In the title compound, C(23)H(19)NO(3), there is an intra-molecular O-H⋯N hydrogen bond, which forms a six-membered ring, and inter-molecular O-H⋯O hydrogen bonds stabilize the crystal structure.

In the title compound, C(25)H(18)O(2)S·C(4)H(8)O(2), there are inter-molecular O-H⋯O hydrogen bonds between the main mol-ecule and the solvent molecule. The thio-phene ring is oriented at dihedral angles of 70.87 (7) and 75.36 (4)° with respect to the mean planes of the two naphthyl ring systems.

The title Schiff base compound, C(18)H(14)N(2)O(3), has an inter-mediate state between NH and OH tautomers. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond. The dihedral angle between the naphthalene ring system and the benzene ring is 37.44 (5)°.

BACKGROUND Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. It is however not effective for overcoming the extremely high recalcitrance of softwood to biochemical conversion. Recent fundamental research in small-scale liquid hot wat...

a convenient and efficient procedure for the synthesis of 14-aryl or alkyl-14h-dibenzo[a,j]xanthenes by condensation of 2-naphthol and aldehydes in the presence of methylimidazolium hydrogensulfate, as a brönsted acidic ionic liquid ([hmim]hso4), is described. both aromatic and aliphatic aldehydes reactedeasily to afford the corresponding 14-aryl or alkyl-14h-dibenzo[a,j]xanthenes in good yield...