反应详情

A process according to claim 1, wherein the compound of formula II is reacted with ethylene carbonate in the presence of a catalytic amount of tributylamine at a temperature between +130° C. and +150° C.; the resulting reaction mixture is treated with phosgene in the presence of a catalytic amount of dimethylformamide at a temperature between +70° C. and +90° C. yielding the compound of formula IV, which after purification is treated with 1 equivalent of chlorosulfonic acid or with a slight excess thereof in cyclohexane or n-decane at a temperature between +20° C. and +60° C.; neutralized with aqueous sodium hydroxide at a temperature between +50° C. and +90° C.; dechlorinated with hydrogen in the presence of an acid acceptor, in the pressure range from 1 to 5 bar at a temperature between +20° C. and +70° C. and in the presence of a 5% palladium on carbon catalyst; converted to the sulfonic acid chloride by treatment of the mixture with phosgene at a temperature between +60° C. and +120° C.; and subsequently reacted to the final product by treatment of the reaction mixture with an aqueous solution of ammonia.

1. customafter purification
2. customat a temperature between +20° C. and +60° C.