Chlorosulfonic acid → 4-Chlorosulfonyl-3-isopropyl-5-methylphenoxyacetic acid 2-(toluene-4-sulfonyl)ethyl ester

関与物質

反応条件

反応手順

To a mixture of 3-isopropyl-5-methylphenoxyacetic acid 2-(toluene-4-sulfonyl)ethyl ester (Intermediate 64, 5.5 g, 14.0 mmol) and 4 mL of CH2Cl2 was added dropwise chlorosulfonic acid (8.2 g, 70.0 mmol, 5.0 eq) with ice-bath cooling. The mixture was stirred at 0° C. for 3 h. The resulting thick oil was poured onto crushed ice with vigorous stirring. The mixture was extracted with EtOAc. The organic layer was washed with 1 N NaHCO3 solution, dried over MgSO4, and concentrated by evaporation to give crude product 4-chlorosulfonyl-3-isopropyl-5-methylphenoxyacetic acid 2-(toluene-4-sulfonyl)ethyl ester (Intermediate 65, 6.0 g, 87%) as light brown thick oil, which was purified by silica gel column chromatography.

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