Dicyclohexylcarbodiimide → Pent-4-ynoic acid 4-oxo-4H-benzo[d][1,2,3]triazin-3-yl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Pentynoic acid (200 mg, 2.04 mmol) was dissolved in THF (4 mL). The solution was cooled in a brine-icewater bath. A solution of dicyclohexylcarbodiimide (421 mg, 2.04 mmol) in THF (2 mL) was added. 3-Hydroxy-1,2,3-benzotriazin-4(3H)-one (333 mg, 2.04 mmol) was added after 5 minutes. The reaction mixture was stirred 1 h at −10° C. and then 2 h at room temperature. TLC indicated full conversion of 3-hydroxy-1,2,3-benzotriazin-4(3H)-one (eluent: ethyl acetate). Precipitated salts were filtered off. The filtrate was concentrated in vacuo and crystallized from hexane (4 mL). The crystals were filtered off and dried. Yield: 450 mg, 93%. RF=0.8 (ethyl acetate).

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