Hydrochloric Acid → N,N'-Dimethyl-N-[4-(piperidin-1-yl)but-2-yn-1-yl]urea

Participants

Reaction Steps

A solution of N,N'-dimethyl-N-(2-propynyl)urea (2.5 g, 0.02 mol) (Example A), paraformaldehyde (0.6 g, 0.02 mol), piperidine (1.7 g, 0.02 mol), and a spatula tip of cuprous chloride in 150 ml of anhydrous dioxane is allowed to reflux for two hours. After cooling the solution is made strongly acidic with a 2N solution of hydrochloric acid and washed with diethyl ether. The aqueous solution is then made basic by the addition of solid potassium carbonate until saturated, followed by extraction with diethyl ether (2X). The diethyl ether solution is dried over magnesium sulfate, filtered, and concentrated to afford a yellow oil. Nuclear Magnetic Resonance (NMR) (CDCl3): 4.81 (brs, 1H); 4.11 (t, J=1.9 Hz, 2H); 3.24 (t, J=1.9 Hz, 2H); 2.93 (s, 3H); 2.81 (d, J=4.4 Hz, 3H); 2.48 (m, 4H); 1.63 (m, 6H).

Provenance & Evidence