Reactive methylene groups. II. Stilbene formation in solvents

Abstract

As a means of comparing the reactivities of methylene groups in organic compounds& substances have been condensed, under comparable conditions, with aromatic aldehydes in solution in organic solvents. Benzene is the most satisfactory solvent.

THE PHOTOCHEMICAL BEHAVIOR OF SOME o-NITROSTILBENES

“…%,4-Dinitro-lf'-hydroxystilbene (Id). This was prepared according to the procedures of Hargreaves and McGookin (18) from 2,4-dimtrotoluene, 4-hydroxybenzaldehyde, and piperidine. They reported obtaining one isomer, trans-, m.p.…”

“…Absorption Spectra of the Mono-, Di-, and Tri-nitro-4'-dimethylamino- preparation of the stilbenes has been shown ( 17) to give irans-stilbenes. Hargreaves and McGookin (18), however, have reported obtaining one or the other isomer of 2,4-dinitro-4'-hydroxystilbene, depending on whether a solvent was employed in the reaction. Their work could not be duplicated as only one isomer, the trans, was obtained in both preparations.…”

“…of benzene was irradiated 14 hours, concentrated, and then chromatographed, the isatogen fraction contained 15 mg. of isatogen (39%) according to spectroscopic determination. methoxystilbene (18) in 500 ml. of thiophene-free benzene in a Pyrex flask was irradiated for 45 hours by direct sunlight.…”