To prepare 3-(3,4-difluoro-benzoyl)-1,1-dimethyl-8-propylcarbamoyloxy)-1,2,3,6-tetrahydro-azepino[4,5-b]indole-5-carboxylic acid ethyl ester, a mixture of 3-(3,4-difluoro-benzoyl)-8-hydroxy-1,1-dimethyl-1,2,3,6-tetrahydro-azepino[4,5-b]-indole-5-carboxylic acid ethyl ester (45 mg, 0.1 mmol), triethylamine (0.1 mL), and propylisocyanate (0.2 mL) in dry DCM (5 mL) was refluxed at 60° C. for 20 hours. The solvent was removed in vacuo, and the residue was purified by preparative reverse-phase HPLC to give the title compound, which was then acylated in the manner described in Example 2A; 1H NMR (CDCl3): δ 10.62 (1H, s), 7.76-7.73 (2H, m), 7.52-7.47 (1H, m), 7.36-7.31 (1H, m), 7.24-7.19 (1H, m), 7.16 (1H, d), 6.86 (1H, m), 5.04 (1H, t), 4.26 (2H, q), 4.09 (2H, brs), 3.25 (2H, q), 1.66-1.54 (8H, m), 1.25 (3H, t), 0.99 (3H, t). MS (ES): 526 (MH+).
