Process for preparation of aliphatic primary sulfamates

#The present invention relates to a process for the preparation of aliphatic primary sulfamates. The sulfamates which can be prepared by the present process may be represented by the formula: ##STR1## WHEREIN N IS AN INTEGER FROM 0-8 AND X and Y are hydrogen, provided that when n is 1, X and Y are either hydrogen, lower alkyl having 1-3 carbon atoms, aryl such as phenyl or arylalkyl such as benzyl, phenethyl and the like.

#The aliphatic primary sulfamates of the present invention are prepared by reacting an alkanediol with a substituted sulfamoyl halide such as a substituted sulfamoyl chloride, for example, in a suitable solvent in the presence of a strong base. Suitable alkanediols which may be employed include 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,10-decanediol and the like. As the halide reactant, a substituted sulfamoyl halide is employed wherein the substituent is a protecting group which can be readily removed under acid conditions. Suitable groups which may be employed include groups such as t-butyl, benzyl, .alpha.-alkyl benzyl wherein the alkyl group has 1-3 carbon atoms, allyl and 1-alkyl-allyl wherein the alkyl group has 1-3 carbon atoms. The substituent on the sulfamoyl halide reactant is removed by treating the compound obtained from the reaction mixture with a strong acid. Acids such as trichloroacetic acid, trifluoroacetic acid, methanesulfonic acid, conc. sulfuric acid and conc. hydrochloric acid, for example, may be employed. The preparation of unsubstituted sulfamoyl halides involves steps which are inherently hazardous. The use of a substituted sulfamoyl halide in place of an unsubstituted sulfamoyl halide avoids the hazards associated with the preparation of sulfamoyl halides. Substituted sulfamoyl halides are prepared by reacting an appropriate amine such as, for example, t-butylamine or benzylamine, with a sulfuryl halide in a suitable solvent, such as acetonitrile, for example. Bases such as sodium hydride, potassium t-butoxide, potassium hydride, tributyltin, sodium amide and sodium are examples of bases which may be employed for the initial reaction. Suitable solvents for the reaction include toluene, benzene, xylene, ether, tetrahydrofuran, diglyme, 1,2-dimethoxyethane and p-dioxane.

#The reaction with the substituted sulfamoyl halide may be carried out at room temperature, but it is preferred to carry out the reaction at a temperature between room temperature and about 60.degree. C. The removal of the protecting group is preferably carried out at room temperature in an inert atmosphere such as nitrogen, for example. The product is obtained from the reaction mixture by techniques known to those skilled in the art.