1-ethynyl-2,4,5-trifluorobenzene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of trimethyl((2,4,5-trifluorophenyl)ethynyl)silane (10 g, 46 mmol, prepared using General Procedure J from 1-bromo-2,4,5-trifluorobenzene and ethynyltrimethylsilane), K2CO3 (0.64 g, 4.6 mmol) and MeOH (25 mL) was stirred at ambient temperature for about 3.5 h. The reaction was quenched with water and extracted with Et2O. The organic layer was concentrated under reduced pressure. The crude material was purified by silica gel chromatography using pentane as eluent to give the title compound as oil (1.5 g, 21% yield): LC/MS (Table 1, Method a) Rt=3.58 min; 1H NMR (CDCl3) 3.38 (s, 1 H), 7.00-7.06 (m, 1 H), 7.35-7.40 (m, 1 H). Additional product (5.6 g, ˜40% purity, ˜33%) was recovered from rotary evaporator condenser. The reaction was quenched with water extracted with Et2O The organic layer was concentrated under reduced pressure The crude material was purified by silica gel chromatography