Potassium Hydroxide → 1,1-Dimethylethyl 4-[6-[(ethylamino)carbonyl]-2-fluoro-3-pyridinyl]-1-piperazinecarboxylate

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Reaction Steps

(2-Methyl-thiazol-4-yl)-methanol I-3t (155 mg, 1.2 mmol) was dissolved in dry toluene (5 mL) under dry nitrogen and 6′-chloro-2,3,5,6-tetrahydro-[1,2′]-bipyrazinyl-4-carboxylic acid tert-butyl ester (I-1a) (299 mg, 1.00 mmol), powdered KOH (191 mg, 3.4 mmol), and 18-crown-6 (13.2 mg, 50 μmol) were added with stirring. The mixture was heated at reflux with vigorous stirring. The mixture was stirred at reflux for 3 h then cooled to room temperature. The toluene was removed in vacuo. The residue was purified by preparative thin layer chromatography (10% methanol/90% CH2Cl2) to give the title compound I-3u as a viscous amber oil (375 mg, 96% yield).

Provenance & Evidence