The importance of some thiol-carbamic esters, in the agricultural field, is well known to the skilled in the art, and equally known are the technological difficulties which arise in their preparation. The methods and processes adopted at present require in fact the use of very unpleasant reagents, being poisonous, bad smelling, expensive and causing pollution, such as phosgene, carbonyl sulphide, ethyl mercaptan, metallic sodium, ethyl chlorothiolformate, and require the use of installations which are always complex, costly and generally undesired for ecological purposes.
It is thus easy to understand why searches are being carried out with such interest and intenseness, for the purpose of saving the production of thiolcarbamates from such a precarious situation.
In the sphere of such searches, the present invention provides a fully satisfactory solution of the problem, starting from the consideration that the thiol-carbamic esters can be obtained by isomerization of corresponding thion-carbamic esters, and providing for original and particularly simple and efficient methods both for obtaining the thioncarbamates and for their isomerization into thiolcarbamates.
USPTO Backgrounds
USPTO Backgrounds