Formaldehyde → 3-[5-(benzyloxy)-2-hydroxyphenyl]-1-[(5-chloro-2-thienyl)methyl]-3-hydroxymethyl-1,3-dihydro-2H-indol-2-one

Participants

Reaction Steps

To a mixture of 3-[5-(benzyloxy)-2-hydroxyphenyl]-1-[(5-chlorothiophen-2-yl)methyl]-1,3-dihydro-2H-indol-2-one (2.80 g, 6.07 mmol), para-formaldehyde (0.73 g, 24.3 mmol) in tetrahydrofuran (10.0 mL) was added an aqueous solution of sodium hydroxide (0.97 g, 24.3 mmol) in water (10.0 mL) at 0° C. The reaction solution was stirred for 2 h, then quenched by the addition of 10% aqueous hydrochloric acid solution (30.0 mL). The reaction mixture was extracted with ethyl acetate (3×50 mL). The combined organic solution was washed with saturated ammonium chloride (3×50 mL), brine (50.0 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was triturated with diethyl ether, filtered and dried to afford 3-[5-(benzyloxy)-2-hydroxyphenyl]-1-[(5-chlorothiphen-2-yl)methyl]3-(hydroxymethyl)-1,3-dihydro-2H-indol-2-one (2.71 g, 91%) as a colourless solid: MS (ES+) m/z 494.2 (M+1), 492.3 (M+1).

Provenance & Evidence