Potassium tert-butoxide → tert-butyl 2-(8-(benzo[d]thiazol-2-yl((2-(trimethylsilyl)ethoxy)methyl)carbamoyl)-3,4-dihydroisoquinolin-2(1H)-yl)thiazole-4-carboxylate

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Reaction Steps

To a stirring solution of methyl 2-(8-(benzo[d]thiazol-2-yl((2-(trimethylsilyl)ethoxy)methyl)carbamoyl)-3,4-dihydroisoquinolin-2(1H)-yl)thiazole-4-carboxylate (38A) (14 g, 24.1 mmol) in t-butyl acetate (200 mL) was added 2 mL of t-BuOK in THF (2M) under vacuum. 3×2 mL t-BuOK were added to the stirring solution under vacuum to drive the reaction to complete. The mixture was then acidified to neutrality and washed with water, brine, dried over Na2SO4, and concentrated under reduced pressure. The crude material was purified by column chromatography on silica gel eluting with 5% EtOAc in hexanes to provide 3.5 g of the desired product 38B: 1H NMR (300 MHz, CDCl3) δ ppm 8.29 (1H, m), 7.71 (1H, d), 7.62 (2H, m), 7.49 (2H, t), 7.34 (3H, m), 6.02 (2H, s), 5.20 (2H, s), 4.02 (2H, m), 3.71 (3H, m), 3.08 (2H, m), 1.59 (9H, t), 0.97 (2H, m), −0.09 (9H, m). MS (ESI(+)): m/z 623.0 (M+H).

Provenance & Evidence