Phosphorus oxychloride → 2,3-Dioxoindoline-5-sulfonyl chloride

A suspension of sodium 2,3-dioxoindoline-5-sulfonate dihydrate (5.0 g, 17.53 mmol) and POCl3 (8.17 ml, 88 mmol) in sulfolane (25 ml, 264 mmol) was heated at 60° C. for 3 hours. The solution was cooled to 0° C. and water (60 ml) was added drop wise; the green precipitate was filtered and washed with a small amount of water. The solid was dissolved in ethyl acetate and washed three times with water; the organic phase was then dried over sodium sulfate and evaporated to give a crude solid that was purified by crystallization from hexane/ethyl acetate 1:1 to give 2,3-dioxoindoline-5-sulfonyl chloride (3.52 g, 14.33 mmol, 82% yield).

1. temperatureThe solution was cooled to 0° C.
2. filtrationthe green precipitate was filtered
3. washwashed with a small amount of water
4. dissolutionThe solid was dissolved in ethyl acetate
5. washwashed three times with water
6. dry with materialthe organic phase was then dried over sodium sulfate
7. customevaporated
8. customto give a crude solid that
9. customwas purified by crystallization from hexane/ethyl acetate 1:1

ORD record

ord-82bea943c6264cb68bb06a22af1cd06c

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09024027B2