Iodine → 7-(4-Oxo-pentyloxy)-1,3-dihydro-imidazo[4,5-b]quinolin-2-one

関与物質

反応手順

A solution of 5-[[5-[3-(2-methyl-1,3-dioxolan-2-yl)propoxy]-2-nitrophenyl]methylene]-2,4-imidazolidinedione (34.7 g, 92 mmol) in dimethylformamide (500 mL) was hydrogenated over 10% palladium on charcoal (3.5 g) at 200 p.s.i. in a low pressure hydrogenator. After 18 hours, the mixture was filtered through kieselguhr and concentrated in vacuo to afford a beige solid which was suspended in refluxing methanol (500 mL). Iodine (23.3 g, 92 mmol) was added portionwise and the mixture heated at reflux for a further 30 minutes before being cooled and diluted with 10% sodium thiosulfate solution (230 mL) and 10% sodium carbonate solution (75 mL). The mixture was concentrated to a volume of approximately 400 mL, the precipitate filtered off, washed with water and dried in vacuo of 70° C. to afford 1,3-dihydro-7-(4-oxopentoxy)-2H-imidazo[4,5-b]quinolin-2-one (22.1 g, 84%). An analytical sample was prepared by crystallizing a 10 g portion from aqueous dimethylformamide to give 7.8 g of pure material which had m.p. 294°-296° C. (dec.).

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