Potassium Carbonate → Methyl 4-(1-methyl-1H-pyrazol-5-yl)thiophene-2-carboxylate

HRID 2392275Notes

Reaction equation

HRID 2392275 reaction equation
Br[C:2]1[CH:3]=[C:4]([C:7]([O:9][CH3:10])=[O:8])[S:5][CH:6]=1.C([O-])([O-])=O.[K+].[K+].[CH3:17][N:18]1[C:22](B2OC(C)(C)C(C)(C)O2)=[CH:21][CH:20]=[N:19]1>O1CCOCC1.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:17][N:18]1[C:22]([C:2]2[CH:3]=[C:4]([C:7]([O:9][CH3:10])=[O:8])[S:5][CH:6]=2)=[CH:21][CH:20]=[N:19]1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 49129081-methyl-5-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazoleHCID 12752071Methyl 4-bromothiophene-2-carboxylate

Product 1

HCID 57826540Methyl 4-(1-methyl-1H-pyrazol-5-yl)thiophene-2-carboxylateYield 70.1%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 218864351,4-Dioxane--water (1/1)Solvent

Conditions

Temperature
75 °C

Procedure

To a solution of methyl 4-bromo-2-thiophenecarboxylate (1.0 g, 4.5 mmol) in dioxane/H2O (5:1, 12 mL) was added K2CO3 (1.86 mg, 13.5 mmol), tetrakistriphenylphosphine Pd(0) (300 mg, 0.25 mmol), and 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.23 g, 5.9 mmol). The reaction mixture was heated to 75° C. in a sealed tube for 2 h. The reaction mixture was concentrated and purified on silica gel (EtOAc/Hex 10-40%) to give the title compound (701 mg, 70%) as a white solid: LC-MS (ES) m/z 223 (M+H)+.

Workup

  1. concentrationThe reaction mixture was concentrated
  2. custompurified on silica gel (EtOAc/Hex 10-40%)

Sources & evidence

ORD record
ord-3f8b747b6c924dc69697608c8e518f53
Source dataset
uspto-grants-2012_09
Patent number
US08273782B2

Reaction notes

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