David J. Crouse

An Efficient Steric Controlled Photo-Fries Rearrangement in the Naphthalene Series

Abstract For the work on the synthesis of 2-acyl-5-methoxynaphthoquinones as tricyclic analogues of daunomycinone1, we wanted to develop an efficient regioselective synthesis of 5-methoxy-2-acyl-1-naphthols without using Lewis acids. This requirement precluded the use of the thermal Fries but not the photo-Fries rearrangement. Although the mechanistic aspects of the photo reaction have received much study2, the reaction has been little used preparatively3 because it usually gives poor yields of hydroxy ketones even when only one product is possible.

Preparation of a 4-monoketal of juglone methyl ether

Abstract Oxidation of 5-methoxy-1-naphthol with thallium trinitrate in ethylene glycol/trimethylorthoformate gives the 4-ethylene ketal of juglone methyl ether.

Kinetics of 4-acetoxybenzoic acid synthesis

High-temperature polymers have found a wide range of uses in recent decades. 4-Acetoxybenzoic acid (PABA) is used as a monomer for the polymerization of one such thermotropic polymer. Information on polycondensation of already prepared PABA is available in the literature. However, information in the literature concerning the kinetics of PABA synthesis by acetylation of 4-hydroxybenzoic acid (PHBA) using acetic anhydride is limited. The reaction between PHBA and acetic anhydride in a carrier solvent, Therminol-66 (T-66), was investigated. Aspects of the global reaction mechanism and the dependence of the reaction rate on acetic anhydride concentration were determined. Nuclear Magnetic Resonance (NMR) spectrometry and gravimetric analysis were used to analyze the samples collected from a 3 l batch reactor. The specific rate constant and the activation energy of the reaction were determined and a rate equation for the reaction suggested.