F:Flammable;
624-65-7Relevant articles and documents
Isomerization and decomposition of chloromethylacetylene
Kumaran, Soundararajan S.,Lim, Kee P.,Michael, Joe V.,Tilson, Jeffrey L.,Suslensky, Aya,Lifshitz, Assa
, p. 223 - 232 (1996)
The isomerization and thermal decomposition of chloromethylacetylene (CMA) has been studied with two shock tube techniques. The first experiment (Jerusalem) utilizes single-pulse shock tube methods to measure the isomerization rate of CMA to chloroallene. In addition, equilibrium constants can be estimated at ～1200 K. The second experiment (Argonne) monitors Cl-atom formation at temperatures above ～1150 K. Absolute yield measurements have been performed over the 1200-1700 K range and indicate that two decomposition channels contribute to CMA destruction, namely, Cl fission and HCl elimination. The results show that the branching fraction between processes is temperature dependent. Therefore, direct Cl-atom fission is accompanied by molecular elimination, undoubtedly giving HCl and one or more isomers of C3H2. MP2 6-31G(d,p) ab initio electronic structure calculations have been used to determine vibration frequencies and moments of inertia for three C3H3Cl isomers. Using these quantities, the experimental equilibrium constants required that ΔH00(CH2Cl-C≡CH ? CHCl=C=CH2) = -0.24 kcal mole-1. A potential energy surface pertinent to the present system has been constructed, and RRKM calculations have been carried out in order to explain the isomerization rates. The isomerization data can be explained with E0 = 52.3 kcal mole-1 and 〈ΔEdown〉 = 225 cm-1. Subsequent semi-empirical Troe and RRKM-Gorin modeling of the Cl atom rate data require E0 = (67.5 ± 0.5) kcal mole-1 with a (ΔEdown) = (365 ± 90) cm-1. This suggests a heat of formation for propargyl radicals of (79.0 ± 2 5) kcal mole-1.
A mild method for the replacement of a hydroxyl group by halogen: 3. the dichotomous behavior of α-haloenamines towards allylic and propargylic alcohols
Munyemana, Fran?ois,Patiny, Luc,Ghosez, Léon
, (2021/06/07)
A study of the deoxyhalogenation of allylic and propargylic alcohols with tetramethyl-α-halo-enamines is reported. Primary allylic and primary and secondary propargylic alcohols gave the corresponding halides in high yields. Secondary allylic and propargylic alcohols yielded the corresponding secondary halides but the reaction also produced some rearranged primary halides (I > Br > Cl). The reactions with tertiary allylic and tertiary propargylic alcohols gave several products and was therefore of little synthetic value. However, the addition of triethylamine to the reaction mixture or the use of lithium alkoxide instead of alcohol brought about a major change of the course of the reaction which led to amides carrying an allyl or an allenyl group at C2. This was shown to result from a Claisen-Eschenmoser rearrangement of an intermediate α-allyloxy- or propargyloxy-enamine.
METHOD OF CONVERTING ALCOHOL TO HALIDE
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Page/Page column 53; 113; 114, (2017/01/02)
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
