To a solution of (S)-2-(7-bromo-2-cyclopropyl-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyethyl pivalate (18) (23 mg, 0.047 mmol) in DMA (2 ml), was added 2,3-dihydropyrano[4,3,2-de]quinolin-7-ylboronic acid (25 mg, 0.099 mmol), 2N K2CO3 solution (0.11 ml, 0.22 mmol) and Pd(PPh3)4 (6 mg, 0.005 mmol). The reaction mixture was reacted at 85° C. for 2 hs. The reaction was cooled down, washed by saturated NaHCO3 solution, extracted by EtOAc. The organic phase was combined, dry over MgSO4, filtered, concentrated and purified by silica gel column, eluting by 0-50% EtOAc in hexanes. Two isomers were separated and went through the chemistry sequence as above. LCMS-ESI+: calc'd for C33H38N2O4S: 559.2 (M+H+). Found: 559.1 (M+H+).
