(E)-Trifluoromethyl-1-nitroethylene

Abstract

[37468-00-1] C3H2F3NO2 (MW 141.05) InChI = 1S/C3H2F3NO2/c4-3(5,6)1-2-7(8)9/h1-2H/b2-1+ InChIKey = FCKHHHXXJZMXBH-OWOJBTEDSA-N (reagent used as a three-carbon electrophile or dipolarophile) Physical Data: bp 80–85 °C; d 1.423 g cm−3. Solubility: alcohol, THF, chloroform and most organic solvents. Form supplied in: green-yellow liquid. It can contain 2–5% of the (Z)-isomer. Analysis of Reagent Purity: 1H, 13C and 19F NMR. 1H NMR (CDCl3): δ 7.10 (dq, 1H, CHCF3, JH–H = 13.1 Hz, JH–F = 6.4 Hz), 7.46 (dq, 1H, CHNO2, JH–H = 13.1 Hz, JH–F = 1.7 Hz); 19F NMR (CDCl3): δ −64.88 (dd, 3F, CF3, JH–F = 6.4 Hz, JH–F = 1.7 Hz); 13C NMR (CDCl3): δ 121 (q, CF3, J = 269 Hz), 126 (q, CHCF3, J = 37.5 Hz), 145 (s, CHNO2). Preparative Methods: Three main preparative methods have been described in the literature. Dehydration of 1,1,1-trifluoro-3-nitropropan-2-ol over P2O5 at ca. 140 °C.1 Deacetylation of 1,1,1-trifluoro-3-nitropropan-2-yl acetate over anhydrous potassium carbonate at 140 °C at reduced pressure (ca. 4 kPa).2 Dehydration of 1,1,1-trifluoro-3-nitropropan-2-ol over phthalic anhydride at 140–180 °C at reduced pressure.3 Fluorination of (E)-3-nitroacrylic acid by SF4 has been also reported as a method to obtain the title compound.4 Purification: fractional distillation at 760 mmHg. Handling, Storage, and Precautions: little is known about these issues. However, it has been reported1 that (E)-trifluoromethyl-1-nitroethylene is highly toxic. Since it is also quite volatile, it is recommended to cool down bottles in which it is stored, since pressure may develop. It is poorly stable in the presence of alkali and strong bases, and in general under basic conditions even at low temperature.