Disubstituted Dichlorobenzophenones, Isomeric Dichlorobenzhydrols and Related Compounds

A New Bromination Method for Phenols and Anisoles: NBS/HBF4·Et2O in CH3CN

“…4-Bromo-3-chlorophenol : mp 67−68 °C (lit . mp 67.5−69 °C); 1 H NMR 5.50 (s, 1H), 6.63 (dd, J = 8.7, 2.8, 1H), 6.97 (d, J = 2.8, 1H), 7.43(d, J = 8.7, 1H); MS 210, 208, 206 (M + , 24, 100, 82).…”

Spirolactones of xanthene. IV New method of xanthone synthesis by oxidation of novel spirolactones of dibenzo[c,h]xanthene and xanthenes.

“…1). In the course of further investigation of this novel reaction, we found that the reaction proceeds when substituted phenols are used in place of 1-naphthol to give novel spirolactones (6,10,14 and 18) of xanthene as shown in Chart 1. The molecular structure of 14 was also determined by the Xray diffraction method (Fig.…”

Synthesis of phenyl-substituted 1-aminotetralines

“…The apparently exclusive formation of the cis isomer is somewhat surprising in this instance, since no particular steric hindrance to the approach of the reducing species from either side would be anticipated from molecular models. Sodium borohydride reduction of the methylimine (18) derived from 4-phenyl-l-tetralone11 (17) gave the expected 1:1 mixture of cisand trans-Nmethyl-4-phenyl-l-aminotetraline (19 and 20), which were easily separated by fractional crystallization.…”

“…Conceivably, the use of reducing conditions which result in the formation of radical anions, such as dissolving metal reductions, would lead to the presumably thermodynamically favored trans isomer 20, if the reaction intermediate has an appreciable half-life. However, treatment of 18 with sodium in ethanol resulted in only a 50% yield of the trans isomer 20. On the other hand, reduction of 18 with zinc in acetic acid produced mainly the desired trans isomer 20.…”