5-(10-(tert-Butoxycarbonyl)-13-cyclohexyl-3-methoxy-7H-indolo[2,1-a][2]benzazepin-6-yl)-1,3-oxazole-4-carboxylic acid (185 mg, 0.334 mmol) was dissolved in DMF (3.2 ml), and O-benzotriazol-1-yl-N,N,N′,N′-tetra-methyluronium tetrafluoroborate (193 mg, 0.600 mmol) was added. The reaction was stirred capped at room temperature for 25 minutes and DMAP (163 mg, 1.334 mmol) was dissolved in the reaction then morpholine (0.058 ml, 0.667 mmol) was added. The reaction was capped and stirred at room temperature overnight. The reaction was poured into 30 ml of water and extracted with dichloromethane. The organic layer was washed sequentially with 0.1M aqueous citric acid, 0.1M aqueous NaH2PO4, then dried over anhydrous sodium sulfate. The sample was filtered, volatiles removed and the sample dried in vacuo to obtain 227 mg of an amorphous orange solid. 1H NMR (500 MHz, CHLOROFORM-D) δ ppm 1.16-1.50 (m, 7H) 1.53-1.61 (m, 6H) 1.62 (s, 10H) 1.76 (d, J=10.38 Hz, 2H) 1.83-2.15 (m, 5H) 3.40-3.84 (m, 7H) 3.83-3.95 (m, 5H) 4.40 (d, J=11.60 Hz, 1H) 5.64 (d, J=12.21 Hz, 1H) 6.97 (d, J=2.75 Hz, 1H) 7.05 (dd, J=8.39, 2.59 Hz, 1H) 7.50 (d, J=8.55 Hz, 1H) 7.53 (s, 1H) 7.65 (d, J=8.24 Hz, 1H) 7.77-7.86 (m, 2H) 7.97-8.04 (m, 1H) 8.10 (s, 1H). LC-MS retention time 2.64 min m/z 624 (MH+). LC data was recorded on a Shimadzu LC-10AS liquid chromatograph equipped with a Waters Xterra MS 7u C18 3.0×50 mm column using a SPD-10AV UV-Vis detector at a detector wave length of 220 nM. The elution conditions employed a flow rate of 5 ml/min, a gradient of 100% solvent A/0% solvent B to 0% solvent A/100% solvent B, a gradient time of 3 min, a hold time of 2 min, and an analysis time of 5 min where solvent A was 5% acetonitrile/95% H2O/10 mM ammonium acetate and solvent B was 5% H2O/95% acetonitrile/10 mM ammonium acetate. MS data was determined using a Micromass Platform for LC in electrospray mode.
