Acetonitrile → ethyl 4-bromo-3,5-dimethyl-1H-pyrrole-2-carboxylate

HRID 1372420Notes

Reaction equation

HRID 1372420 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8]([CH3:12])=[CH:9][C:10]=1[CH3:11])=[O:5])[CH3:2].C(=O)([O-])[O-].[K+].[K+].C(#N)C.[Br:22]N1C(=O)CCC1=O>O>[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8]([CH3:12])=[C:9]([Br:22])[C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

6

Reactant 4

HCID 6342AcetonitrileHCID 11430Potassium CarbonateHCID 67184N-bromobutanimideHCID 1374771H-Pyrrole-2-carboxylic acid, 3,5-dimethyl-, ethyl ester

Product 1

HCID 138486ethyl 4-bromo-3,5-dimethyl-1H-pyrrole-2-carboxylateYield 76%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
4 °C

Procedure

3,5-Dimethyl-1H-pyrrole-2-carboxylic acid ethyl ester (204 g), 177 g of potassium carbonate and 1428 mL of acetonitrile were stirred and cooled to 4° C. in an ice bath. N-Bromosuccinimide (228 g) was added in portions with vigorous stirring keeping the temperature under 17° C. The mixture was warmed to 20° C. and 2856 mL of water was slowly added. The precipitate was collected by vacuum filtration and washed three times with 400 mL of ethanol:water 1:2 each time. The solids were dried under vacuum at 60° C. to give 228 g (76% yield) of 4-bromo-3,5-dimethyl-1H-pyrrole-2-carboxylic acid ethyl ester as an off-white solid. 1H-NMR (dimethylsulfoxide-d6) δ 1.26 (t, 3H, CH3), 2.14, 2.17 (2×s, 2×3H, 2×CH3), 4.20 (d, 2H, CH2O), 11.75 (br s, 1H, NH). MS m/z 246, 248 [M+1].

Workup

  1. customunder 17° C
  2. temperatureThe mixture was warmed to 20° C.
  3. filtrationThe precipitate was collected by vacuum filtration
  4. washwashed three times with 400 mL of ethanol:water 1:2 each time
  5. customThe solids were dried under vacuum at 60° C.

Sources & evidence

ORD record
ord-c88544b884514b788614b421f729b09d
Source dataset
uspto-grants-2007_01
Patent number
US07157577B2

Reaction notes

Loading…