Trifluoromethanesulfonic acid → t-butyl 3-bromo-4-methylbenzoate

HRID 2186056Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[CH3:11])[C:5]([OH:7])=[O:6].FC(F)(F)S(O)(=O)=O.C(=O)(O)[O-].[Na+]>CCOCC>[Br:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[CH3:11])[C:5]([O:7][C:4]([CH3:8])([CH3:5])[CH3:3])=[O:6]

Participants

Conditions

Temperature: -30 °C

Procedure

A mixture of 3-bromo-4-methylbenzoic acid (10.75 g, 50 mmol) in dry ether (50 mL) in a glass bomb was cooled to −30° C. and isobutylene gas was bubbled in to give a total reaction volume of approximately 150 mL. Trifluoromethanesulfonic acid (0.22 g, 2.5 mmol) was added dropwise to the stirred mixture, and the bomb was sealed. The reaction was allowed to warm to RT and was stirred for 6 d. The bomb was opened carefully, and 5% sodium bicarbonate (50 mL) was added slowly. The mixture was allowed to stir for 15 min and ether (250 mL) was added. The layers were separated and the organic layer was washed with 5% sodium bicarbonate (2×50 mL) and then with brine (50 mL). Drying (magnesium sulfate) and concentration gave the title compound (12.88 g, 95%) as a yellow oil. TLC Rf 0.68 (toluene); 1H NMR (250 MHz, CDCl3) δ8.13 (d, J=1.7 Hz, 1 H), 7.81 (dd, J=7.9, 1.7 Hz, 1 H), 7.27 (d, J=7.9 Hz, 1 H), 2.44 (s, 3H), 1.59 (s,9 H); IR (CCl4) 1715, 1368, 1297, 1255, 1170, 1123, 1115 cm−1; MS(ES) m/e 273.0 [M+H]+, 271.0 [M+H]+, 214.8 [M+H−C4H8]+.

Workup

customisobutylene gas was bubbled in
customto give a total reaction volume of approximately 150 mL
customthe bomb was sealed
temperatureto warm to RT
stirringto stir for 15 min
customThe layers were separated
washthe organic layer was washed with 5% sodium bicarbonate (2×50 mL)
customDrying
concentration(magnesium sulfate) and concentration

Sources & evidence

ORD record: ord-63cf61023bde46eebd51cd7aa9d8e91a
Source dataset: uspto-grants-2002_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06403578B1

Reaction notes

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