Basf Aktiengesellschaft

Fritz Zanker

Norbert Goetz

Bjoern Girgensohn

Rainer Ohlinger

N-(3,5-Dichlorophenyl)-oxazolidine-2,4-diones of the formula ##STR1## where R.sup.1 is haloalkenyl, alkenyl, chloromethyl, CN, CO--O-alkyl, alkoxyalkyl or alkylthioalkyl and R.sup.2 is haloalkenyl, alkenyl, hydrogen or alkyl, are prepared by a process in which 3,5-dichlorophenyl isocyanate is reacted with a glycolate of the formula ##STR2## where R.sup.1 and R.sup.2 have the above meanings and R.sup.3 is alkyl or cyclohexyl, in the presence of a tin(II) salt of the formula ##STR3## where R.sup.4 and R.sup.5 are identical or different and are each hydrogen, alkyl, alkenyl or unsubstituted or alkyl-substituted cycloalkyl, or benzyl or phenyl, or R.sup.4 and R.sup.5 together form --CH.sub.2 --CH.sub.2 --, --CH.dbd.CH-- or o-phenylene, at from 0.degree. to 110.degree. C., the product is heated in the presence of an alcohol of the formula

Preparation of N-(3,5-dichlorophenyl)oxazolidine-2,4-diones

2,6-Dimethylmorpholine containing a high proportion of the cis compound is prepared by cyclization of diisopropanolamine (1,1'-iminobispropan-2-ol) in the presence of sulfuric acid, with simultaneous addition of the components and full utilization of the heat of reaction.

Preparation of cis-2,6-dimethylmorpholine

Aliphatic and cycloaliphatic isocyanates are manufactured by thermal decomposition of aliphatic or cycloaliphatic carbamic acid chlorides in the presence of an inert organic solvent of lower boiling point than that of the isocyanate formed. The decomposition is carried out in a reaction vessel surmounted by a rectifying unit, which in turn is surmounted by a reflux condenser, the isocyanate formed being condensed in the rectifying unit at a temperature above the boiling point of the solvent.

Manufacture of aliphatic or cycloaliphatic isocyanates

A process for the manufacture of aliphatic isocyanates by thermal decomposition of aliphatic carbamic acid halides. The decomposition is carried out in stages and the hydrogen halide liberated is expelled, in the first stage, without passing inert gas through the reaction mixture, while in the second stage it is expelled while passing an inert gas, which is recycled, through the reaction mixture.

Manufacture of aliphatic isocyanates

Aliphatic isocyanates are manufactured by thermal decomposition of aliphatic carbamic acid halides, an inert gas being passed in during the decomposition and being removed together with the hydrogen halide formed. The isocyanates which may be manufactured by the process of the invention, particularly ethyl isocyanate, n-propyl isocyanate and isopropyl isocyanate, are valuable starting materials for the manufacture of plant protection agents, pesticides, dyes, synthetic resins, plastics, hydrophobic agents for textiles, detergents, bleaches and adhesives.

Growing community of inventors

Worms, Germany

Fritz Zanker