Nitric Acid → 3H-Indole, 2,3,3-trimethyl-5-nitro-
Reaction equation
[CH3:1][C:2]1[C:10]([CH3:12])([CH3:11])[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[N:3]=1.[N+:13]([O-])([OH:15])=[O:14]>S(=O)(=O)(O)O>[N+:13]([C:7]1[CH:8]=[C:9]2[C:4](=[CH:5][CH:6]=1)[N:3]=[C:2]([CH3:1])[C:10]2([CH3:12])[CH3:11])([O-:15])=[O:14]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
5-nitro-2,3,3-trimethylindole (1) was synthesized according to a modified literature procedure (see, Noland, W. E., et al., J. Org. Chem. 3457-3469, 1965). To a solution of 2,3,3-trimethylindole (10.6 g) in concentrated sulfuric acid cooled to 0° C. using an ice/brine bath was added dropwise fuming nitric acid (5.6 mL). The resultant solution was stirred at 0° C. for 1.5 hours; then poured into crushed ice; filtered; and washed with water. The combined filtrate was neutralized to a pH greater than 7. The product precipitated from the neutralized solution and was collected by filtration, washed with water, and dried to provide the desired product 1 (10.1 g, 74% yield): ESI-MS, calculated [M+H]+ 205.1, found 205.0.