Reaktionen mit Nitrosodisulfonat, XIX. Chinone aus aromatischen Aminen, insbesondere Benzochinone aus Anilinderivaten

Abstract

Derivate des Anilins rnit mindestens zwei a n Kohlenstoff gebundenen Substituenten (Alkyl-oder Alkoxygruppen) und einer freienp-oder o-Stellung werden in z. TI.

Characterization of the COQ5 Gene from Saccharomyces cerevisiae EVIDENCE FOR A C-METHYLTRANSFERASE IN UBIQUINONE BIOSYNTHESIS

“…The expected hydroquinone was oxidized during basic work-up, and a bright yellow oil (3) was obtained (110 mg, 92% yield). 1 4 mmol) in 400 ml of water was added freshly prepared potassium nitrosodisulfonate (6 g, 22.4 mmol) (41,42). To this purple solution, 2-methoxy-5-methylaniline (4) (1.68 g, 12.2 mmol) in 50 ml of acetone was added.…”

Studies of chromenes. Part 9. Syntheses of chromenequinones

“…Sublimation at 80-100 "C (0.17 mmHg) afforded deep yellow crystals, m.p. 79-80 "C, v,,,(KBr) 1 672, 1 647 and 1 574 cm-'; h,,,(EtOH) 263 (E 16 (6 H, s), 5.64 (1 H, d, J 10.0 Hz, 3-H), 6.43 (1 H, d, J 10.0 Hz, (2-Methylbut-3-yn-2-yloxy)-l,4-benzoquinone (7).-A solution of the ether (4) (0.580 g, 3.37 mmol) in acetone (3 ml) was slowly added to a stirred ice-cold solution of Fremy's salt (2.71 g, 1.0 mmol) in a mixture of water (360 ml) and acetone (100 ml) buffered with 0 . 1 6 7 ~ aqueous potassium dihydrogen phosphate (60 ml).…”

“…61-63 "C (from ethanol), v,,,(KBr) 1 743 and 1 512 cm-'; GH(CDC13) 3.73 (3 H, s), 3.77 (3 H, s), 6.69 (1 H,d, J3.0Hz), 6.75 (1 H,dd,J8.9 and 3.0 Hz), and 6.91 (1 H, d, J 8.9 Hz); Gc(CDCl,) 55. 7 Aqueous potassium hydroxide (10%; 194 ml, 0.35 mol) was added dropwise in an atmosphere of nitrogen and at room temperature to a stirred solution of the formate (52 g, 0.285 mol) in methanol (410 ml) containing sodium dithionite (3.1 g ) as antioxidant. The mixture was stirred for 1 h and then neutralised with 2~ aqueous hydrochloric acid and the mixture extracted with ether (3 x 300 ml).…”

“…Hydrolysis of the Quinone Ether Monoacetal (12).-Hydrolysis of the uncyclised monoacetal (12) was carried out as above to give the quinone ether (7) and a small quantity of chromenequinone (3) (ca. 5%).…”

Sodium Hypochlorite/Dowex 1X8-200: an Effective Oxidant for the Oxidation of Aromatic Amines to Quinones

“…Oxidation of aromatic amines to quinones is an important reaction in organic chemistry and a variety of oxidizing reagents such as potassium dichromate, 12 potassium nitrosodisulfonate, 13 ferric chloride, 14 sodium nitrate, 15 silver oxide and lead dioxide, 16 lead tetraacetate 17 and hydrogen peroxide 18 have been developed. Most of the reported reagents require vigorous conditions, 12Y13Y15 some require tedious work up, 17 give low yields 15Y16 or long reaction times.…”