Yield:875781-44-5 100%

Reaction Conditions:

with N-iodo-succinimide in N,N-dimethyl-formamide at 20; for 1 h;

Steps:

333.1 Step 1. 2-Bromo-7-iodo-5H-pyrrolo[2,3-b]pyrazine
Step 1. 2-Bromo-7-iodo-5H-pyrrolo[2,3-b]pyrazine. To a solution of 2-bromo-5H-pyrrolo[2,3-b]pyrazine (8 g, 40.4 mmol) in DMF (160 mL) was added N-iodosuccinimide (11.8 g, 3.6 mmol) at room temperature, and stirred for 1 h. TLC (Petroleum ether: EtOAc, 2:1) indicated the reaction was completed. reaction mixture was diluted with water (500 mL), and extracted with EtOAc (300 mL×3). The combined organic layers were washed with brine, and dried over Na₂SO₄. After filtration, the solvent was removed under reduced pressure to give 2-bromo-7-iodo-5H-pyrrolo[2,3-b]pyrazine (26.1 g, 100%) as brown solid (containing some DMF).

References:

Thorarensen, Atli;Brown, Matthew Frank;Casimiro-Garcia, Agustin;Che, Ye;Coe, Jotham Wadsworth;Flanagan, Mark Edward;Gilbert, Adam Matthew;Hayward, Matthew Merrill;Langille, Jonathan David;Montgomery, Justin Ian;Telliez, Jean-Baptiste;Unwalla, Rayomand Jal US2015/158864, 2015, A1 Location in patent:Paragraph 0645

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