THE PREPARATION OF SOME DERIVATIVES OF RETENOXAZOLE AND RETENIMIDAZOLE AND A STUDY OF THE REACTION MECHANISM¹

Abstract

retenequinone and anisaldehyde dissolved in 100 cc. of boiling absolute ethyl alcohol. The same procedure was Used as for the vanillin condensation. The product was recrystallized from dioxane, yield, 55%.#-(S',4'-Dimethoxyphenyl)retenoxazole (XVI). This compound was prepared from retenequinone and veratraldehyde dissolved in 100 cc. of boiling absolute ethyl alcohol. The same procedure was followed as for the vanillin condensation. It was recrystallized from dioxane, yield, 60%.g-(8',4'-Methylenedioxyphenyl)retenoxazole (XVII). This compound was prepared from retenequinone and piperonal dissolved in 100 cc. of boiling absolute ethyl alcohol. The same procedure was used as for the vanillin condensation. The product was crystallized from dioxane, yield, 62%.2-(a-Furfuryl)retenoxazole (XVIII). This compound was prepared from retenequinone and furfuraldehyde dissolved in 100 cc. of boiling absolute ethyl alcohol.At the end of thirty minutes, the reaction^mixture had set into a solid mass. After recrystallization from dioxane and then from alcohol, the compound was obtained as small, white needles, yield, 40%. Philadelphia, Pa. SUMMARY 1. The reaction of retenequinone and ammonia has been studied.2. A critical study has been made of the mechanisms previously assigned to the reaction of o-quinones and aromatic aldehydes in the presence of ammonia to form oxazoles and imidazoles.3. A.new mechanism, in agreement with• experimental findings, has been developed to explain the formation of 2-aryl retenoxazoles from retenequinone, aromatic aldehydes, and ammonia.4. A series of 2-aryl retenoxazoles and 2-aryl retenimidazoles has been prepared.

Design of Efficient Photoinduced Charge Separation in Donor–Copper(I)–Acceptor Triad

“…After purification, the aldehyde was deprotected by trifluoroacetic acid (TFA) in chloroform in quantitative yield. The construction of the imidazole heterocycle was then performed according to a modification of the Steck and Day protocol, , using milder conditions and extra dried reagents to favor the formation of the imidazole instead of the oxazole derivative. , Since the imidazole derivative 6 is very polar, and tends to stick on silica gel, the crude reaction mixture was engaged in the alkylation step without further purification. Toward this goal, the imidazole unit was deprotonated with cesium carbonate and alkylated with hexyl iodide to afford ligand L1 in 29% yield (two steps).…”

Reactions of Phenanthraquinone and Retenequinone With Amines Under Pressure

“…The assumption that imidazoles may be formed through the ammonolysis of oxazoles was tested by Kreps and Day (13). They subjected 2-phenylretenoxazole and concentrated aqueous ammonia to a temperature of 170-180°a nd a pressure of five hundred pounds for forty-nine hours, but observed no conversion to the corresponding imidazole.…”

“…Retenequinone. Retenequinone was prepared by the method of Kreps and Day (13). It was recrystallized from chloroform, yield 50%, m.p.…”