Triethylamine (8 mL) was added to suspension of compound 14 (0.470 g, 2 mmol) in THF (40 mL) and the mixture was stirred at room temperature for 15 min. After this time 1-(3,5-diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide (0.15 g, 0.4 mmol) was added and the mixture was stirred at reflux for 3 h. The solution was then cooled to room temperature and the supernatant was isolated. The solvent was evaporated and the residual oil was washed with ether (2×50 mL), ethyl acetate (50 mL) and treated with 20 ml of 10% HCl. The obtained solid was isolated by filtration and dissolved in MeOH (approx. 50 mL). Addition of ethyl acetate (20 mL) to the solution caused the precipitation of a yellow solid, which was isolated by centrifugation, washed with ethyl acetate and dried under vacuum to give compound 15 (48 mg, 31%) as a yellow solid. 1H NMR (300 MHz, DMSO-d6) δ 1.80 (br s, 2H), 2.58 (m, 2H), 3.95 (br s, 4H), 6.70 (d, 2H), 7.03 (d, 2H), 7.48 (br. s, 2H), 8.80 (br s, 1H), 8.93 (br s, 1H), 9.32 (br s, 2H), 10.52 (s, 1H). APCI MS m/z 364 [C15H18ClN7O2+H]+.
