Estabrook and coworkers have developed an enzymatic analysis for the oxidation of catechol depicted in Figure 1b. The rate of this oxidation (k2) is so high that the
rate of the O-dealkylation reactions of monocatechol ethers (k1) may perhaps be conveniently followed by monitoring catechol concentrations as it is produced. That is with k2 >> k1, a combined dealkylation and oxidation enzymatic system might be developed to provide kinetic data on step 1, ie. on k1 values.
With this in mind, a series of appropriate substrates ie. O-monoalkyl catechol ethers needed to be prepared. That part of the overall scheme is the focus of the present work and was achieved as outlined in Figure 2.
Synthetically the yields of n-alkyl mono- and diethers levelled off at about 70%. Conditions were developed (by changing base to halide ratios, etc.) so as to optimize selectively the yields of mono- or diether. The evidence accumulated suggests that the monoethers were the precursors of the dialkylated products.
With the isopropyl compound the overall yields were much poorer (~20%), this being due to the ease with which the parent halide undergoes elimination under the reaction conditions. A surprising anomaly was the fact that with n-octyl bromide as reagent diether formation occurred exclusively under the present range of conditions.
Physical data (1H-NMR and IR) verified the structures of the compounds prepared. In general the various structural parameters e.g. the position of […] for the OH group in 1H-NMR, were insensitive to the nature of the alkyl group. This was also true for the pKa values for the series of monoalkyl catechol ethers.
Library of Congress Subject Headings
F. L. Scott
T. C. Morrill
Dhumrongvaraporn, Sujitra, "Synthesis of mono- and dialkyl catechol ethers" (1983). Thesis. Rochester Institute of Technology. Accessed from
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