Methanol → 6-((2S,4R)-1-acetyl-4-((tert-butoxycarbonyl)amino)-2-methyl-1,2,3,4-tetrahydroquinolin-6-yl)nicotinic acid

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Reaction Conditions

Reaction Steps

To a stirring solution of crude methyl 6-((2S,4R)-1-acetyl-4-((tert-butoxycarbonyl)amino)-2-methyl-1,2,3,4-tetrahydroquinolin-6-yl)nicotinate (Intermediate 62) (2.2 g, 5.01 mmol) in MeOHl (12 mL), was added lithium hydroxide monohydrate (0.144 g, 6.01 mmol) in water (12 mL) and the mixture warmed to 50° C. for 70 mins. MeOH (10 mL) was added and the mixture stirred at 50° C. for a further 50 mins. The mixture was allowed to cool to room temperature before being partitioned between saturated aqueous sodium bicarbonate (150 mL) and DCM (3×150 mL). The aqueous layer was then treated with 2M HCl until acidic (˜pH 3) before being extracted with DCM (3×150 ml). The organics were combined, dried by passing through a hydrophobic frit and concentrated in vacuo to give 6-((2S,4R)-1-acetyl-4-((tert-butoxycarbonyl)amino)-2-methyl-1,2,3,4-tetrahydroquinolin-6-yl)nicotinic acid (2.08 g, 4.89 mmol). LCMS: (Formate, 2 min), Rt=0.86 mins, MH+426.

Provenance & Evidence