Tetrahydrofuran → [4-(4-Nitrophenyl)but-3-ynyl]carbamic acid tert-butyl ester

Participants

Reaction Steps

To a mixture of anhydrous THF and triethylamine (20 mL, 1/1) were sequentially added 1-iodo-4-nitrobenzene (2.0 g, 8.032 mmol) and copper (I) iodide (0.31 g, 1.606 mmol). The mixture was stirred at room temperature for 15 min. The flask was evacuated and re-filled with argon four times to ensure no oxygen remained. The catalyst, dichlorobis(triphenylphosphine)-palladium(II) (0.56 g, 0.803 mmol) was added into the mixture under argon protection, followed by dropwise addition of but-3-ynyl-carbamic acid tert-butyl ester (1.62 g, 9.638 mmol). The newly formed reaction mixture was further stirred at room temperature overnight. The solid in the reaction mixture was vacuum filtered. The filtrate was concentrated. The residue was re-dissolved in methylene chloride and purified by column chromatography, eluting with a mixture of ethyl acetate (0-10%) and hexanes (100-90%) to afford 2.08 g (89%) of the product 51 as an orange solid. 1H NMR (CDCl3) δ 1.46 (s, 9H), 2.66 (t, J=6.5 Hz, 2H), 3.36-3.43 (m, 2H), 4.86 (br s, 1H), 7.53 (d, J=8.7 Hz, 2H), 8.16 (d, J=8.7 Hz, 2H). m/z (APCI)=291 [C15H18N2O4+H]+, 191 [C15H18N2O4-Boc+H]+.

Provenance & Evidence