反应详情

7-Nitro indole (1 eq.) and oxalyl dichloride (10 eq.) were mixed in ether or CH2Cl2. The reaction was stirred for 24 hours and 2-(7-nitro-1H-indol-3-yl)-2-oxoacetyl chloride precipitated from solution. Filtration offered yellow solid which was dried under vacuum and used in Step 2 without purification. Step 2: iPr2NEt (1-10 eq.) was added into a solution of 2-(7-nitro-1H-indol-3-yl)-2-oxoacetyl chloride from Step 1 and amine (1 eq.) in THF, dioxane or CH2Cl2. The reaction was stirred at room temperature for 24 hours, before being quenched with NaHCO3 (equal volume to THF, dioxane or CH2Cl2 used). The aqueous phase was extracted with EtOAc (3× equal volume to THF, dioxane or CH2Cl2 used). The combined organic phase was dried over MgSO4, filtered and concentrated under vacuum to give a crude product, nitro indole 2-oxoacetyl amide, which was used without purification in the Step 3.

1. custom2-(7-nitro-1H-indol-3-yl)-2-oxoacetyl chloride precipitated from solution
2. filtrationFiltration
3. customwas dried under vacuum
4. customused in Step 2 without purification
5. stirringThe reaction was stirred at room temperature for 24 hours
6. custombefore being quenched with NaHCO3 (equal volume to THF, dioxane or CH2Cl2 used)
7. extractionThe aqueous phase was extracted with EtOAc (3× equal volume to THF, dioxane or CH2Cl2 used)
8. dry with materialThe combined organic phase was dried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated under vacuum