Acetic Acid → 3-(Propan-2-yl)-2H-pyrazolo[4,3-d]pyrimidine-5,7(4H,6H)-dione

HRID 19591Notes

Reaction equation

HRID 19591 reaction equation
[NH2:1][C:2]1[C:3]([C:10]([NH2:12])=[O:11])=[N:4][NH:5][C:6]=1[CH:7]([CH3:9])[CH3:8].N[C:14](N)=[O:15].C(O)(=O)C>[OH-].[Na+]>[OH:15][C:14]1[N:12]=[C:10]([OH:11])[C:3]2[NH:4][N:5]=[C:6]([CH:7]([CH3:9])[CH3:8])[C:2]=2[N:1]=1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 1176UreaHCID 160997494-amino-3-(propan-2-yl)-1H-pyrazole-5-carboxamide

Product 1

HCID 1784404203-(Propan-2-yl)-2H-pyrazolo[4,3-d]pyrimidine-5,7(4H,6H)-dioneYield 78.5%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
5 °C

Procedure

Mixture of 4-amino-5-isopropylpyrazole-3-carboxamide (770 mg, 4.58 mmol) and urea (1.4 g, 4.58 mmol) was fused at 180° C. for 30 min. After cooling, the solid was dissolved in 2.3 mL of 2 M sodium hydroxide. The boiling solution was acidified with glacial acetic acid and the warm solution was filtered. This solution was cooled to 5° C. and the product started to precipitate after a few minutes. The crude product (1.3 g) was recrystallized twice from a hot water. Yield 78.5%; mp=295-298° C. 1H NMR (300 MHz, DMSO): 1.21 d (6H, J=6.6 Hz), 3.17 sept (1H, J=6.6 Hz). MS (EI): 194(94; C8H10N4O2); 179(100; C7H7N4O2); 162(51; C7H4N3O2); 136(15); 123(7); 95(8); 81(13); 54(26); 43(23).

Workup

  1. temperatureAfter cooling
  2. filtrationthe warm solution was filtered
  3. customto precipitate after a few minutes
  4. customThe crude product (1.3 g) was recrystallized twice from a hot water

Sources & evidence

ORD record
ord-5cc9270c27414428b671ab4cd3136f87
Source dataset
uspto-grants-2010_06
Patent number
US07745450B2

Reaction notes

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