[1
]Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral
Street, Glasgow, G1 1XL, U.K.
[2
]GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire
SG1 2NY, U.K.
[3
]GlaxoSmithKline, Medicines Research Centre, 709 Swedeland Road #1539, King of Prussia,
Pennsylvania 19406, United States
[4
]EaStCHEM, School of Chemistry, University of St. Andrews, North Haugh, St. Andrews
KY16 9ST, U.K.