2-Aminopyridine-3-boronic acid, pinacol ester → Tert-butyl 4-(2-aminopyridin-3-yl)-2-fluorobenzoate

HRID 596075Notes

Reaction equation

CC1(C)C(C)(C)OB([C:9]2[C:10]([NH2:15])=[N:11][CH:12]=[CH:13][CH:14]=2)O1.Br[C:18]1[CH:30]=[CH:29][C:21]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])=[C:20]([F:31])[CH:19]=1>C(O)CCC.C(OCC)(=O)C.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>[NH2:15][C:10]1[C:9]([C:18]2[CH:30]=[CH:29][C:21]([C:22]([O:24][C:25]([CH3:28])([CH3:26])[CH3:27])=[O:23])=[C:20]([F:31])[CH:19]=2)=[CH:14][CH:13]=[CH:12][N:11]=1

Participants

Conditions

Temperature: 130 °C

Procedure

A degassed mixture of 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-amine (2.4 g, 10.91 mmol), tert-butyl 4-bromo-2-fluorobenzoate (3.30 g, 12.00 mmol), Pd(PPh3)4 (0.63 mg, 0.0.545 mmol), 2.0 M Na2CO3aqueous solution (10.91 mL) in n-butanol (26 mL) was microwave heated to 130° C. for 10 min. The reaction was diluted with ethyl acetate (30 mL), and then washed with water (10 mL) and brine (10 mL). The organics were dried over sodium sulfate, filtered, concentrated, and then purified by flash chromatography (10-60% ethyl acetate/heptane eluent) to provide tert-butyl 4-(2-aminopyridin-3-yl)-2-fluorobenzoate (1.35 g, 43% yield). LCMS (m/z): 289.4 (MH+), 0.67 min.

Workup

washwashed with water (10 mL) and brine (10 mL)
dry with materialThe organics were dried over sodium sulfate
filtrationfiltered
concentrationconcentrated
custompurified by flash chromatography (10-60% ethyl acetate/heptane eluent)

Sources & evidence

ORD record: ord-084d300d64bc4ba5a29dc564fc2db4d7
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09242996B2

Reaction notes

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