反应详情

A solution of 4.76 g (20.6 mmol) of the product of Step A in 140 mL of methanesulfonic acid was immersed in an ice-water bath (temperature between 5°-10° C.). Then, 4.0 g (24.6 mmol) of 2-bromothiophene was added dropwise. It was stirred at the same temperature until a deep blue-black color formed. It was poured into ice-water and the resulting precipitate was filtered. The solid was triturated with methylene chloride to give 4.05 g of a tan solid: mp 198°-199° C. (dec.). 1H-NMR (DMSO-d6) δ9.80 (d,1H), 7.55 (m, 1H), 7.20 (m,3H), 7.00 (d, 1H), 5.80 (d, 1H).

1. custom(temperature between 5°-10° C.)
2. customformed
3. filtrationthe resulting precipitate was filtered
4. customThe solid was triturated with methylene chloride