A solution of 147 g. (1.50 moles) of cyclohexanone, 157 g. (1.80 moles) of morpholine (Note 1), and 1.5 g. of p-toluenesulfonic acid in 300 ml. of toluene is heated to boiling in a 1-l. round-bottomed flask to which is attached a water separator2 under a reflux condenser. The separation of water begins at once and ceases after 4 or 5 hours. An indented Claisen stillhead is attached to the flask, and the reaction mixture is distilled. Most of the toluene is removed at atmospheric pressure. 1-Morpholino-1-cyclohexene is collected as a colorless liquid at 118–120°/10 mm.; nD25 1.5122–1.5129 (Note 2). It weighs 180–200 g. (72–80%).