Carbamoyloxy arylalkanoyl arylpiperazine analgesics

A compound of Formula 1:

• or a pharmaceutically acceptable salt or hydrate thereof, wherein - - - denotes an optional bond forming a cyclic moiety;
• each of R1 and R2 is independently selected from the group consisting of H- and straight- or branched-chain C1-C6 alkyl, or
• R1 and R2 are taken together to form piperidinyl or piperazinyl, or R1 and R2 are taken together with Ar1 to form benzo[d][1,3]oxazin-2-one moiety;
• Ar1 is selected from the group consisting of furanyl, methylenedioxyphenyl and phenyl which is optionally substituted by one or more substituents independently selected from the group consisting of H-, straight- or branched-chain C1-C6 alkyl, fluoro, chloro, bromo, straight- or branched-chain C1-C6 alkoxy, nitro and trifluoromethyl;
• z is H- or fluoro;
• Ar2 is selected from the group consisting of phenyl, methylenedioxyphenyl, pyridinyl, pyrimidinyl, naphthyl, and quinoxalinyl, wherein Ar2 is optionally substituted by one or more substituents independently selected from the group consisting of H-, straight- or branched-chain C1-C6 alkyl, hydroxy, halo, straight- or branched- chain C1-C6 alkoxy, nitro, acetyl, t-butylacetyl, trifluoromethyl, amino and acetyloxy;
• n is 1 or 2;
• and
• m is 0, 1 or 2.