Sulfuric Acid → 2,3,4,5-Tetrahydro-8-iodo-2-methyl-1h-pyrido[4,3-b]indole

Participants

Reaction Conditions

Reaction Steps

To a solution of compound 4-iodophenylhydrazine (1 equiv.) in 1,4-dioxane (50 mL) is added conc. sulfuric acid, followed by dropwise addition of 1-methyl-4-piperidone (1 equiv.) at RT. The reaction mixture is heated at 70° C. for 90 min., evaporated, diluted with water and the pH is adjusted to 12 with 40 mL of 15% aq. KOH solution. The reaction mixture is extracted with EtOAc, followed by brine wash, dried over sodium sulfate and evaporated under vacuum. The crude product is column purified over 230-400 silica gel using a gradient of 0-5% of MeOH in EtOAc. Note 1: The reaction temperature should be 70° C. Higher temperature results in the de-iodo carboline.

Provenance & Evidence