Nitrogen → 2-(Thiophen-2-yl)aniline

Participants

Reaction Steps

AB427 (The following reaction is carried out in an N2 atmosphere.) Dissolve Tetrakis-(triphenylphosphine)-palladium(0) (297 mg, 0.26 mmol) and 2-Bromo-thiophene (837 mg, 5.13 mmol) in DME (42 mL), degas the reaction mixture carefully (5 times) and flush with N2. After 10 min stirring add 2-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenylamine (1.24 g, 5.64 mmol) and a 1M aqueous NaHCO3 solution (15.4 mL, 15.4 mmol), degas the reaction mixture again carefully (5 times) and flush with N2. Stir the mixture for 3 h at 95° C. Cool mixture to rt, remove solvent under reduced pressure and partition the residue between EtOAc and water. Extract the separated aqueous layer with EtOAc (3 times). Wash combined organic layer with brine and dry it with Na2SO4. Purify the crude product by flash chromatography (silica gel 60, CyH/EtOAc 15+1] to obtain 2-Thiophene-2-yl-phenylamine (55) as a brown solid (825 mg, 92%). 1H NMR (400 MHz, CDCl3): 4.40-6.00 (m, 2H); 6.88 (td, 1H, J1=7.6 Hz, J2=1.0 Hz); 6.93 (dd, 1H, J1=8.0 Hz, J2=1.0 Hz); 7.07 (dd, 1H, J1=5.3 Hz, J2=3.5 Hz); 7.17 (td, 1H, J1=8.0 Hz, J2=1.5 Hz) 7.22 (dd, 1H, J1=3.5 Hz, J2=1.3 Hz); 7.30 (dd, 1H, J1=7.6 Hz, J2=1.5 Hz); 7.33 (dd, 1H, J1=5.3 Hz, J2=1.3 Hz).

Provenance & Evidence