[H-].[Na+].NC1NC2C(C=1C#N)=CC=C([N+]([O-])=[O:16])C=2.I[CH2:19][CH3:20].[NH2:21][C:22]1[N:23]([CH2:36][CH3:37])[C:24]2[C:29]([C:30]=1[C:31]#[N:32])=[CH:28][CH:27]=[C:26]([N+:33]([O-:35])=[O:34])[CH:25]=2>CCCCCC.CS(C)=O.CCOC(C)=O>[C:31]([C:30]1[C:29]2[C:24](=[CH:25][C:26]([N+:33]([O-:35])=[O:34])=[CH:27][CH:28]=2)[N:23]([CH2:36][CH3:37])[C:22]=1[NH:21][C:19](=[O:16])[CH3:20])#[N:32]Sodium hydride (42 mg, 1.05 mmol, 60% w/w suspension in mineral oil) is washed with hexane and taken up in dimethylsulfoxide (1 mL). A solution of 2-amino-6-nitro-1H-indole-3-carbonitrile (prepared in procedure 1T) in dimethylsulfoxide (1 mL) is added by syringe, and the resulting mixture is stirred for 20 min. Then, iodoethane (77 μL, 0.96 mmol) is added by syringe, and the mixture is stirred for 14 h. The reaction is then poured into EtOAc (50 mL), and this solution is washed with water (3×50 mL) and saturated brine (40 mL). The aqueous phases are back-extracted with EtOAc, and the organic extracts are combined, dried over Na2SO4, filtered and evaporated. The residual material is separated by column chromatography over silica gel (EtOAc/hexanes, 1/1) to afford first a small amount of a dialkylated analog, then the desired compound, 2-amino-1-ethyl-6-nitro-1H-indole-3-carbonitrile (114 mg, 52%), and finally unreacted starting material. The desired product is isolated as an orange powder.
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