Allyl 1H-Imidazole-1-carboxylate

Abstract

[83395-39-5 C7H8N2O2 (MW 152.15) InChI = 1S/C7H8N2O2/c1-2-5-11-7(10)9-4-3-8-6-9/h2-4,6H,1,5H2 InChIKey = NEFLGCHXJFBCQP-UHFFFAOYSA-N (acylating reagent for introduction of the carboxyallyl group to nucleophilic species such as amines, alcohols, and carbanions; used to convert carboxylic acids into allyl esters; used to synthesize substrates for transition metal-catalyzed allylic alkylation) Alternate Names: allyl imidazole carbamate, AllylImC, Heller-Sarpong Reagent, allyl 1H-imidazole-1-carboxylate, imidazole-1-carboxylic acid 2-propen-1-yl ester. Physical Data: colorless oil, d = 1.146 g mL−1 at 25 °C. Solubility: soluble in most common organic solvents (e.g., CH2Cl2, THF, ethyl acetate, acetonitrile); reacts with water, amines, and alcohols. Form Supplied in: colorless to yellow oil. Available from Sigma-Aldrich. Preparative Method: prepared by adding allyl alcohol to a slight excess of 1,1′-carbonyldiimidazole (CDI)1 or by adding allyl chloroformate to 2 equiv. of imidazole in THF.2 Analysis of Reagent Purity: typically analyzed by 1H-NMR: (400 MHz, CDCl3) δ 8.14 (s, 1H), 7.42 (t, J = 1.3 Hz, 1H), 7.05 (s, 1H), 6.00 (ddt, J = 16.4, 10.4, 6.0 Hz, 1H), 5.40 (m, 2H), 4.87 (dt, J = 6.0, 1.1 Hz, 2H).2 Purity may also be analyzed by HPLC. Purification: may be purified by flash chromatography on silica gel. Residual imidazole may be removed by washing a solution of allyl imidazole carbamate in CH2Cl2 or ethyl acetate with water. Handling, Storage, and Precautions: allyl imidazole carbamate is a reactive acyl electrophile and should be protected from moisture. The reagent can evolve CO2 (pressure!) upon prolonged contact with moisture during storage; therefore, bottles should be opened carefully. The reagent is presumed to be harmful if swallowed, inhaled, or absorbed through the skin. Use in a fume hood.