75-47-8Relevant articles and documents
-
Suillot,Raynaud
, p. 4 (1889)
-
-
Fuson,Tullock
, p. 1638 (1934)
-
-
Teeple
, p. 170 (1904)
-
Base-Catalyzed Halogenation of Acetone
Tapuhi, Eliana,Jencks, William P.
, p. 5758 - 5765 (1982)
The kinetics of iodination and bromination of acetone were measured in basic aqueous solutions, buffered with trifluoroethanol, under conditions in which halogenation of the enolate ion is the rate-determining step.With the assumption of diffusion-controlled halogenation of the enolate ion by I2 and HOBr with k = 5 * 109 M-1 s-1, rate constants for other halogenating agents (M-1 s-1) are BrO-, 8 * 107; IO-, 108; IOH, 2.5 * 108; and I3-, 3.6 * 108; the pKa of acetone is 18.9 +/- 0.3 at 25 deg C, ionic strength 1.0 M (KCl) or 1.0 M (KNO3).Iodoform was identified spectrofotometrically as the product of iodination.Values of pKaSH = 10.8 and 10.6 for the enol give pKE = 8.1 and 8.3, respectively, for formation of the enol from acetone.It is suggested that the reactions of IO- and BrO- may proceed through the formation of a complex with the enolate, followed by protonation and halogenation, and that I3- may serve as an iodine donor through a preassociation mechanism.The observed dependence of the absorbance of I3- on buffer concentration and pH indicates the formation of a significant amount of a species with the composition ROIOH- at high concentrations of trifluoroethoxide and hydroxide ions.
The synergistic effect of copper chromite spinel nanoparticles (CuCr2O4) and basic ionic liquid on the synthesis of cyclopropanecarboxylic acids
Ghasemi, Mohammad Hadi,Kowsari, Elaheh
, p. 7963 - 7975 (2016/11/25)
Abstract: An efficient synthesis of cyclopropanecarboxylic acids using copper chromite spinel nanoparticles and basic ionic liquid is described. In this study, a relatively simple method starting with trans-cinnamic acid for the synthesis of (±)-trans-2-phenylcyclopropanecarboxylic acid, a key intermediate in the synthesis of tranylcypromine sulfate as an active pharmaceutical ingredient, was employed. Using a combination of basic ionic liquid [Bmim]OH and copper chromite spinel nanoparticles as a catalytic system, the best results were obtained in THF as a polar solvent. This method is a useful alternative to other approaches described in the literature. The use of commercially available chemicals, decreased environmental hazards, with no need for the separation of stereoisomers, and consequently a reduced number of overall steps, are the advantages of this approach that make it an appropriate choice at an increased scale. Graphical Abstract: [Figure not available: see fulltext.]
Photoproduct Characterization and Dynamics in the 248 nm Photlysis of CH3I Thin Films on Ag(111)
Coon, S. R.,Myli, K. B.,Grassian, V. H.
, p. 16416 - 16424 (2007/10/02)
The 248 nm photochemistry of methyl iodide thin films was studied using reflection absorption infrared spectroscopy (RAIRS), temperature programmed desorption (TPD), and time-of-flight quadrupole mass spectrometry (TOF-QMS).The formation of predominantly CH2I2 and CH4 and some C2H6, CH3CH2I, CHI3 and I2 photoproducts retained in the film was characterized by RAIRS and TPD.The integrated areas of the IR absorption bands for the two major photoproducts, CH2I2 and CH4, increase to a maximum and then decrease as photolysis of the film proceeds.A cross section for the loss of CH3I by 248 nm photolysis of the film was measured to be (1.0+/-0.1)E-19 cm2, approximately 1 order of magnitude lower than the gas-phase cross section.At all laser fluences used in this study, CH3, I, and CH3I were ejected into the gas phase.The CH3 TOF distribution showed the signature of the gas-phase CH3I photodissociation dynamics-two sharp peaks corresponding to the production of iodine atoms in the I(2P3/2) and I*(2P1/2) states.The TOF distributions of I and CH3I were fit by Maxwell-Boltzmann distributions corresponding to temperatures of 1400 and 1170 K, respectively.Three other species-CH4, I2 and CH2I2-were observed in TOF-QMS, but only at higher laser fluences.It was determined that the I2 and CH2I2 species are most likely fragments of a larger molecule, perhaps a cluster species, that photodesorbs as the film becomes enriched with photoproducts.The mechanism for CH4 photoejection appears to be of a different nature.The photochemistry of methyl iodide thin films can be understood in terms of a combination of photoproceses occuring in the film and at the film surface.
