Maximally inhibited gas phase elimination kinetics of methyl 3-bromopropionate

The gas phase elimination of methyl 3-bromopropionate has been studied in a static system and in vessels seasoned with allyl bromide. The reaction is autocatalyzed by HBr. However, under maximum inhibition with propene, the reaction obeys first order kinetics and is a homogeneous unimolecular elimination. The products are methyl acrylate and hydrogen bromide. The observed rate coefficients are represented by the Arrhenius equation: log k₁ (s^–1)=(12.94±0.46)–(214.5±6.0) kJ/mol/2.303 RT in the temperature range 400.1–449.9 °C and pressure range 49–98 Torr. The pyrolysis of methyl 3-bromopropionate is 3.5 times faster than that of ethyl bromide. This significant difference may be attributed to the greater acidity of the -hydrogen in 3-bromopropionate compared to that in ethyl bromide.

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3- , . HBr . . . , , : log k₁ (^–1)=(12,94±0,46)–(214,5±6,0) ·^–1/2,303 RT 400,1–449,9°C 49–98 . - 3,5 , . - - .