1-Adamantyl Chlorocarbonate [1]

Abstract

A solution of 1-hydroxyadamantane [2] (15.2 g, 100 mmol) in dry benzene (400 ml) and pyridine (1 ml) is stirred and cooled in an ice-water bath. A solution of phosgene [3] (45 g, ca 450 mmol) in dry benzene (150 ml) is added, dropwise, at about 4 °C for about one hour. When a white solid separates, more benzene is added. After one hour at room temperature the mixture is filtered, the filtrate is poured onto cracked ice, the organic layer separated and dried over anhydrous Na₂SO₄. The solution is concentrated in vacuo to about one-fifth of its original volume and stored in a freezer. For most practical purposes this solution can be used; the yield is assumed to be quantitative. An aliquot of the solution evaporated to dryness in vacuo leaves a residue melting at about 42 °C. Recrystallization from dry petroleum ether (b.p. 30–60 °C) affords the chlorocarbonate in purified form, melting at 46–47 °C.