Benzene → Dicyclohexylcarbodiimide

Participants

Reaction Steps

They are heated to reflux into 200 ml benzene, 33 g of the thiourea obtained in the step G, together with 16 g dicyclohexyl carbodiimide for 5 hours. After achievement of the reaction, it is cooled, washed with water than with an aqueous solution of sodium carbonate and further with water. It is dried and concentrated to dryness under vacuum, the residue is taken up with 100 ml methanol and 20 ml water, then the pH value is adjusted to 1 with concentrated hydrochloric acid. The end of the reaction is followed by TLC on silica plates with chloroform 7--ethanol 3 (revelation UV and Iodoplatinate). It is neutralized after dilution with water using sodium carbonate then sodium hydroxide to obtain a pH value of 12. It is extracted with methylene chloride, the organic solution is washed with water, dried, filtered and concentrated to dryness. 37 g of raw product are produced which are washed with isopropyl ether and 24 g of the pure compound are obtained. The product is recrystallized from ethyl acetate containing a little methanol. MP=164.8°165.2° C.

Provenance & Evidence