(CAS NO.: ), which is known as di-n-propyl ketone, could be produced through the following synthetic routes.

A mixture of 370 ml. (4 moles) of n-butyric acid and 123 g. (2.2 moles) of hydrogen-reduced iron powder is refluxed for 5 hours in a 1-l. flask equipped with a condenser. The apparatus is converted for downward distillation while an atmosphere of nitrogen is maintained. The nitrogen sweep is then stopped, the flask is strongly heated, and the entire distillate collected.

The crude product is washed with two 20-ml. portions of 10% sodium hydroxide solution and with one 20-ml. portion of water. The 4-heptanone is dried over 5 g. of anhydrous sodium sulfate, filtered, and distilled. The yield of 4-heptanone, b.p. 142–144°, n²⁵D 1.4031–1.4036, is 157–171 g. (69–75%).