Societe Nationale Des Poudres Et Explosifs

Julien C Deweerdt

Jean-Pierre G Senet

Denis Souyri

Jacques Sala

According to the invention, phosgene is reacted with a mercaptan in the presence of a catalyst of the general formula: ##STR1## in which X=O or S and in which R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are, in particular, aliphatic, cycloaliphatic or aromatic groups or a hydrogen atom. The proportion of catalyst is 0.1 to 10 mol %, relative to the mercaptan, and the reaction is carried out at ambient temperature and at atmospheric pressure. The process, which can be made continuous, results in short residence times and in a high yield and a high purity. Thiochloroformates are applied essentially as intermediates for the synthesis of herbicidal compounds.

Process for the manufacture of thiochlorformates

Hydroxy-telechelating oligomers of number average molecular weight 250 to 2,500 and containing carbonate groups, are prepared by first polycondensing a bis-chloroformate with a diol at a temperature below 150.degree.C and at a moderately reduced pressure while flushing the reaction mixture with an inert anhydrous gas, and then the oligomers formed are dissolved in a volatile, water-immiscible organic solvent and the solution washed with an aqueous base solution. In this way, oligomers may be prepared which have a low or zero sensitivity to water, are non-acidic and relatively inexpensive.

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Toulouse, France

Julien C Deweerdt