Diethyl Ether → 4-(Ethynyloxy)-1,1'-biphenyl

Participants

Reaction Conditions

Reaction Steps

To a two-necked, round-bottomed flask (100 mL) equipped with a nitrogen inlet adapter and rubber septum was added the vinyl ether 2 (2.0 g, 7.6 mmol, 1 eq), anhydrous diethyl ether (30 mL), and TMEDA (23 mmol, 3.3 mL, 3 eq), and then cooled at −78° C. 2.5 M n-Butyllithium (9.0 mL, 23 mmol, 3 eq) was then added drop-wise to the reaction mixture for over 5 min. The reaction mixture was then maintained at −78 C for 1 h and at −40° C. for 40 min, and then cooled to −78° C. while 10% ethanol in pentane (10 mL) was added drop-wise. After 10 min, the reaction mixture was then diluted with n-pentane (20 mL) and the washed with saturated solution of ammonium chloride (25 mL). The organic phase was later washed twice with water (20 mL) and then finally with brine (20 mL), dried over anhydrous sodium sulfate, filtered and concentrated to give brown oil. The oil was purified by column chromatography with hexane as the eluent to yield 3 as dark brown oil (0.84 g, 70%) that later crystallized out as brown amorphous solid: mp 48-49° C. The compound was placed in a round bottom flask and was flushed with nitrogen and kept at −78° C. to avoid the decomposition if it was not to be used immediately. 1H NMR (300 MHz, CDCl3): 7.64-7.52 (m, 4H, HAr), 7.48-7.41 (m, 2H, HAr), 7.40-7.34 (m, 3H, HAr), 2.13 (s, 1H, ≡—H) ppm; 13C NMR (75 MHz, CDCl3): 155.0, 140.1, 138.0, 128.9, 128.4, 127.4, 127.0, 115.4, 84.5, 33.5 ppm; IR (cm−1): 3317 (≡C—H), 3029, 2927, 2174 (C≡C), 1606, 1512, 1484, 1208, 1166, 1062, 1008, 941, 838, 641, 548, 450; HRMS (ESI) Calculated for C14H10 [M−H]− 193.0654. Found 193.0651; Elemental analysis Calculated. for C14H10O.0.13H2O: C, 85.54; H, 5.26. found: C, 85.54; H, 5.38.

Provenance & Evidence