Hexane → 2-Amino-5-(diethylamino)toluene

Participants

Reaction Steps

In a 500-mL Parr® hydrogenation vessel, Compound CD-1 (8.74 g, 38 mmol) was dissolved in hexane (20 mL) and aqueous pH 7.4 buffer (20 mL; Fisher Scientific: SB110-1; potassium phosphate monobasic-sodium hydroxide buffer, 0.05 M). RhCl3.xH20 (1.0 g, 3.8 mmol; Alfa Aesar) and tetrabutylammonium sulfate solution (4.4 mL, 50 wt % in H2O; 4.4 g, 3.8 mmol) were added sequentially. The biphasic mixture was shaken under hydrogen atmosphere (53 psi) for 14 days at rt. The reaction mixture was filtered through a Celite® pad. The aq. layer was separated and extracted with EtOAc (3×15 mL). The combined organic layers was washed with brine (˜25 mL), dried over anhydrous MgSO4, filtered, and concentrated by rotary evaporation under reduced pressure. The crude product was purified by flash silica gel chromatography (Isco Combiflash Rf®; 80 g RediSep silica gel cartridge, 0-100% EtOAc/hexanes over 20 column volumes @ 80 mL/min). Eluent from column volumes 1-6, containing unreacted Compound CD-1, were discarded, while column volumes 7-20 were combined and concentrated to give desired product, Compound CD-2, as an off-white solid (6.67 g, 74% yield).

Provenance & Evidence