A mixture comprising of 3,4-diethoxycyclobut-3-ene-1,2-dione (29.0 μl, 0.196 mmol) and triethylamine (1093 μl, 7.84 mmol) in EtOH (654 μl) was stirred at 40° C. for 20 minutes. The reaction was allowed to cool back to room temperature and 3,5-dichlorobenzyl 2-(2-(methylamino)ethyl)morpholine-4-carboxylate (Example 13, step 2) (68.1 mg, 0.196 mmol) was added. The reaction mixture was allowed to stir at room temperature for 16 hours. The resulting reaction mixture was concentrated under reduced pressure and purification was carried our using preparative LC-MS. The resulting product fractions were concentrated under reduced pressure to give an aqueous solution and then extracted with EtOAc. The organic extracts were dried over MgSO4, filtered and concentrated under reduced pressure to afford the title compound;
