N-bromobutanimide → methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylate

HRID 1961211Notes

Reaction equation

HRID 1961211 reaction equation
C1C(=O)N([Br:8])C(=O)C1.[CH3:9][C:10]1[S:14][C:13]([C:15]([O:17][CH3:18])=[O:16])=[CH:12][C:11]=1[C:19]1[N:23]([CH3:24])[N:22]=[CH:21][CH:20]=1>O1CCCC1>[Br:8][C:20]1[CH:21]=[N:22][N:23]([CH3:24])[C:19]=1[C:11]1[CH:12]=[C:13]([C:15]([O:17][CH3:18])=[O:16])[S:14][C:10]=1[CH3:9]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 57826485methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Product 1

HCID 57826393methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylateYield 92%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
70 °C

Procedure

NBS (2.03 g, 11.41 mmol) was added in portions to a 75 mL sealed tube reactor containing methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (2.1 g, 8.89 mmol) [prepared according to the procedure of Preparation 10] in Tetrahydrofuran (THF) (40 ml) at room temperature. The mixture was heated to 70° C. for 1 hour. The reaction mixture was partitioned between CHCl3 and H2O, the organic layer dried with Na2SO4, the reaction mixture adsorbed onto silica and purified via column chromatography (15-40% EtOAc/Hex) affording the title compound (2.57 g, 8.15 mmol, 92%): LC-MS (ES) m/z=316 (M+H)+.

Workup

  1. customsealed tube reactor
  2. customprepared
  3. customThe reaction mixture was partitioned between CHCl3 and H2O
  4. dry with materialthe organic layer dried with Na2SO4
  5. custompurified via column chromatography (15-40% EtOAc/Hex)

Sources & evidence

ORD record
ord-332f016a77d346359e9991bdecec1c31
Source dataset
uspto-grants-2013_04
Patent number
US08410158B2

Reaction notes

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