Hydrochloric Acid → 5-(1-Hydroxyguanidin-3-yl)imino-4-methyl-7-(3-thienyl)-5,6,7,8-tetrahydroquinoline hydrochloride

Temperature

90 °C

A mixture of 4-methyl-7-(3-thienyl)-5,6,7,8-tetrahydroquinolin-5-one (243 mg), 1-amino-3-hydroxyguanidine p-toluenesulfonate (393 mg) and concentrated hydrochloric acid (0.2 ml) in ethanol (3 ml) was stirred at 90° C. (bath temperature) for 2 hours. The reaction solution was concentrated under reduced pressure, and to the residue were added ethyl acetate (30 ml), tetrahydrofuran (20 ml) and 0.2 N sodium hydroxide (20 ml). The mixture was shaken, and the separated upper layer was washed with 0.2 N sodium hydroxide (10 ml) and water (10 ml, thrice). To the upper layer was added 2 N hydrochloric acid (1 ml), and the mixture was concentrated under reduced pressure. To the residue was added ether (3 ml), and the mixture was stirred at 90° C. (bath temperature) for 2 hours and cooled to give crystals, which were filtered, washed with ethanol and dried to give 5-(1-hydroxyguanidin-3-yl)imino-4-methyl-7-(3-thienyl)-5,6,7,8-tetrahydroquinoline hydrochloride (Compound 103) (233 mg) as pale yellow crystals.

1. concentrationThe reaction solution was concentrated under reduced pressure
2. additionto the residue were added ethyl acetate (30 ml), tetrahydrofuran (20 ml) and 0.2 N sodium hydroxide (20 ml)
3. stirringThe mixture was shaken
4. washthe separated upper layer was washed with 0.2 N sodium hydroxide (10 ml) and water (10 ml, thrice)
5. additionTo the upper layer was added 2 N hydrochloric acid (1 ml)
6. concentrationthe mixture was concentrated under reduced pressure
7. additionTo the residue was added ether (3 ml)
8. stirringthe mixture was stirred at 90° C. (bath temperature) for 2 hours
9. temperaturecooled
10. customto give crystals, which
11. filtrationwere filtered
12. washwashed with ethanol
13. customdried

ORD record

ord-aaf718edf487410e86dcb5e172da3181

Source dataset

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06350749B1