Potassium Carbonate → Methyl 5-chloro-2-ethynylbenzoate

Participants

Reaction Steps

To a solution of methyl 5-chloro-2-[2-(trimethylsilyl)ethynyl]benzoate (10 g, 37.5 mmol) in MeOH (150 ml) was added K2CO3 (10.4 g, 75 mmol) at room temperature. The reaction mixture was stirred for 1 hour before being concentrated under reduced pressure. The residue was dissolved in deionized water (50 ml) and EtOAc (50 ml). The phases were separated and the aqueous layer was extracted with EtOAc (2×50 ml). The combined organic extracts were dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by FCC (50 g silica, Isolute cartridge, gradient of eluents; 95:5 Heptane:EtOAc to 9:1 Heptane:EtOAc) to give 5.75 g (55%) of the title compound as an orange oil that solidified upon standing. This material contained 30% of ethyl ester and was suitable for use without any further purification. LC-MS 38%, m/z=195.0/196.9, 1H NMR (500 MHz, Chloroform-d) δ ppm 7.93 (d, J=2.2 Hz, 1H), 7.55 (d, J=8.3 Hz, 1H), 7.45 (dd, J=8.3, 2.3 Hz, 1H), 3.94 (s, 3H), 3.43 (s, 1H).

Provenance & Evidence