反应详情

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.).

1. filtrationthe mixture was filtered through kieselguhr
2. concentrationconcentrated in vacuo
3. customto afford a beige solid which
4. temperaturethe mixture heated
5. temperatureat reflux for a further 30 minutes
6. temperaturebefore being cooled
7. concentrationThe mixture was concentrated to a volume of approximately 400 mL
8. filtrationthe precipitate filtered off
9. washwashed with water
10. customdried in vacuo of 70° C.