Hydrochloric Acid → HCID 131729828, compound

Participants

Reaction Steps

Prepared from 5-(5-Trifluoromethyl-4-methyl-isoxazol-3-yl)-thiophene-2-carboxylic acid and tert-butyl methyl[(3R)-piperidin-3-ylmethyl]carbamate (Preparative Example 33, 298 mg, 1.30 mmol) by the method described in Example 2 Method B reversing the order of addition such that solid acid chloride (0.90 eq) was added to a THF solution of triethylamine and tert-butyl methyl[(3R)-piperidin-3-ylmethyl]carbamate. The reaction was allowed to stir 4 hr then partitioned between EtOAc (10 mL) and a 1 N aqueous HCl solution (10 mL). The organic portion was washed with a further portion of 1N HCl solution (10 mL) followed by a saturated aqueous NaHCO3 solution (10 mL) and brine (10 mL). The organic layer was then dried over MgSO4, filtered, and evaporated to a residue that was chromatographed on silica gel with EtOAc/hexane (40% then 60%) as eluant to afford Boc-protected intermediate as a yellow-tinted oil (423 mg, 67%). LC/MS 7.44 min, [M+1]+ 487. The intermediate was then treated with a 4 N solution of hydrogen chloride in 1,4-dioxane (4 mL) and stirred for 24 hr, after which time the reaction mixture was evaporated in vacuo to afford a free-flowing colorless powder (320 mg, 88%). LC/MS 4.91 min, [M+1]+ 388.

Provenance & Evidence