include heteroaryl ring systems e g thienyl pyridyl pyrazole isoxazolyl thiadiazolyl oxadiazolyl indazolyl furans pyrroles imidazoles pyrazoles triazoles pyrimidines pyrazines thiazoles isoxazoles isothiazoles tetrazoles or oxadiazoles and heteroaryl ring systems in which a carbocyclic aromatic ring carbocyclic non aromatic ring heteroaryl ring or a heterocycloalkyl ring is fused to one or more other heteroaryl rings e g benzo b thienyl benzimidazole indole tetrahydroindole azaindole indazole quinoline imidazopyridine purine pyrrolo 2 3 d pyrimidine and pyrazolo 3 4 d pyrimidine an aralkyl group as used herein is an aromatic substituent that is linked to a moiety by an aliphatic group preferably having from one to about six carbon atoms a heterocycloalkyl group as used herein is a non aromatic ring system that preferably has 5 to 6 atoms and includes at least one heteroatom such as nitrogen oxygen or sulfur examples of heterocycloalkyl groups include morpholines piperidines and piperazines suitable substituents for aliphatic groups aromatic groups aralkyl groups heteroaromatic groups and heterocycloalkyl groups include aromatic groups halogenated aromatic groups lower alkyl groups halogenated lower alkyl e g trifluoromethyl and trichloromethyl u2014 o aliphatic group or substituted aliphatic group u2014 o aromatic group or substituted aromatic group benzyl substituted benzyl halogens cyano nitro u2014 s aliphatic or substituted aliphatic group and u2014 s aromatic or substituted aromatic as used herein a u201c protecting group u201d is a chemical group that is attached to a functional moiety for example to the oxygen in a hydroxyl group or the nitrogen in an amino group replacing the hydrogen to protect the functional group from reacting in an undesired way it is obviously desirable that a protecting group.