Hydrochloric Acid → 6-methyl-5-nitroisoquinolin-1(2H)-one

Temperature

22 °C

1-chloro-6-methyl-5-nitroisoquinoline (50 g, 225 mmol) was suspended in THF (500 mL, 10 mL/g) and treated with 5 N aq HCl (500 mL, 10 mL/g). The suspension was stirred vigorously in a 2 L Morton Flask under a reflux condenser and heated with a heating mantle to reflux overnight (14 h). The resulting suspension was allowed to cool to room temperature (22° C.). The solid was removed by suction filtration and the filtrate set aside. The solid was washed with water (100 mL), Et2O (2×100 mL) and hexane (100 mL), then air-dried to afford 40 g as a light yellow powder. The reserved filtrate was concentrated in vacuo to a volume of ˜500 mL to afford a second crop of product. The second crop was washed with water (100 mL), Et2O (2×100 mL) and hexane (100 mL), then air-dried to afford 4 g as an orange powder. A total of 44 g (87% yield) of the title compound were isolated in this fashion. MS (M+H)+ 205.

1. temperatureheated with a heating mantle
2. temperatureto reflux overnight (14 h)
3. customThe solid was removed by suction filtration
4. washThe solid was washed with water (100 mL), Et2O (2×100 mL) and hexane (100 mL)
5. customair-dried
6. customto afford 40 g as a light yellow powder
7. concentrationThe reserved filtrate was concentrated in vacuo to a volume of ˜500 mL
8. customto afford a second crop of product
9. washThe second crop was washed with water (100 mL), Et2O (2×100 mL) and hexane (100 mL)
10. customair-dried
11. customto afford 4 g as an orange powder

ORD record

ord-5198d6628f434eaaaa847ad573f2375b

Source dataset

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08440674B2