Iodine → HCID 19866639, compound

Participants

Reaction Steps

A Grignard reagent was prepared from the product of step (d) above (12.3 g), magnesium (1.28 g) and iodine (1 crystal) in dry tetrahydrofuran (150 ml). 4-Methoxypyridine (5.76 g) was dissolved in dry tetrahydrofuran (300 ml) and stirred under nitrogen. The solution was cooled to -70°and treated with the above Grignard solution in one portion. After stirring for 10 minutes phenylchloroformate (6.6 ml) was added dropwise. After stirring at -70°for 30 minutes the mixture was allowed to warm up to room temperature. After stirring for 90 minutes the mixture was poured onto water and extracted with ether. The ether was washed with water and brine then dried and evaporated. The residue was taken up in toluene (250 ml) and stirred at room temperature. A solution of 3,4,5,6-tetrachloro-1,2-benzoquinone (13.0 g) in acetic acid (120 ml) was added dropwise. When addition was complete the mixture was stirred for a further 18 hours. The mixture was ice cooled and treated with a cold solution of sodium hydroxide (700 ml of 10%). After stirring for 10 minutes the mixture was filtered and separated. The aqueous filtrates were extracted with ether and the combined organic filtrates were extracted with dilute hydrochloric acid. The extracts were combined and basified with sodium hydroxide solution. The mixture was extracted with ether and the combined extracts washed with brine then dried and evaporated. Flash chromatography (1:1 ethyl acetate/petroleum ether) produced the subtitle compound as a clear oil 5.4 g. NMR (CDCl3) d 8.50 (d,1 H), 7.39 (d,1H), 7.60 (d,1H), 6.85 (d,1H), 6.77 (m,2H), 3.88 (s,3H), 3.86 (s,3H), 2.40 (s,3H).

Provenance & Evidence