Patent ID: 7105673

Claim:
A compound of the formula III in which R 1 is hydrogen or alkyl; R 2 is CHO, —CH 2 OH, —CH 3 or CO 2 R 8 in which R 8 is hydrogen, alkyl, or aryl; or R 2 is —CH 2—0 -alkyl- in which alkyl is covalently bonded to the oxygen at the 3-position instead of R 1 ; R 3 is hydrogen and R 4 is hydroxy, halo, alkoxy or alkylcarbonyloxy; or R 3 and R 4 can be taken together to form ═O; R 5 and R 6 are hydrogen; or R 5 and R 6 are halo; and R 7 is hydrogen, alkyl, aryl, aralkyl, or CO 2 R 8 in which R 8 is hydrogen, alkyl, aryl, or aralkyl; or a pharmaceutically acceptable acid addition salt thereof.