Patent ID: 8507552

Claim:
A compound of formula I: wherein: each R 1 is independently H, (C 1 -C 6 )alkyl, aryl(C 1 -C 6 )alkyl-, (C 3 -C 6 )cycloalkyl or aryl; and each R 2 is independently H, (C 1 -C 6 )alkyl, aryl(C 1 -C 6 )alkyl-, (C 3 -C 6 )cycloalkyl or aryl; or R 1 and R 2 together with the atom to which they are attached form a (C 3 -C 7 )cycloalkyl; wherein any alkyl or cycloalkyl of R 1 or R 2 may be optionally substituted with one or more groups selected from halo, (C 1 -C 6 )alkoxy and NR a R b and wherein any aryl of R 1 or R 2 may be optionally substituted with one or more groups selected from halo, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, NR a R b , nitro and cyano; R a and R b are each independently selected from H, (C 1 -C 6 )alkyl, (C 3 -C 6 )cycloalkyl and aryl; or R a and R b together with the nitrogen to which they are attached form a pyrrolidino, piperidino, piperazino, azetidino, morpholino, or thiomorpholino; n is 1, 2 or 3; and each X is H; or a salt thereof.