Water → ethyl 4-chloro-5-methyl-1H-pyrazole-3-carboxylate

HRID 528787Notes

Reaction equation

HRID 528787 reaction equation
[CH3:1][C:2]1[NH:6][N:5]=[C:4]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[CH:3]=1.[Cl:12]N1C(=O)CCC1=O.O>CN(C=O)C>[Cl:12][C:3]1[C:4]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[N:5][NH:6][C:2]=1[CH3:1]

Participants

5

Reactant 3

HCID 962WaterHCID 31398ChlorosuccinimideHCID 77645Ethyl 5-methyl-1H-pyrazole-3-carboxylate

Product 1

HCID 604759ethyl 4-chloro-5-methyl-1H-pyrazole-3-carboxylateYield 95.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
60 °C

Procedure

To a solution of ethyl 5-methyl-1H-pyrazole-3-carboxylate (Maybridge, 4.41 g, 28.6 mmol) in DMF (14 mL) was added N-chlorosuccinimide (3.86 g, 28.9 mmol). The resulting solution was heated at 60° C. for 3 h and then cooled to room temperature. Water was added until a white precipitate formed, and the solid was collected by filtration washing with water. The solid was dissolved in CH2Cl2, washed with water (2×), dried over MgSO4 and concentrated in vacuo to provide the title compound (5.14 g, 90%) as a white solid. 1H NMR (CDCl3) δ 8.03 (s, 1H), 4.42 (q, J=7.0 Hz, 2H), 2.32 (s, 3H), 1.42 (t, J=7.1 Hz, 3H); MS(ESI+) m/z 188.9 (M+H)+.

Workup

  1. temperaturecooled to room temperature
  2. customformed
  3. filtrationthe solid was collected by filtration
  4. washwashing with water
  5. dissolutionThe solid was dissolved in CH2Cl2
  6. washwashed with water (2×)
  7. dry with materialdried over MgSO4
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-684ff452f35b4f79b29152e27c19e736
Source dataset
uspto-grants-2016_05
Patent number
US09346795B2

Reaction notes

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