Potassium Carbonate → Dimethyl 1-(2-ethoxyethyl)-4-nitro-1H-pyrazole-3,5-dicarboxylate

HRID 2100456Notes

Reaction equation

HRID 2100456 reaction equation
[N+:1]([C:4]1[C:5]([C:13]([O:15][CH3:16])=[O:14])=[N:6][NH:7][C:8]=1[C:9]([O:11][CH3:12])=[O:10])([O-:3])=[O:2].[CH2:17]([O:19][CH2:20][CH2:21]Br)[CH3:18].C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O>[CH2:17]([O:19][CH2:20][CH2:21][N:7]1[C:8]([C:9]([O:11][CH3:12])=[O:10])=[C:4]([N+:1]([O-:3])=[O:2])[C:5]([C:13]([O:15][CH3:16])=[O:14])=[N:6]1)[CH3:18]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 611412-Bromoethyl ethyl etherHCID 1421248dimethyl 4-nitro-1H-pyrazole-3,5-dicarboxylate

Product 1

HCID 57446145Dimethyl 1-(2-ethoxyethyl)-4-nitro-1H-pyrazole-3,5-dicarboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

Dimethyl 4-nitro-1H-pyrazole-3,5-dicarboxylate (2.0 g, 8.83 mmol) was added to a solution of 2-ethoxyethyl bromide (1.18 mL, 10.45 mmol) and potassium carbonate (1.32 g, 9.56 mmol) in N,N-dimethylformamide (35 mL) and the reaction mixture stirred for 48 hours at room temperature. The reaction mixture was concentrated in vacuo and the residue partitioned between ethyl acetate (200 mL) and water (100 mL). The organic layer was separated, dried over magnesium sulphate and concentrated in vacuo. The crude product was purified by column chromatography on silica gel eluting with pentane: ethyl acetate 100:0 to 70:30 to yield the title product, 1.63 g. 1H NMR (CDCl3, 400 MHz) δ: 1.07 (s, 3H), 3.41 (q, 2H), 3.73 (t, 2H), 3.89 (s, 3H), 3.94 (s, 3H), 4.76 (t, 2H). MS APCI+ m/z 302, [MH]+

Workup

  1. concentrationThe reaction mixture was concentrated in vacuo
  2. customthe residue partitioned between ethyl acetate (200 mL) and water (100 mL)
  3. customThe organic layer was separated
  4. dry with materialdried over magnesium sulphate
  5. concentrationconcentrated in vacuo
  6. customThe crude product was purified by column chromatography on silica gel eluting with pentane: ethyl acetate 100:0 to 70:30

Sources & evidence

ORD record
ord-f49db22f41b84b43b2a68420a1540687
Source dataset
uspto-grants-2009_08
Patent number
US07572799B2

Reaction notes

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