Triethylamine → 4-{[4-(aminomethyl)piperidin-1-yl]methyl}tetrahydro-2H-pyran-4-carboxylic acid 4-methylbenzenesulfonate

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Reaction Conditions

Reaction Steps

In a 300 mL, 3-necked round bottom flask under N2, 4-[(4-{[(tert-butoxycarbonyl)amino]methyl}piperidin-1-yl)methyl]tetrahydro-2H-pyran-4-carboxylic acid (10 g, 28 mmol, step 4 of Example 8) was placed and a solution of p-toluenesulfonic acid monohydrate (16 g, 84 mmol) in i-propanol (150 mL) was poured at room temperature. The resulting mixture was stirred at 60° C. for 7 h under N2 and triethylamine (8.6 mL, 62 mmol) was added dropwise slowly during the period of 2 hr with seeding. The white precipitate was formed during the addition of triethylamine. The resulting white suspension was stirred at 60° C. for 3 h, at 50° C. for 5 h and at room temperature for 10 h. The suspension was filtered and the obtained solid was washed with i-propanol (100 mL), dried at 50° C. for 5 h to give 10.5 g (87%) of the titled compound as white powder.

Provenance & Evidence