| abstract |
5-Chloro-toluene- 2,4-di-isocyanate and 3-chloro-toluene- 2,6-di-isocyanate or chloro-toluene-di-isocyanate contg. both isomers are prepd. from the appropriate toluene-di-isocyanate by selective chlorination with chlorine gas without catalyst and without solvent at 20-120 deg.C using a chlorine gas feed rate changing during the reaction between 2-12 litre per hr. Resulting chloro-toluene-di-isocyanate is transformed with aq. alkali soln. of 5-40 wt.% conc. opt. contg. emulsifier at 0-50 deg.C into carbaminic-acid-sodium salts which are in turn hydrolysed at 50-100 deg.C to diamino-chloro-toluene. |