Methyl iodide → 2H-1,4-Benzoxazine, 3,4-dihydro-4-methyl-

Temperature

2.5 °C

Into a 250 mL 3-necked round bottom flask was placed a solution of 3,4-dihydro-2H-benzo[b][1,4]oxazine (4.8 g, 35.51 mmol) in tetrahydrofuran (50 mL). To the above was added NaH (2.3 g, 57.50 mmol) in several batches, while cooling to a temperature of 0-5° C. The mixture was stirred for 30 minutes at 0-5° C. To the above was added iodomethane (9.0 g, 63.41 mmol) dropwise with stirring, white cooling to a temperature of 0-5° C. The resulting solution was allowed to react, with stirring, overnight while the temperature was maintained at room temperature. The reaction progress was monitored by TLC (ethyl acetate/petroleum ether=1:2). A filtration was performed. The filtrate was concentrated by evaporation under vacuum using a rotary evaporator. The residue was purified by eluting through a column with a 1:100 ethyl acetate/petroleum ether solvent system. This resulted in 3.0 g (50%) of 4-methyl-3,4-dihydro-2H-benzo[b][1,4]oxazine as yellow oil.

1. customInto a 250 mL 3-necked round bottom flask was placed
2. stirringwith stirring
3. temperaturewhite cooling to a temperature of 0-5° C
4. customto react
5. stirringwith stirring, overnight while the temperature
6. temperaturewas maintained at room temperature
7. filtrationA filtration
8. concentrationThe filtrate was concentrated by evaporation under vacuum
9. customa rotary evaporator
10. customThe residue was purified
11. washby eluting through a column with a 1:100 ethyl acetate/petroleum ether solvent system
12. customThis resulted in 3.0 g (50%) of 4-methyl-3,4-dihydro-2H-benzo[b][1,4]oxazine as yellow oil

ORD record

ord-9776a83e6587418bac195ec59360136a

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07696229B2