Patent ID: 7220742

Claim:
A compound of formula 1 wherein the compound of formula 1 has an enantiomeric purity of at least 85% ee, and wherein R 1 is hydrogen, C 1 –C 4 -alkyl, C 1 –C 4 -alkoxy, or halogen; R 2 is hydrogen, C 1 –C 4 -alkyl, C 1 –C 4 -alkoxy, or halogen; R 3 is hydrogen, C 1 –C 4 -alkyl, C 1 –C 4 -alkoxy, halogen, OH, —O—C 1 –C 4 -alkylene-COOH, or —O—C 1 –C 4 -alkylene-COO—C 1 –C 4 -alkyl; R 4 is hydrogen, C 1 –C 4 -alkyl, C 1 –C 4 -alkoxy, or halogen; and X − is an anion with a single negative charge, optionally in the form of the tautomers, mixtures of the tautomers, hydrates, or solvates thereof.