Water → 2-Ethyl-pyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl ester

HRID 1478689Notes

Reaction equation

HRID 1478689 reaction equation
[I-].[NH2:2][N+:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.[C:9]([O:15][CH2:16][CH3:17])(=[O:14])[C:10]#[C:11][CH2:12][CH3:13].C(=O)([O-])[O-].[K+].[K+].O>CN(C)C=O>[CH2:12]([C:11]1[C:10]([C:9]([O:15][CH2:16][CH3:17])=[O:14])=[C:4]2[CH:5]=[CH:6][CH:7]=[CH:8][N:3]2[N:2]=1)[CH3:13]

Participants

6

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 99169Ethyl pent-2-yn-1-oateHCID 2733704Pyridinium, 1-amino-, iodide (1:1)

Product 1

HCID 137381512-Ethyl-pyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl esterYield 57.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A solution of 1-aminopyridinium iodide (10 g, 40 mmol) [Aldrich 441503], ethyl 2-pentynoate (5.7 g, 45 mmol) [Aldrich 632112] and potassium carbonate (12.0 g, 90 mmol) were stirred in N,N-dimethylformamide (200 mL) at 20° C. for 16 h. The mixture was poured into water to give a tan suspension. The solid was filtered and washed with water to give the desired compound (5.0 g, 57%). LCMS for C12H15N2O2 (M+H)+: m/z=219.1. 1H NMR (300 MHz, DMSO-d6): δ 8.77 (m, 1 H), 8.00 (m, 1 H), 7.52 (m, 1 H), 7.05 (m, 1 H), 4.28 (m, 2 H), 3.00 (m, 2 H), 1.33 (m, 3 H), 1.24 (m, 3 H).

Workup

  1. customto give a tan suspension
  2. filtrationThe solid was filtered
  3. washwashed with water

Sources & evidence

ORD record
ord-f643118ef60f4bbfb62c9448dacb33a0
Source dataset
uspto-grants-2016_08
Patent number
US09403847B2

Reaction notes

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