p-Toluenesulfonic acid → 2-((3aR,7aR)-2,2-dimethylhexahydrobenzo[d]oxazol-3(2H)-yl)benzo[d]thiazole-6-carbonitrile

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Reaction Steps

To a stirred mixture of 2-(((1R,2R)-2-hydroxycyclohexyl)amino)benzo[d]thiazole-6-carbonitrile (1.2 g, 4.5 mmol) from Step 2 of this Example and 2,2-dimethoxypropane (4.7 g, 45 mmol) in 1,4-dioxane (30 mL) were added para-toluenesulfonic acid (89 mg, 0.5 mmol) and molecular sieves (4 Å) and the mixture was heated at reflux for 15 h. The mixture was cooled to rt, filtered, and the filtrate was concentrated under reduced pressure. The residue was purified via silica gel flash chromatography to afford 2-((3aR,7aR)-2,2-dimethylhexahydrobenzo[d]oxazol-3(2H)-yl)benzo[d]thiazole-6-carbonitrile (700 mg, 50%) as a white solid. LCMS (ESI) m/z 314 (M+H)+.

Provenance & Evidence