Methyl iodide → 3,6-dibromo-9-methyl-9H-carbazole

Participants

Reaction Steps

4-Bromo-1H-thieno[3,4-d]imidazol-2(3H)-one represented by formula (5a) was obtained in the same manner as in Example 1. In 3 ml/mmol of tetrahydrofuran to 3,6-dibromo-9H-carbazole, it was reacted with 1.1 equivalents of sodium hydride for 1 hour under argon gas atmosphere while being kept at 0° C. in an ice bath, and then 1.2 equivalents of methyl iodide was added and a reaction was further continued for 4 hours at room temperature. The reaction was stopped by adding an excessive amount of a mixed aqueous solution of ion-exchange water:ammonium chloride=3:1. The product was extracted from the resulting reaction liquid to an organic layer using diethyl ether and dried over sodium sulfate and then the solvent was evaporated, followed by a purification step by column separation using an ethyl acetate/hexane solvent, so that 3,6-dibromo-9-methyl-9H-carbazole was obtained.

Provenance & Evidence