4,5-Benztropolone and Related Compounds¹

Abstract

Jan., 1950 4,5-BENZTROPOLONE AND RELATED COMPOUNDS 379 2. Picrasmin and isoquassin are identical. 4. Neoquassin (GHsoOa) is a hydroxy com-3. Quassin is a molecular complex containing pound and isoquassin (CztHtsOa) is the correisoquassin and neoquassin in approximately sponding ketone. equal amounts.

The Effect on Naturally Occurring Naphthoquinones on Velvetleaf (Abutilon theophrasti) Germination

“…Structures of the compounds tested and their antigermination activities against velvetleaf are given in Effective concentrations for many compounds are similar to those reported by Rietveld (12) (1 mM) for germination inhibition by juglone in a similar test involving 16 different seed species. Compounds giving 100% germination (as compared to controls) at levels of 10 mM were not tested at higher concentrations.…”

Cyclic Voltammetry of Two Analogue K-Group Vitamin Compounds in Dimethylsulfoxide

“…The electron number corresponding to reduction peak 6 was estimated with respect to the monoelectronic reduction wave of menadione (n ¼ 1.9) (Figure 2) and by controlled potential electrolysis (n ¼ 2.2). This result and the absence of the reversible peak 3-4, shown in Figure 4a, let us propose that the selfprotonation reactions (9,11) have been essentially suppressed. This is because phthiocol (pKa DMSO Х pKa phenol DMSO ¼ 18.03) is a weaker acid than benzoic acid (pKa DMSO ¼ 11) [20].…”

“…Phthiocol was synthesized following a procedure previously described [11]. Dimethylsulfoxide HPLC grade dried over 4 Å molecular sieves, was used as the solvent.…”

Tropones and Tropolones

“…Recent reinvestigation of these 4,5-benzotropone derivatives has been confined to dipole moment (29,442) and spectroscopic studies (399, 442). 424), and methoxymethyl ethyl ketone (116). The resulting ethers, but not the free tropolones, yield 2,4-dinitrophenylhydrazones and other carbonyl derivatives (240,423,424).…”

“…Although a methyl ether of the bromo derivative has been obtained with diazomethane (268), the formation of the ether of the parent compound by this method (268) has been disputed (66). The oily ether obtained (66) by the action of methyl p-toluenesulfonate yields a 2,4-dinitrophenylhydrazone (66), as do the ethers of 4,5-benzotropolone (240,423,424), in marked contrast to the ethers of tropolone and its monocyclic derivatives.…”