Potassium Iodide → Tiospirone

Participants

Reaction Steps

Method A--A mixture of 3-(1-piperazinyl)-1,2-benzisothiazole (24.3 g., 0.11 mole) and 8-(4-bromobutyl)-8-azaspiro[4.5]decane-7.9-dione (33.5 g., 0.11 mole), anhydrous potassium carbonate (32.4 g., 0.23 mole) and potassium iodide (3.9 g., 0.023 mole) in 1 liter of acetonitrile is stirred and heated under reflux for a period of 20 hr. The reaction mixture is filtered, concentrated in vacuo and residual material taken up in 350 ml. of chloroform which is filtered and concentrated in vacuo. The residue is triturated with ether, refrigerated and resulting solid collected. This material crystallized from acetonitrile (employing activated charcoal affords a first crop 25.1 g, m.p. 120°-124° C. and a second crop, 6.0 g, m.p. 123°-126° C. for a total yield of 31.1 g. (64% yield) of the free base form of the title compound. Crystallization from acetonitrile affords analytically pure 8-[4-[ 4-(1,2-benzisothiazol-3-yl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione, m.p. 124°-126° C.

Provenance & Evidence