Diethyl Ether → 4-Isocyanato-5,6-dihydro-1-benzothiophen-7(4H)-one

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Reaction Steps

A solution of 4,5,6,7-tetrahydro-7-oxobenzo[b]thien-4-ylisocyanide (9.5 g) in dry dimethylsulfoxide (4.63 g) is stirred under a nitrogen atmosphere while anhydrous p-toluenesulfonic acid (0.93 g) is added in small portions over an hour. The mixture is heated below 50° C. After 1.25 hours the reaction mixture is cooled and ether (3 × 3 ml) added, and the ether solution is then decanted. The ether solution contains the title isocyanate, and is used as is.

Provenance & Evidence