Abstract: The invention provides compounds of the general formula ##STR1## wherein R represents a hydrogen atom, or an optionally substituted alkyl or acyl group, or an alkenyl or alkynyl group or an inorganic or organic cation;R.sup.1 represents an alkyl, haloalkyl, alkenyl, alkynyl or phenyl group;R.sup.2 represents an optionally substituted alkyl or phenalkyl group or a cycloalkyl, alkenyl, haloalkenyl, alkynyl or haloalkynyl group;R.sup.3 represents a hydrogen atom or an alkyl group; andone of R.sub.4 and R.sup.5 represents a hydrogen atom or an alkyl group, while the other of R.sup.4 and R.sup.5 represents an optionally substituted phenyl group; together with their use as herbicides and their preparation using novel intermediates.

Abstract: The invention provides benzothiazinone derivatives of formula ##STR1## wherein R.sub.1 represents a nitrogen-containing heteroaromatic group or a phenyl group substituted by 1 or 2 substituents selected from halogen atoms, alkyl, haloalkyl and alkoxy groups; a process for the preparation of such compounds; compositions containing them and a method of combating plant pathogenic fungi using such compositions or compounds.