Potassium Carbonate → 5-(1-methyl-1H-pyrazol-5-yl)thiophene-2-carboxylic acid

HRID 1961000Notes

Reaction equation

Br[C:2]1[S:6][C:5]([C:7]([OH:9])=[O:8])=[CH:4][CH:3]=1.C([O-])([O-])=O.[K+].[K+].CC1(C)COB([C:23]2[N:27]([CH3:28])[N:26]=[CH:25][CH:24]=2)OC1>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>[CH3:28][N:27]1[C:23]([C:2]2[S:6][C:5]([C:7]([OH:9])=[O:8])=[CH:4][CH:3]=2)=[CH:24][CH:25]=[N:26]1

Participants

Conditions

Temperature: 80 °C

Procedure

To a solution of 5-bromo-2-thiophenecarboxylic acid (100 mg, 0.48 mmol) in dioxane/H2O (5:1, 6 mL) was added K2CO3 (267 mg, 1.93 mmol), tetrakistriphenylphosphine Pd(0) (28 mg, 24 umol) and 5-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)-1-methyl-1H-pyrazole (94 mg, 0.48 mmol). The reaction mixture was heated to 80° C. in a sealed tube for 12 h and was then partitioned between 6N NaOH and DCM. The pH of the aqueous phase was adjusted to ˜3 with 3M HCl and washed several times with DCM. The combined organic fractions were dried (Na2SO4), concentrated under vacuum and used directly without further purification (˜100 mg, quant.): LC-MS (ES) m/z=209 (M+H)+.

Workup

customwas then partitioned between 6N NaOH and DCM
washwashed several times with DCM
dry with materialThe combined organic fractions were dried (Na2SO4)
concentrationconcentrated under vacuum
customused directly without further purification (˜100 mg, quant.)

Sources & evidence

ORD record: ord-b3915dc7336c4200b2ebf6a35faf6d25
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08410158B2

Reaction notes

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