Patent EP-0904268-A1 (EP)
Title: Processes for preparing 3-(1-hydroxyphenyl-1-alkoximinomethyl)dioxazines
Inventor: GAYER HERBERT
IPC: C07D273/01
Filed: 1997-05-16
Abstract: The single-step preparation of 3-(hydroxyphenyl-1-alkoximinomethyl)dioxazine derivatives of formula (I) from compounds (II), (III) and (V), and the preparation in 2-5 steps from (VII), (VIII), (X), (XI), (XII), (XIV) and (XVI) (via (II), (III) and (V)) are claimed. The preparation of the intermediates is also claimed. The single-step preparations comprise (a) isomerisation of the O-hydroxyethyl-O'-methyl-benzofuran dione dioxime (II) of formula (X'; Q = CZ3Z4CZ1Z2OH; Y = NOA); (b) treatment of the ketone of formula (III) with the alkoxyamine of formula A-O-NH2 (IV) or its acid addition complex, optionally in the presence of a diluent and/or acid acceptor; and (c) by reacting the hydroxylamine of formula (V) with an alkylating agent of formula AX (VI), optionally in the presence of a diluent and/or base. Preparation of (II) comprises (d) reaction of O-hydroxyethylbenzofuran dione monooxime (VII) of formula (X'; Q = CZ3Z4CZ1Z2OH; Y = O) with (IV); (e) reaction of O-alkylbenzofuran dione dioxime (VIII) of formula of formula (X'; Q = H; Y = NOH) with the alcohol of formula Y1CZ3Z4-CZ1Z2-OG (IX); (f) reaction of benzofuran dione mono-oxime (X) of formula (X'; Q = CZ3Z4CZ1Z2OH; Y = NOH) with (VI); or (m) reaction of O-oxyethyl-O'-methyl-benzofurandione dioxime compounds (XIII) of formula (X'; Q = CZ3Z4CZ1Z2OE; Y = NOH) with water or an alcohol, optionally in the presence of acid or base. (VII) is prepared by (g) reaction of (XI) with (IX); or (n) reaction of benzofuran dione mono-oxime (XIV) of formula (X'; Q = CZ3Z4CZ1Z2OE; Y = O). (XIV) is prepared by: (o) reaction of (XI) with ethanol derivatives of formula Y2CZ3Z4CZ1Z2OE (XV), optionally in the presence of an acid acceptor. (VIII) is prepared by: (h) reaction of (XI) with (IV); or (p) reaction of the benzofuran dione dioxime (XII) of formula (X'; Q = H; Y = NOH) with (VI), optionally in the presence of a base. (X) is prepared by: (i) reaction of (VII) with hydroxylamine; or (q) reaction of O-oxyethylbenzofuran dione dioxime (XVI) of formula (X'; Q = CZ3Z4CZ1Z2OE; Y = NOH) with water or an alcohol. (XVI) is prepared by: (r) reaction of (XIV) with hydroxylamine. (XIII) is prepared by: (s) reaction of (XIV) with (IV); (t) reaction of (XVI) with (VI); (u) reaction of (VIII) with (XV). (III) is prepared by: (k) isomerisation of (VII); (V) is prepared by (l) reaction of (III) with hydroxylamine; or (v) reaction of (X). Optionally: reactions are carried out in the presence of diluent, and hydrolyses in base or acid, reaction with alkoxylamine, hydroxylamine or XV) with an acid acceptor; reaction with (IX) or (IX), in base; and isomerisations with acid. A = alkyl; E = acyl or a ketal protection group; R1-R4 = H, halo, CN, nitro, or alkyl, alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl (all optionally substituted by halo); Z1-Z4 = H, alkyl, haloalkyl or hydroxyalkyl; or Z1+Z2, Z1+Z3, Z3+Z4 complete a cycloaliphatic ring; X, Y1, Y2 = halo, alkylsulphonyloxy, alkoxysulphonyloxy or arylsulphonyloxy; G = H; or Y1+G = bond or OCO.   (II), (VII), (XIV), (VIII), (X), (XVI), (XIII), (III) and (V) are new.