Thionyl Chloride → 5-Chloro-N-hydroxy-N-(1-methylethyl)-3-(trimethylsilyl)-2-thiophenecarboxamide

Participants

Reaction Steps

5-Chloro-3-(trimethylsilyl)-2-thiophenecarboxylic acid chloride was prepared by the reaction of 1 g 5-chloro-3-(trimethylsilyl)-2-thiophenecarboxylic acid (prepared as in Example 263) and 6 mL thionyl chloride, using the procedure of step a in Example 248. This product was dissolved in CH2Cl2 at 0° C. and added to a mixture of N-isopropylhydroxylamine hydrochloride (0.55 g, 5 mmol) and 4 g NaHCO3 in 20 mL CH2Cl2 and 20 mL water. The resulting reaction mixture was stirred at RT for additional 3 h. The organic layer was separated, washed with brine, dried and concentrated. The residue was purified by flash chromatography with 8% ethyl acetate/hexane to give 80 mg of the title compound. m.p. 146°-150° C.

Provenance & Evidence