Crystal structure prediction with the supramolecular synthon approach: Experimental structures of 2-amino-4-ethylphenol and 3-amino-2-naphthol and comparison with prediction

Two earlier crystal structure predictions (CSP) of aminophenol compounds are checked against experimental structure determinations. One of the predictions classified originally as “good” is verified and is now seen to be somewhat correct. The other prediction, which was classified earlier as “unclear”, is incorrect. The two experimental crystal structures are characterized by small and large synthons both of which contain O–H⋯N and N–H⋯O hydrogen bonds. The evolving nature of the CSP exercise is noted.