4-Bromothioanisole → HCID 57227238, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 4-bromothioanisole (48.5 g) in THF (600 mL) was cooled to -70° C. and a 2.5M solution of n-butyllithium in hexane (96 mL) was slowly added over 20 min. The resulting suspension was stirred for 1 h allowing the temperature of the cooling bath to raise to -50° C. It was then cooled back to -70° C. and a solution of dioxolanone from Step 2 (29.8 g) in TBF (100 mL) was added dropwise over 30 min. The reaction was allowed to proceed for another 30 min. and then quenched with AcOH (23 mL) always at -70° C. The reaction mixture was allowed to warm to r.t., diluted with a 25% aqueous solution of NH4OAc and extracted with EtOAc (2 L). The organic layer was dried over MgSO4 and concentrated. The resulting crude product was purified by flash chromatography (2→3→5→7% EtOAc in hexane) to give a light yellow solid. 1H NMR(CD3COCD3): mixture of diastereomers δ0.50 (0.5H, m), 0.68 (1.5H, s), 0.72 (1.5H, t), 0.97 (1.5H, t), 0.98 (9H, s), 1.38 (1.5H, s), 1.52 m), 1.68 (0.5H, m), 2.10 (0.5H, m), 2.48 (3H, 2s), 4.85 (1H, s, OH), 5.01 (0.5H, s), 5.32 (0.5H, s), 7.22-7.30 (2H, m), 7.50 (2H, dd).

Provenance & Evidence