Hoechst Aktiengesellschaft

Hoechst Schering Agrevo Gmbh

Gunter Schlegel

Lothar Willms

Heinz Kehne

Hilmar Mildenberger

Stephen Lachhein

Harald Knorr

Herbert Stark

Harald Berger

Stephen Lacchein

Compounds of the formula I or salts thereof, in which

Processes for preparing sulfonylureas

Processes for preparing sulfonylureas Compounds of the formula I or salts thereof, ##STR1## in which X is oxygen, --O--NR.sup.2 -- or --SO.sub.2 --NR.sup.2 --, and Y is N or CH,

The title compounds are obtained by racemate resolution of D,L-homoalanin-4-yl(methyl)phosphinic acid via precipitation of one of the diastereomeric salts using chiral bases such as quinine or cinchonine. It is possible to increase the yield of desired enantiomer by transformed racemate resolution when the precipitation of the diastereomeric salt takes place with the racemization of the undesired enantiomer in the presence of (hetero)--aromatic aldehydes. The racemization method is also suitable for structurally different optically active amino acids.

Processes for preparing �L!- or �D!-homoalanin-4-yl-(methyl) phosphinic

Processes for preparing �L!- or �D!-homoalanin-4-yl-(methyl)phosphinic acid and salts thereof by racemate resolution The title compounds are obtained by racemate resolution of D,L-homoalanin-4-yl (methyl)phosphinic acid via precipitation of one of the diastereomeric salts using chiral bases such as quinine or cinchonine. It is possible to increase the yield of desired enantiomer by transformed racemate resolution when the precipitation of the diastereomeric salt takes place with the racemization of the undesired enantiomer in the presence of (hetero)aromatic aldehydes. The racemization method is also suitable for structurally different optically active amino acids.

Processes for preparing �L!- or �D!-homoalanin-4-yl-(methyl)phosphinic

Process for the preparation of sulfonylureas Herbicidal sulfonylureas of the formula I, ##STR1## in which X is --O--, --0--NR.sup.2 -- or --SO.sub.2 --NR.sup.2 --, Y is --N-- or CH,

Process for the preparation of sulfonylureas

Herbicidal sulfonylureas of the formula I, ##STR1## in which X is --O--, --O--NR.sup.2 -- or --SO.sub.2 --NR.sup.2 --, Y is --N-- or CH,

A compound of formula I or salt thereof can be prepared in a process which comprises reacting a compound of formula II with a compound of formula III: ##STR1## wherein the formulae I-III the radical X is O, ONR.sup.2 or SO.sub.2 NR.sup.2 ; Y is N or CH;

Compounds of the formula I or salts thereof, ##STR1## in which X is oxygen, --O--NR.sup.2 -- or --SO.sub.2 --NR.sup.2 --, and Y is N or CH,

The invention relates to an improved process for the preparation of a compound of the formula R.sup.1 -X-SO.sub.2 -NCO in which

Continuous process for the preparation of sulfonylisocyanates

Process for the preparation of D(+)-2-(4-acetylphenoxy)-propionic esters Preparation of D(+)-2-(4-acetylphenoxy)-propionic esters of the formula ##STR1## by reacting 4-hydroxyacetophenone with L-halo- or sulfonyloxy-lactic esters in a basic medium at temperatures .ltoreq.50.degree. C.

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Liederbach, Germany

Gunter Schlegel