Gas‐phase pyrolytic reaction of 3‐phenoxy and 3‐phenylsulfanyl‐1‐propanol derivatives: Kinetic and mechanistic study

Abstract

3-Phenoxy-1-propanols 1a-c and 3-phenylsulfanyl-1-propanols 2a-c containing primary, secondary, and tertiary alcohols were prepared and subjected to gas-phase pyrolysis in a static reaction system. Pyrolysis of 4-phenyl-1-butanol 3, 2-methyl-3-phenyl-1-propanol 4, and 2-methyl-3-phenylpropanoic acid 5 was also studied, and results were compared with those obtained for compounds 1-3. The pyrolytic reactions were homogeneous and followed a first-order rate equation. Analysis of the pyrolysate showed the products to be phenol (from 1a to 1c), thiophenol (from 2a to 2c), and toluene (from 3 to 5) and carbonyl compounds. The kinetic results and product analysis of each of the nine investigated compounds are rationalized in terms of a plausible transition state for the elimination pathway. C 2007 Wiley Periodicals, Inc. Int J Chem Kinet 40: [51][52][53][54][55][56][57][58] 2008

Mahmoud, A. M.1; E. A. Ali1; Manal A. M. Hassan2* and Asmaa S. A. Sayed1 1 Department of Agronomy, Faculty of Agriculture, Assiut University, Assiut, 71526, Egypt 2 Food Science and Technology Department, Faculty of Agriculture, Assiut University, Assiut 71526, Egypt

“…Quinolines and isoquinolines have been extensively investigated because they are relevant to physics [7], chemistry [8], and medicine [9]. The thermal decomposition of these materials is essential to understand their behavior and stability in different environments [14][15][16][17][18][19][20][21][22][23]. Similar to esters [24][25][26][27], it was reported that thermolysis of alkoxy benzene and heteroaromatics produces olefins and the corresponding keto or enol form with activation energies depend on the structure of the reactants [14][15][16][17][18][19][20][21][22][23].…”

“…The thermal decomposition of these materials is essential to understand their behavior and stability in different environments [14][15][16][17][18][19][20][21][22][23]. Similar to esters [24][25][26][27], it was reported that thermolysis of alkoxy benzene and heteroaromatics produces olefins and the corresponding keto or enol form with activation energies depend on the structure of the reactants [14][15][16][17][18][19][20][21][22][23]. These gas phase degradation reactions are unimolecular, homogeneous, and pass over six-membered ring transition states [14][15][16][17][18][19][20][21][22][23].…”

Base‐Mediated O‐Arylation of Alcohols and Phenols by Triarylsulfonium Triflates

“…4‐Phenoxybutan‐2‐ol ( 3 aa ) . Light yellow oil (58.4 mg from a 0.4 mmol scale of 1 aa (36.2 mg), 88 %), a mixture of petroleum ether/ ethyl acetate=80/ 1 (v/ v) as eluents for column chromatography.…”

Gas-Phase Pyrolytic Reaction of 4-Aryl-3-buten-2-ols and Allyl Benzyl Ethers: Kinetic and Mechanistic Study

“…On the other hand, the analogous β-substituted propionic acids undergo retro-Michael elimination to give GH and acrylic acid, as shown in Equation 2 [ 2 ]. Moreover, various 3-anilino-1-propanol derivatives have been shown to undergo gas-phase pyrolysis via retro-ene reactions to give anilines, ethylene and carbonyl compounds, as shown in Equation 3 [ 3 , 4 ].…”

“…Pyrolysis of 1a-e is expected to proceed via 1,2-elimination similar to those shown in Equation 2 to produce 1-aryl-1,3-butadienes. On the other hand, pyrolysis of 5a-f is expected to proceed via a retro-ene mechanism similar to that shown in Equation 3 and which has widely been used in many useful synthetic applications [ 3 , 4 ].…”