Nitric Acid → 3,7-Dimethyl-5-nitrobenzo[d]isoxazole

3,7-dimethylbenzo[d]isoxazole (Step 46.4) (2 g, 12.77 mmol) was dissolved in H2SO4 (5 mL), cooled down and stirred at 0° C. HNO3 (0.878 mL, 12.77 mmol) was slowly added and the resulting mixture was stirred at 0° C. for 1 hr. The reaction was diluted with water (60 mL) and extracted three times with CH2Cl2. The combined organic layers were washed with NaHCO3 solution and brine, dried over MgSO4, filtered and concentrated under reduced pressure. The resulting yellow solid was triturated with Et2O, filtrated off, washed with Et2O and dried to afford the title product (1.86 g, 9.29 mmol, 73% yield) as yellow solid. tR: 0.98 min (LC-MS 2); ESI-MS: 193 [M+H]+.

1. temperaturecooled down
2. stirringthe resulting mixture was stirred at 0° C. for 1 hr
3. extractionextracted three times with CH2Cl2
4. washThe combined organic layers were washed with NaHCO3 solution and brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe resulting yellow solid was triturated with Et2O
9. filtrationfiltrated off
10. washwashed with Et2O
11. customdried

ORD-Eintrag

ord-963bb350aab54975a84f4751c4ba04f5

Quelldatensatz

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08975417B2