Hydrochloric Acid → 4-butyl-2-methyl-5-(pyridin-2-ylmethyl)-1H-pyrazolo[4,3-c]pyridine-3,6(2H,5H)-dione

HRID 1471443Notes

Reaction equation

HRID 1471443 reaction equation
[Na].[CH3:2][N:3]1[C:7](=[O:8])/[C:6](=[C:9](\[NH:14][CH2:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=2)/[CH2:10][CH2:11][CH2:12][CH3:13])/[C:5]([CH2:22][C:23]([O:25]C)=O)=[N:4]1.Cl>CC(O)C>[CH2:10]([C:9]1[N:14]([CH2:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=2)[C:23](=[O:25])[CH:22]=[C:5]2[NH:4][N:3]([CH3:2])[C:7](=[O:8])[C:6]=12)[CH2:11][CH2:12][CH3:13]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 5360545SodiumHCID 178446324HCID 178446324, compound

Product 1

HCID 583581144-butyl-2-methyl-5-(pyridin-2-ylmethyl)-1H-pyrazolo[4,3-c]pyridine-3,6(2H,5H)-dioneYield 80%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Procedure

An isopropanolic solution of i-PrONa, obtained by dissolving of sodium (0.082 g, 3.57 mmol, 1 equiv.) in i-PrOH (75 ml), was treated with methyl [(4Z)-1-methyl-5-oxo-4-{1-[(pyridin-2-ylmethyl)amino]pentylidene}-4,5-dihydro-1H-pyrazol-3-yl]acetate (Compound of Formula (VIII) (0.61 g, 3.57 mmol, 1 equiv.). The reaction mixture was refluxed for 1 h, then cooled and neutralized to pH 7 by addition of 0.59 ml of a 20% aqueous HCl solution. 50 ml of i -PrOH were removed in vacuo and 25 ml of H2O were added before placing the flask in the fridge overnight. The white precipitate formed was filtered off, washed with water (2×5 ml), then with cyclohexane and dried in vacuo. 0.88 g of pure product 4-butyl-2-methyl-5-(pyridin-2-ylmethyl)-1H-pyrazolo[4,3-c]pyridine-3,6(2H,5H)-dione was obtained. Yield 80%. 1HNMR ( DMSO-d6, 400 MHz): 0.80 (3H, t, J=7.2 Hz); 1.29-1.35 (2H, m); 1.38-1.43 (2H, m); 3.19 (3H, s); 3.22-3.24 (2H, m); 5.49 (2H, s); 5.72 (1H, s); 7.42 (1H, d, J=8 Hz); 7.62 (1H, t, J=6.6 Hz); 8.12 (1H, t, J=8 Hz); 8.65 (1H, d, J=5.2 Hz). MS (ESI+): 313.4; MS (ESI−): 311.3.

Workup

  1. temperatureThe reaction mixture was refluxed for 1 h
  2. temperaturecooled
  3. custom50 ml of i -PrOH were removed in vacuo and 25 ml of H2O
  4. additionwere added
  5. customin the fridge overnight
  6. customThe white precipitate formed
  7. filtrationwas filtered off
  8. washwashed with water (2×5 ml)
  9. dry with materialwith cyclohexane and dried in vacuo

Sources & evidence

ORD record
ord-3cf4b7086bbb4701a4196e9fa71f5f79
Source dataset
uspto-grants-2015_04
Patent number
US09012449B2

Reaction notes

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