Into 200 ml of N,N-dimethylformamide and 50 ml of water was added 16 g of 6-hydroxycarbostyril and 17 g of K2CO3, while the mixture was stirred at a room temperature, 31 g of N-cyclohexyl-N-(2-hydroxyethyl)-γ-bromocrotonamide was added dropwise. After the addition the reaction mixture was stirred for 3 hours and was concentrated. To the residue thus obtained 500 ml of chloroform was added and washed with water, a dilueted NaOH aqueous solution and water. The organic layer was concentrated. The residue thus obtained was recrystallized from methanol-water to obtain 27 g of 6-{3-[N-(2-hydroxyethyl)-N-cyclohexylaminocarbonyl]-2-propenyloxy}-carbostyril as in the form of colorless needle-like crystals. The chemical structure of this substance was identified by the NMR spectrum and the data of elementary analysis.
