Hydroxylamine → HCID 118079803, compound

Temperature

100 °C

A screw-cap vial equipped with a magnetic stir bar was charged with a solution of (S)-(7-bromo-3-methyl-3,4-dihydroquinoxaline-1(2H)-yl)(2-fluorophenyl)methanethione (0.021 g, 0.057 mmol) in dimethylsulfoxide (0.5 mL) and hydroxylamine (50% in water, 0.035 mL, 0.575 mmol). The vial was capped, and the solution heated to 100° C. for 90 min. Heating was increased to 150° C. for 3 h, and then the solution was stirred at rt overnight. Additional hydroxylamine (50% in water, 0.035 mL, 0.575 mmol) was added and heating resumed at 150° C. for 5 h. Potassium carbonate (ca. 10-15 mg) was added and heating resumed at 100° C. for 5 h. The mixture was diluted with water (1 mL) and extracted with dichloromethane. The dichloromethane extract was washed with 5% aqueous sodium chloride solution (1 mL) and concentrated. The crude product was purified by preparative thin layer chromatography (1×1000 micron plate, eluting with 4:1 hexanes-ethyl acetate). The major band was isolated to afford (S)-3-(7-bromo-3-methyl-3,4-dihydroquinoxaline-1(2H)-yl)benzo[d]isoxazole (0.010 g, 51%). MS (ESI, pos. ion) m/z 344, 346 [M+1].

1. customA screw-cap vial equipped with a magnetic stir bar
2. customThe vial was capped
3. temperatureHeating
4. temperaturewas increased to 150° C. for 3 h
5. temperatureheating
6. waitresumed at 150° C. for 5 h
7. temperatureheating
8. waitresumed at 100° C. for 5 h
9. extractionextracted with dichloromethane
10. extractionThe dichloromethane extract
11. washwas washed with 5% aqueous sodium chloride solution (1 mL)
12. concentrationconcentrated
13. customThe crude product was purified by preparative thin layer chromatography (1×1000 micron plate, eluting with 4:1 hexanes-ethyl acetate)
14. customThe major band was isolated

ORD record

ord-3afe226fb45546278ef5098e5108aac8

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09422281B2