Methyl chloroformate → 4-Methoxycarbonyloxy-3-fluorobenzoic acid

HRID 21353Notes

Reaction equation

[F:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[OH:11])[C:5]([OH:7])=[O:6].Cl[C:13]([O:15][CH3:16])=[O:14].[OH-].[Na+]>O>[CH3:16][O:15][C:13]([O:11][C:10]1[CH:9]=[CH:8][C:4]([C:5]([OH:7])=[O:6])=[CH:3][C:2]=1[F:1])=[O:14]

Participants

Conditions

Temperature: -20 °C

Procedure

4-methoxycarbonyloxy-3-fluorobenzoic acid (VI) was synthesized from 3-fluoro-4-hydroxybenzoic acid (V) by reaction of the latter with methyl chloroformate. NaOH (90 mmol) and 3-fluoro-4-hydroxybenzoic acid (30 mmol) were dissolved in water (80 ml) and cooled to -20° C. Methyl chloroformate (45 mmol) was added dropwise to the mixture. The mixture was then stirred with a magnetic stir bar at 5° C. for four hours and left overnight in the refrigerator. The mixture was then acidified to pH 5 to precipitate 4-methoxycarbonyloxy-3-fluorobenzoic acid. The precipitates were filtered and crystallized from acetonitrile to afford the clean product, 4-methoxycarbonyloxy-3-fluorobenzoic acid (VI), in a 77% yield.

Workup

waitleft overnight in the refrigerator
customto precipitate 4-methoxycarbonyloxy-3-fluorobenzoic acid
filtrationThe precipitates were filtered
customcrystallized from acetonitrile

Sources & evidence

ORD record: ord-6e7542b50106400f83a25fb640e5a93d
Source dataset: uspto-grants-1995_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05422037

Reaction notes

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