Sulfuric Acid → Methyl 2-fluoro-3-(methylamino)benzoate

HRID 534668Notes

Reaction equation

Cl.[NH2:2][C:3]1[C:4]([F:13])=[C:5]([CH:10]=[CH:11][CH:12]=1)[C:6]([O:8][CH3:9])=[O:7].S(=O)(=O)(O)O.[C:19](=O)(O)[O-].[Na+]>C=O>[F:13][C:4]1[C:3]([NH:2][CH3:19])=[CH:12][CH:11]=[CH:10][C:5]=1[C:6]([O:8][CH3:9])=[O:7]

Participants

Conditions

Temperature: 40 °C

Procedure

Methyl 3-amino-2-fluorobenzoate hydrochloride (18.65 g, 0.09 mol) was dissolved in a 37% formalin solution. While maintaining the temperature at 40° C. or lower, 98% sulfuric acid (680.81 g, 6.80 mol) was added dropwise thereto. Thereafter, the mixture was naturally cooled, and agitated for 2 hours at room temperature. The reaction mixture was poured into ice water, and was neutralized with sodium bicarbonate. The neutralized liquid was filtered, and washed with ethyl acetate. Then, the filtrate was extracted, and dried over anhydrous sodium sulfate. The sodium sulfate was filtered away, and then the concentration residue was purified by silica gel column chromatography (developer solvent: ethyl acetate/n-hexane=1/4), as a result of which 6.27 g (yield: 38%) of the indicated compound was obtained.

Workup

temperatureThereafter, the mixture was naturally cooled
filtrationThe neutralized liquid was filtered
washwashed with ethyl acetate
extractionThen, the filtrate was extracted
dry with materialdried over anhydrous sodium sulfate
filtrationThe sodium sulfate was filtered away
customthe concentration residue was purified by silica gel column chromatography (developer solvent: ethyl acetate/n-hexane=1/4)

Sources & evidence

ORD record: ord-1470868b0ce0465f886521e7bd02a91a
Source dataset: uspto-grants-2014_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08853440B2

Reaction notes

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