Patent ID: 6844359

Claim:
A substantially pure R or S isomer of a compound of formula (I): wherein, R 1 is phenyl which is substituted with one or more substituents each independently selected from the group consisting of nitro, cyano, trifluoromethyl, carbethoxy, carbomethoxy, carbopropoxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, alkyl of 1 to 10 carbon atoms, alkoxy of 1 to 10 carbon atoms, and halo; R 2 is alkyl of 1 to 10 carbon atoms, phenyl, pyridyl, heterocycle, —CH 2 —aryl, or —CH 2 -heterocycle; R 3 is (i) ethylene, (ii) vinylene, (iii) vicinal alkylene of 3 to 10 carbon atoms, (iv) vicinal alkenylene of 3 to 10 carbon atoms, (v) cycloalkylene of 4 to 9 carbon atoms, unsubstituted or substituted with 1 to 2 substituents each selected independently from the group consisting of nitro, cyano, trifluoromethyl, carbethoxy, carbomethoxy, carbopropoxy, acetyl, carbamoyl, acetoxy, carboxyl hydroxy, amino, substituted amino, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, and halo, (vi) cycloalkenylene of 4 to 9 carbon atoms unsubstituted or substituted with 1 to 2 substituents each selected independently from the group consisting of nitro, cyano, trifluoromethyl, carbethoxy, carbomethoxy, carbopropoxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, substituted amino alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, and halo, or (vii) o-phenylene unsubstituted or substituted with 1 to 2 substituents each selected independently from the group consisting of nitro, cyano, trifluoromethyl, carbethoxy, carbomethoxy, carbopropoxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, substituted amino alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms and halo; and R 4 is —CH 2 — or —CX in which X is O or S.