Which compound is more reactive towards acetylation, 4-aminophenol or 4-aminocyclohexanol? Does the delocalisation of the lone pair of electrons in the NH2 group mean that they are less available to attack the carbon making the 4-aminocyclohexanol more reactive? Or does the polarisation of the neighbouring molecule due to the higher electron density of the benzene ring make the 4-aminophenol more reactive?
4-aminocyclohexanol should be more reactive towards acetylation because the reactivity depends on the availability of the lone pair on N to be able to attack the C atom during acetylation. Since in 4-aminophenol the lone pair resonates in the benzene ring, its availability to attack will get reduced making it lesser reactive towards acetylation.