.

Workup

  1. temperatureis heated
  2. temperatureat reflux until complete solution
  3. custom(about 30 minutes)
  4. customThe solution is evaporated at reduced pressure
  5. customto remove methanol
  6. additionthe residue is diluted with water
  7. filtrationis collected by filtration
  8. washwashed with water
  9. customdried
  10. custommp 265° C., after crystallization from dimethylformamide/methanol

Sources & evidence

ORD record
ord-c3775460aa7549e6b528de6502790255
Source dataset
uspto-grants-1981_04
Patent number
US04261997

Reaction notes

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