Process for the production of 5-hydroxyoxazolidinones

A process for the production of a hydroxyoxazolidinone of formula I:

• ##STR13## wherein A is phenyl optionally substituted by one or more substituents selected from halogen, C.sub.1 -C.sub.10 hydrocarbyl, S(O).sub.p (C.sub.1 -C.sub.10 hydrocarbyl), cyano, nitro, SCN, SiR.sup.c.sub.3 (where each R.sup.c is independently C.sub.1 -C.sub.4 alkyl or phenyl), COR.sup.12, CR.sup.12 NOR.sup.13, ONR.sup.12 R.sup.13, SF.sub.5, COOR.sup.12, SO.sub.2 NR.sup.12 R.sup.13, OR.sup.14 or NR.sup.15 R.sup.16 ;
• alternatively, two substituents may combine to form a fused 5- or 6-membered saturated or partially saturated carbocyclic or heterocyclic ring in which any carbon or quaternised nitrogen atom may be substituted with any of the groups mentioned as substituents on A, a ring carbon atom may form part of a carbonyl group or a nitrogen atom may be oxidised;
• p is 0, 1 or 2;
• R.sup.12 and R.sup.13 independently represent hydrogen or C.sub.1 -C.sub.10 hydrocarbyl;
• R.sup.14 is hydrogen, C.sub.1 -C.sub.10 hydrocarbyl, SO.sub.2 (C.sub.1 -C.sub.10 hydrocarbyl), CHO, CO(C.sub.1 -C.sub.10 hydrocarbyl), COO(C.sub.1 -C.sub.10 hydrocarbyl) or CONR.sup.12 R.sup.13 ;
• R.sup.15 and R.sup.16 independently represent hydrogen, C.sub.1 -C.sub.10 hydrocarbyl, O(C.sub.1 -C.sub.10 hydrocarbyl), SO.sub.2 (C.sub.1 -C.sub.10 hydrocarbyl), CHO, CO(C.sub.1 -C.sub.10 hydrocarbyl), COO(C.sub.1 -C.sub.10 hydrocarbyl) or CONR.sup.12 R.sup.3 ;
• and
• any of the foregoing hydrocarbyl groups, whether the hydrocarbyl group is a group on its own or part of a larger group, may optionally be substituted with halogen, hydroxy, SO.sub.2 NR.sup.a R.sup.b (where R.sup.a and R.sup.b independently represent hydrogen or C.sub.1 -C.sub.6 alkyl), cyano, nitro, amino, mono- or di-C.sub.1 -C.sub.6 alkylamino, acylamino, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.6 haloalkoxy, C.sub.1 -C.sub.6 alkylthio, C.sub.1 -C.sub.6 alkylsulfinyl, C.sub.1 -C.sub.6 alkylsulfonyl, carboxy, carboxyamide (in which the groups attached to the N atom may be hydrogen or C.sub.1 -C.sub.10 hydrocarbyl optionally substituted with halogen), C.sub.1 -C.sub.6 alkoxycarbonyl or aryl;
• which process comprises the step of treating a hydroxythiazolidinone of formula II:
• ##STR14## in which A is as defined for formula I;
• with an oxidising agent.