反应详情

The procedure as in Example 27, a was followed using 4-(5-bromo-6-chloro-pyridine-3-sulfonyl)-5-nitro-thiophene-2-carboxylic acid methyl ester (3.5 g, 8.10 mmol, Example 118, step b) and sodium thiomethoxide (560 mg, 8.10 mmol as 1M solution in EtOH). The reaction was allowed to stir for 2.5 hours and was quenched with acetic acid. The resulting mixture was dissolved into EtOAc, and aqueous work up with brine and saturated NaHCO3 resulted in isolation of a mixture. This mixture was purified by SiO2 flash column chromatography (Biotage—40 M, 100% hexanes to 25% EtOAc in hexanes). The product was isolated as a yellow solid (750 mg, 21%). ESI-MS (m/z): Calcd. for C12H10BrClNO4S3: 441.8 (M+H); found: 442.1. 1H-NMR (CD3OD+CDCl3): δ 8.93 (m, 1H), 8.50 (m, 1H), 8.06 (s, 1H), 3.91 (m, 3H), 2.67 (m, 3H).

1. customwas quenched with acetic acid
2. dissolutionThe resulting mixture was dissolved into EtOAc, and aqueous work up with brine and saturated NaHCO3
3. customresulted in isolation of a mixture
4. customThis mixture was purified by SiO2 flash column chromatography (Biotage—40 M, 100% hexanes to 25% EtOAc in hexanes)