Caproic acid from ethyl n-butylmalonate

Into a 2-litre, three-necked flask, fitted with a separatory funnel, a mechanical stirrer and a reflux condenser, place a hot solution of 200 g. of potassium hydroxide in 200 ml. of water. Stir the solution and add slowly 200 g. of ethyl n-butylmalonate (Section 111,154). A vigorous reaction occurs and the solution refluxes. When all the ester has been added, boil the solution gently for 2-3 hours, i.e., until hydi-olysis is complete a test portion should dissolve completely in water. Dilute with 200 ml. of water and distil ofif 200 ml. of liquid in order to ensure the complete removal of the alcohol formed in the hydrolysis (1) it is best to connect the flask by means of a wide delivery tube to a condenser set for downward distillation (compare Fig. JI, 41,1 but with a mercury-sealed stirrer in the centre neck). Replace the separatory funnel and the reflux condenser. 

If desired, the distillation may be conducted under reduced pressure. The boiling points under various pressures are 99 /10 mm. and lll°/20 mm. a 3 fraction should be collected. 

Pelargonic acid (n Nonoic acid), CH3(CH2)7COOH. Equip a 1-litre, three-necked flask with a reflux condenser, a mercury-sealed stirrer, a dropping funnel and a thermometer. Place 23 g. of sodium, cut in small pieces, in the flask, and add 500 ml. of anhydrous n-butyl alcohol (1) in two or three portions follow the experimental details given in Sec-ti m 111,152 for the preparation of a solution of sodium ethoxide. When the sodium has reacted completely, allow the solution to cool to 70-80 and add 160 g. (152 ml.) of redistilled ethyl malonate rapidly and with stirring. Heat the solution to 80-90 , and place 182 5 g. (160 ml.) of n-heptyl bromide (compare experimental details in Section 111,37) in the dropping funnel. Add the bromide slowly at first until precipitation of sodium bromide commences, and subsequently at such a rate that the n butyl alcohol refluxes gently. Reflux the mixture until it is neutral to moist litmus (about 1 hour). 

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