Tetralin → 7-Benzyl-3-isopropyl-3,7-diazabicyclo[3.3.1]nonane

Participants

Reaction Steps

To a mixture of KOH pellets (85%, 11.62 g, 176 mmol) and the ketone (21) (6.0 g, 22 mmol) in triethylene glycol (100 mL) was added hydrazine (95%, 2.97 g, 88 mmol) in one portion in a 200-mL, jacketed flask equipped with a magnetic stirrer, a heating mantle, a standard condenser, a lower take-off condenser with a N2 inlet, and two glass stoppers. A heating temperature of 200°-210° C. for 4 h under N2 was produced by boiling tetralin (bp 207° C.) in the jacket. Cooling of the solution to RT was followed by the addition of chilled water (125 mL). Combined extracts (ether, 4×50 mL) of the suspension were washed with 10% NaOH (50 mL) and saturated NaCl (50 mL), dried (Na2SO4, 1 h), filtered, and concentrated (rotary evaporator then vacuum pump, overnight, RT/0.2 mm Hg) to a yellow oil (5.53 g, 97.3%). Analysis of the very slight crude amine (30) showed no carbonyl stretch in the IR spectrum, and thus it was used without further purification.

Provenance & Evidence