2.
    发明专利
    未知

    公开(公告)号:DE59003627D1

    公开(公告)日:1994-01-05

    申请号:DE59003627

    申请日:1990-10-31

    Applicant: DEGUSSA

    Abstract: Alkyl isothiocyanates of the formula R-N=C=S can be prepared by reaction of N-alkyldithiocarbamates with hydrogen peroxide in aqueous phase at 95 to 130 DEG C. According to the invention, the aqueous N-alkyldithiocarbamate solution is made to react with a 20 to 40% strength by weight aqueous hydrogen peroxide solution in a volume ratio of 1 to 0.8 to 1, while maintaining a pH of 1.5 to 4.5. Preferably, the solutions are sprayed into a reactor in which the alkyl isothiocyanate formed is distilled off in vapour form and the aqueous phase containing the by-products accumulates in the reactor. The process according to the invention makes it possible to increase the space-time yield significantly because compared with the prior art process which is carried out at pH 5 to 9 a much smaller amount of sulphur is formed, thus minimising the shutdown times for the cleaning of the reactor.

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