Tetrahydrofuran → 2,2,5,5-Tetramethylcyclopentanamine

Participants

Reaction Steps

A flask was charged with 35 g. (0.61 mole) of 40% sodium dispersion in mineral oil. The oil was removed by washing with ethyl ether and decantation. The sodium was then mixed with 400 ml. of ether and a mixture of 32.8 g. (0.20 mole) 2,2,5,5-tetramethyladiponitrile, prepared by the method of Coffman et al., J. Am. Chem. Soc., 80, 2868 (1957), and 400 ml. of tetrahydrofuran was added slowly. The resulting mixture was stirred at room temperature for 4 hours, the excess sodium decomposed by dropwise addition of saturated aqueous ammonium chloride, the organic layer washed with water, dried (Na2SO4) and evaporated to afford 25.1 g. of crude 2,2,5,5-tetramethylcyclopentylimine. The imine was dissolved in 75 ml. of ethanol and added dropwise to a flask containing 23.3 g. (1 mole) sodium shot. An additional 75 ml. ethanol was added and the mixture heated at reflux until the remaining sodium metal was consumed. The reaction mixture was diluted with water, acidified to pH 1 with concentrated hydrochloric acid, the aqueous phase washed with ether then made strongly basic by addition of sodium hydroxide. The organic layer was extracted with ether, washed with brine, dried (Na2SO4) and evaporated to dryness. The residue was distilled in vacuo to afford 6.6 g. (23%) of the desired amine, B.P. 60-61° C. (20 mm.).

Provenance & Evidence