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

HRID 60891Notes

Reaction equation

HRID 60891 reaction equation
I[C:2]1[CH:11]=[CH:10][C:9]([CH3:12])=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].[CH3:13][N:14]1[CH:18]=[C:17](B2OC(C)(C)C(C)(C)O2)[CH:16]=[N:15]1.C([O-])([O-])=O.[K+].[K+]>O1CCOCC1.O.CCOC(C)=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>[CH3:12][C:9]1[CH:10]=[CH:11][C:2]([C:17]2[CH:16]=[N:15][N:14]([CH3:13])[CH:18]=2)=[C:3]([CH:8]=1)[C:4]([O:6][CH3:7])=[O:5]

Participants

8

Reactant 3

HCID 11430Potassium CarbonateHCID 27739871-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazoleHCID 14263946Benzoic acid, 2-iodo-5-methyl-, methyl ester

Product 1

HCID 117727848Methyl 5-methyl-2-(1-methyl-1H-pyrazol-4-yl)benzoateYield 87.5%

Reagents, catalysts & solvents 4

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
100 °C

Procedure

A stirred solution of 2-iodo-5-methylbenzoic acid (17.3 g, 66.0 mmol) and concentrated H2SO4 (3 mL) in MeOH (200 mL) was heated at reflux for 18 h. After this time, the reaction mixture was cooled to rt, concentrated to one third volume, diluted with EtOAc (300 mL), washed with saturated NaHCO3 (2×200 mL), dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The resulting residue was dried under high vacuum to afford methyl 2-iodo-5-methylbenzoate as a colorless oil (18.2 g, quant.). 1H NMR (300 MHz, CDCl3) δ 7.84 (d, J=8.1 Hz, 1H), 7.62 (d, J=1.9 Hz, 1H), 6.99-6.96 (m, 1H), 3.92 (s, 3H), 2.33 (s, 3H). A stirred suspension of methyl 2-iodo-5-methylbenzoate (18.2 g, 66.0 mmol), 1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (15.2 g, 73.3 mmol), K2CO3 (27.5 g, 200 mmol), and Pd(PPh3)4 (11.5 g, 9.99 mmol) in 1,4-dioxane (150 mL) and H2O (50 mL) was heated at 100° C. for 18 h under nitrogen. After this time, the reaction mixture was cooled to rt, diluted with EtOAc (400 mL), washed with saturated NaHCO3 (2×300 mL), dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The resulting residue was purified by flash column chromatography on silica gel eluting with 0% to 80% EtOAc/hexanes to afford methyl 5-methyl-2-(1-methyl-1H-pyrazol-4-yl)benzoate as a colorless oil (13.3 g, 87%). 1H NMR (300 MHz, CDCl3) δ 7.55-7.25 (m, 5H), 3.94 (s, 3H), 3.80 (s, 3H), 2.38 (s, 3H).

Workup

  1. temperatureAfter this time, the reaction mixture was cooled to rt
  2. washwashed with saturated NaHCO3 (2×300 mL)
  3. dry with materialdried over anhydrous Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure
  6. customThe resulting residue was purified by flash column chromatography on silica gel eluting with 0% to 80% EtOAc/hexanes

Sources & evidence

ORD record
ord-8610ca8478f941f7a8e51d99b225668b
Source dataset
uspto-grants-2016_09
Patent number
US09440982B2

Reaction notes

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