Sulfuric Acid → 2,3-Dimethyl-6-nitro-2H-indazole

Temperature

50 °C

3-methyl-6-nitro-2H-indazole (0.85 g, 5 mmol, 1 equiv) was dissolved in DMSO (4 ml) and treated with sulphuric acid (0.26 ml, 5 mmol, 1 equiv) to yield a thick slurry that was treated with dimethylsulfate (1.36 ml, 14 mmol, 2.8 equiv). The reaction mixture was heated to 50° C. under nitrogen for 72 hrs. The reaction mixture was cooled down to room temperature and treated with a saturated solution of sodium bicarbonate (10 ml). The reaction mixture was extracted with DCM (2×20 ml). The organic layers were washed with water (20 ml). Propanol was added and the organic layers were evaporated under vacuum to yield a solid which was filtered and washed with heptane (5 ml). The desired compound was collected as a brown solid (0.48 g, 50%).

1. customto yield a thick slurry that
2. temperatureThe reaction mixture was cooled down to room temperature
3. extractionThe reaction mixture was extracted with DCM (2×20 ml)
4. washThe organic layers were washed with water (20 ml)
5. additionPropanol was added
6. customthe organic layers were evaporated under vacuum
7. customto yield a solid which
8. filtrationwas filtered
9. washwashed with heptane (5 ml)
10. customThe desired compound was collected as a brown solid (0.48 g, 50%)

ORD record

ord-b660f15113aa45d3bd784542981071d5

Source dataset

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08349861B2