treatment of autoimmune diseases. The present invention relates to the use of a compound of formula I: wherein x is o, s, so or so2； R1 is halide, trialomethyl, -oh, C1-7 alkyl, C1-4 alkoxy, trifluoromethoxy, phenoxy, cyclohexylmethyloxy, pyridylmethoxy, cinnamyloxy, naphthylmethoxy, phenoxymethyl, -ch2-oh, -ch2-ch2-oh, C1-alkylthio -4-alkylsulfinyl, C 1-4 alkylsulfonyl, benzylthio, acetyl, nitro or cyano, or phenyl, phenylac 1-4 alkyl or phenyl-C 1-4 alkoxy, each phenyl group thereof being optionally substituted by halide, C 3-3, C 1-4 alkyl or C 1-4 alkoxy； R 2 is h, halide, rialomethyl, C 1-4 alkoxy, C 1-7 alkyl, phenethyl or benzyloxy； R 3 is halide, C 1-3, oh, C 1-7 alkyl, C 1-4 alkoxy, benzyloxy, phenyl or C 1-4 alkoxymethyl； each of r4 and r5 independently is h or a residue of formula (a) wherein each of r8 and r9 independently is h or C1-4alkyl optionally substituted by halide； and right an integer from 1 to 4； or a pharmaceutically acceptable salt, hydrate, solvate, isomer or prodrug thereof； or a compound of formula ii wherein R 1a is halide, trialomethyl, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkylthio, C 1-4 alkylsulfinyl, C 1-4 alkylsulfonyl, aralkyl, optionally substituted phenoxy or aralkyloxy； R 2a is h, halide, trialomethyl, C 1-4 alkyl, C 1-4 alkoxy, aralkyl or aralkyloxy； R 3a is h, halide, C 1-3, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkylthio or benzyloxy； R 4a is h, C 1-4 alkyl, phenyl, optionally substituted by benzyl or benzoyl, or C 1-5 lower aliphatic acyl； R 5a is h, monohalomethyl, C 1-4 alkyl, C 1-4 alkoxy methyl, C 1-4 alkylthiomethyl, hydroxyethyl, hydroxypropyl, phenyl, aralkyl, C 2-4 alkenyl or alkynyl； R 6a is h or C 1-4 alkyl； R7a is C1-4alkyl or a residue of formula (a) as defined above, xa is o, s, so or so2； and na is an integer from 1 to 4； or a pharmaceutically acceptable salt, hydrate, solvate, isometer or prodrug thereof； in the manufacture of a medicament for the treatment or prophylaxis of subacute cutaneous lupus erythematosus (scl
