Methanol → Benzenamine, 4-bromo-N-methyl-

To a stirred 2M solution of borane methyl sulfide complex in THF (580 mL, 1.16 mol) at 0° C. was slowly added a solution of N-(4-bromo-phenyl)-formamide (Example 1, Step (1), 93 g., 0.465 mol) in 280 mL of THF so that the temperature of the solution did not rise above 5° C. Once the addition of the formanilide was complete, the reaction was brought to reflux and stirred for 3 hours. The reaction was then cooled to 0° C. and 190 mL of methanol was added slowly to control the frothing of the reaction. Then hydrogen chloride gas was bubbled into the solution until the pH was approximately 2. The solvents were removed in vacuo to afford a solid. The solid was dissolved in water and the pH was raised to 10, and the solution was extracted twice with ethyl ether. The combined ether extracts were washed twice with brine and dried over sodium sulfate. Removal of the ether solvent afforded 85.5 grams (98.8%) of (4-bromo-phenyl)-methyl-amine. The spectral properties of the oil were consistent with the desired material. High performance liquid chromatography (“HPLC”) analysis revealed that the oil was greater than 95% of 4-bromophenyl-N-methylaniline. This material was used in the next step without purification. Step (3): 7-Bromo-4-methyl-1,1-dioxo-1,4-dihydro-2H-1l6-benzo[1,2,4]thiadiazin-3-one

1. customdid not rise above 5° C
2. temperatureto reflux
3. customthe frothing of the reaction
4. customThen hydrogen chloride gas was bubbled into the solution until the pH was approximately 2
5. customThe solvents were removed in vacuo
6. customto afford a solid
7. temperaturethe pH was raised to 10
8. extractionthe solution was extracted twice with ethyl ether
9. washThe combined ether extracts were washed twice with brine
10. dry with materialdried over sodium sulfate
11. customRemoval of the ether solvent

ORD-Eintrag

ord-e462c1977bce43a4bac2c8b20448c664

Quelldatensatz

uspto-grants-2005_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06849648B2