Tris(1,1-dimethylethyl)phosphine → N-(3-(1,3-dioxolan-2-yl)phenyl)dibenzo[b,d]thiophen-4-amine

Participants

Reaction Steps

A clean and dry 1000 ml round bottom flask equipped with a reflux condenser, magnetic stir bar, and thermometer with adapter was prepared and purged with nitrogen. A solution of 4-bromodibenzo[b,d]thiophene (RS-1-170, 10.7 g, 0.0407 mol) in anhydrous toluene (500.0 ml) was then prepared and transferred to the reaction flask via cannula. 3-aminobenzaldehyde ethylene acetal (8.1 g, 0.0488 mol) was added by syringe. The reaction solution was purged with a strong nitrogen flow for 20 minutes. Sodium tert-butoxide (5.86 g, 0.0610 mol) and Pd2dba3 (1.10 g, 0.0012 mol) were then added manually, followed by the addition of tri-tert-butylphosphine (0.65 g, 0.0032 mol) in toluene (˜10 ml) via syringe. The vessel was heated to reflux for approximately 2 hours. The reaction was then cooled to room temperature and filtered through a Celite and silica gel pad. Solvent was removed by rotary evaporation. The crude material was dissolved in a 2:1 hexane/ethyl acetate solution purified by flash column chromatography using a gradient elution system of ethyl acetate/hexane. This provided pure product confirmed by NMR.

Provenance & Evidence