Methanesulfonic Acid → 1-cyclopentyl-3-methyl-6-(2-propoxyphenyl)-2H-pyrazolo[3,4-d]pyrimidin-4-one

HRID 619140Notes

Reaction equation

HRID 619140 reaction equation
[CH:1]1([N:6]2[C:10]([NH2:11])=[C:9]([C:12]([NH2:14])=[O:13])[C:8]([CH3:15])=[N:7]2)[CH2:5][CH2:4][CH2:3][CH2:2]1.[CH2:16]([O:19][C:20]1[CH:27]=[CH:26][CH:25]=[CH:24][C:21]=1[CH:22]=O)[CH2:17][CH3:18].CS(O)(=O)=O>O>[CH:1]1([N:6]2[C:10]3=[N:11][C:22]([C:21]4[CH:24]=[CH:25][CH:26]=[CH:27][C:20]=4[O:19][CH2:16][CH2:17][CH3:18])=[N:14][C:12](=[O:13])[C:9]3=[C:8]([CH3:15])[NH:7]2)[CH2:2][CH2:3][CH2:4][CH2:5]1

Participants

5

Conditions

Temperature
180 °C

Procedure

A mixture of 1-cyclopentyl-3-methyl-5-amino-1H-pyrazole-4-carboxamide (3.98 g, 0.019 mol), 2-propoxybenzaldehyde (6.35 g, 0.038 mol), xylenes (150 ml) and methanesulfonic acid (0.5 ml) was heated at reflux for 39 hours with azeotropic removal of water. The reaction mixture was concentrated in vacuo and the residue was treated with 10% K2CO3 and ether. The layers were separated, the aqueous layer was extracted with ether and the combined ether layers were concentrated in vacuo. Analysis of the reaction mixture by TLC indicated that the reaction was not yet complete, therefore, the mixture was heated at 180° C. on an oil bath. The residue was dissolved in chloroform, and purified by column chromatography on silica gel eluting with hexane (100%) followed by ether (100%) to afford 2.67 g (41%) of 1-cyclopentyl-3-methyl-6-(2-propoxyphenyl)-pyrazolo[3,4-d]pyrimidin-4-one, m.p. 130-132° C.

Workup

  1. temperaturewas heated
  2. concentrationThe reaction mixture was concentrated in vacuo
  3. additionthe residue was treated with 10% K2CO3 and ether
  4. customThe layers were separated
  5. extractionthe aqueous layer was extracted with ether
  6. concentrationthe combined ether layers were concentrated in vacuo
  7. dissolutionThe residue was dissolved in chloroform
  8. custompurified by column chromatography on silica gel eluting with hexane (100%)

Sources & evidence

ORD record
ord-307fc7f3c7804ec7bf296d10da9f426e
Source dataset
uspto-grants-1999_09
Patent number
US05958929

Reaction notes

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