PURPOSE: To provide an economical process for producing a dicarbonate in a short reaction time in high yield.
CONSTITUTION: Di-t-butyl dicarbonate is produced by reacting an alkali metal (preferably Na) mono-t-butyl carbonate with an aromatic sulfonyl halide (e.g. p-toluenesulfonyl chloride) in the presence of a t-amine (e.g. triethylamine, N,N- dimethylaniline and pyridine) and dimethyl sulfoxide at -50 to +100°C (preferably 0-50°C). Preferably, the amount of the aromatic sulfonyl halide is 0.3-0.5 times mol, that of the t-amine is 0.001-20mol% (especially 0.05-10mol%) and that of dimethyl sulfoxide is 30-100mol% based on the t-butyl carbonate salt. The di-t-butyl dicarbonate is useful as an agent for introducing a protecting group to protect an amino group by tert-butoxycarbonylation.
HAGIWARA ISAO
OKUDA NORIKAZU
Next Patent: SEPARATION OF METHANOL FROM DIMETHYL CARBONATE/ METHANOL MIXTURE