The reaction of 2-propylphenol (I) first with NaNO2/AcOH, then with Na2S2O4 and finally with acetic anhydride gives the acetamide (II), which is treated with formaldehyde and tert-butylamine in ethanol yielding the tert-butylaminomethyl derivative (III). The hydrolysis of (III) with 6M HCl affords the aminophenol (IV), which is finally condensed with 4,7-dichloroquinoline (V) in refluxing ethanol.

The reaction of 2-isopropylphenol (I) first with NaNO2/AcOH, then with Na2S2O4 and finally with acetic anhydride gives the acetamide (II), which is treated with formaldehyde and tert-butylamine in ethanol yielding the tert-butylaminomethyl derivative (III). The hydrolysis of (III) with 6M HCl affords the aminophenol (IV), which is finally condensed with 4,7-dichloroquinoline (V) in refluxing ethanol.