Patent ID: 7135500

Claim:
A compound of formula 1 wherein: n is 1, 2, or 3; R 1 is —C 1 –C 4 -alkyl; R 3 denotes hydrogen; and R 2 , and R 4 , which are identical or different, are each —C 1 –C 4 -alkyl, —OH, —O—C 1 –C 4 -alkyl, —C 1 –C 4 -alkylene-halogen, —C 1 –C 4 -alkylene-OH, —C 1 –C 4 -alkylene-O—C 1 –C 4 -alkyl, —CF 3 , —CHF 2 , —NH 2 , —NH(C 1 –C 4 -alkyl), —N(C 1 –C 4 -alkyl) 2 , halogen, —COOH, —COO—C 1 –C 4 -alkyl, —NHCO—C 1 –C 4 -alkyl, —NHSO 2 —C 1 –C 4 -alkyl, or —SO 2 NH 2 , or an acid addition salt thereof.