摘要 |
Compounds are disclosed as useful as drugs or as intermediates for the manufacture of drugs, the compounds having the formula: <IMAGE> (I) in which X is hydrogen, chlorine, alkyl, alkoxy or alkylthio having 1 to 3 carbon atoms, R2 is hydrogen or alkyl having 1 to 3 carbon atoms, Y2 is chlorine and Y1 is chlorine or <IMAGE> in which R1 is hydrogen, straight or branched chain alkyl having 1 to 7 carbon atoms, cycloalkyl having 3 to 7 carbon atoms or cycloalkylalkyl having 4 to 8 carbon atoms, or Y2 and Y1 are both OH. Also disclosed are methods for preparation of the compounds. |