Water → HCID 20191005, compound

HRID 2119125Notes

Reaction equation

HRID 2119125 reaction equation
[N+:1]([C:4]1[CH:8]=[CH:7][NH:6][N:5]=1)([O-:3])=[O:2].[H-].[Na+].Br[CH2:12][CH2:13][C:14]([O:16][CH2:17][CH3:18])=[O:15].O>CN(C=O)C>[N+:1]([C:4]1[CH:8]=[CH:7][N:6]([CH2:12][CH2:13][C:14]([O:16][CH2:17][CH3:18])=[O:15])[N:5]=1)([O-:3])=[O:2]

Participants

6

Reactant 4

HCID 962WaterHCID 24758Sodium hydrideHCID 68320Ethyl 3-bromopropionateHCID 178526745HCID 178526745, compound

Product 1

HCID 20191005HCID 20191005, compoundYield 45.1%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A solution of 3-nitropyrazole (22.6 g.) in dry DMF (25 ml.) was added dropwise over 30 minutes to a suspension of sodium hydride (5.28 g.) in dry DMF (50 ml.) at 0°. The mixture was stirred for 30 minutes, ethyl 3-bromopropionate (36.8 g.) was added over 10 minutes, the mixture was kept at -15° for 17 hours and then allowed to warm to 20°. Water (550 ml.) was added, the solution was extracted with EtOAc (4×100 ml.) and the combined extracts were dried (MgSO4) and evaporated in vacuo to an oil. Fractionation on a silica medium pressure liquid chromatography column eluted with EtOAc/petrol (b.p.60°-80°) 1:1 v/v gave ethyl 3-(3-nitropyrazol-1-yl)propionate (19.2 g.) as a low melting solid. The n.m.r. spectrum in CDCl3 included the following resonances: 7 6 (d, 1H); 6.85 (d, 1H); 4.5 (t, 2H); 4.1 (q, 2H); 2.95 (t, 2H); 1.2 (t, 3H).

Workup

  1. waitthe mixture was kept at -15° for 17 hours
  2. temperatureto warm to 20°
  3. extractionthe solution was extracted with EtOAc (4×100 ml.)
  4. dry with materialthe combined extracts were dried (MgSO4)
  5. customevaporated in vacuo to an oil
  6. washFractionation on a silica medium pressure liquid chromatography column eluted with EtOAc/petrol (b.p.60°-80°) 1:1 v/v

Sources & evidence

ORD record
ord-cf2e0ceaadc4427e9687e65878ca200f
Source dataset
uspto-grants-1987_07
Patent number
US04683228

Reaction notes

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