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

HRID 1253450Notes

Reaction equation

HRID 1253450 reaction equation
[Na].C[O:3][C:4](=O)[CH2:5][C:6]1=[N:7][N:8]([CH3:25])[C:9](=[O:24])/[C:10]/1=[C:11](\[NH:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][N:19]=1)/[CH2:12][CH2:13][CH2:14][CH3:15].Cl>CC(O)C>[CH2:12]([C:11]1[N:16]([CH2:17][C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][N:19]=2)[C:4](=[O:3])[CH:5]=[C:6]2[NH:7][N:8]([CH3:25])[C:9](=[O:24])[C:10]=12)[CH2:13][CH2:14][CH3:15]

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-88191b816899429ba231f0a331e20ca7
Source dataset
uspto-grants-2013_06
Patent number
US08455485B2

Reaction notes

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