### Abstract

The kinetics of methyl transfer from 1-methyl-2,5-diphenyl-1,4-dithiinium tetrafluoroborate (1) to a series of thioanisoles (2) and to a comparable series of anilines (5) have been followed spectrophotometrically in acetonitrile under pseudo-first-order conditions at four temperatures for each compound. Derived second-order rate constants, Arrhenius equation constants, and activation thermodynamic parameters have been calculated for intra- and inter-series comparison. Both series exhibited well-defined Hammett correlations (ρS = -1.58 ± 0.04; corr coeff = 0.999 for the thioanisoles, and ρN = -1.95 ± 0.05; corr coeff = 0.998 for the anilines) in which the ρ values were essentially constant over the range 25-80 °C. Specific rate constants for the thioanisole set (k
_{S}
^{X}
) correlated well with those of the aniline set (k
_{N}
^{X}
) via a linear equation: log k
_{S}
^{X}
= m log k
_{N}
^{X}
+ constant, where the slope m is approximated by the ratio of Hammett ρ values (ρS/ρN)· Comparisons with literature data show that dimethyl sulfate is 2.3 times as reactive as 1 toward the thioanisoles, and that 1 is about 10 times as reactive as Mel toward the anilines.

Original language | English (US) |
---|---|

Pages (from-to) | 2753-2759 |

Number of pages | 7 |

Journal | Journal of Organic Chemistry |

Volume | 41 |

Issue number | 16 |

DOIs | |

State | Published - Aug 1 1976 |

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### Cite this

**Methylation of Thioanisoles and Anilines by 1-Methyl-2,5-diphenyl-1,4-dithiinium Tetrafluoroborate. Kinetics and Correlations.** / Young, Thomas E.; Oyler, Alan R.

Research output: Contribution to journal › Article

*Journal of Organic Chemistry*, vol. 41, no. 16, pp. 2753-2759. https://doi.org/10.1021/jo00878a024

}

TY - JOUR

T1 - Methylation of Thioanisoles and Anilines by 1-Methyl-2,5-diphenyl-1,4-dithiinium Tetrafluoroborate. Kinetics and Correlations

AU - Young, Thomas E.

AU - Oyler, Alan R.

PY - 1976/8/1

Y1 - 1976/8/1

N2 - The kinetics of methyl transfer from 1-methyl-2,5-diphenyl-1,4-dithiinium tetrafluoroborate (1) to a series of thioanisoles (2) and to a comparable series of anilines (5) have been followed spectrophotometrically in acetonitrile under pseudo-first-order conditions at four temperatures for each compound. Derived second-order rate constants, Arrhenius equation constants, and activation thermodynamic parameters have been calculated for intra- and inter-series comparison. Both series exhibited well-defined Hammett correlations (ρS = -1.58 ± 0.04; corr coeff = 0.999 for the thioanisoles, and ρN = -1.95 ± 0.05; corr coeff = 0.998 for the anilines) in which the ρ values were essentially constant over the range 25-80 °C. Specific rate constants for the thioanisole set (k S X ) correlated well with those of the aniline set (k N X ) via a linear equation: log k S X = m log k N X + constant, where the slope m is approximated by the ratio of Hammett ρ values (ρS/ρN)· Comparisons with literature data show that dimethyl sulfate is 2.3 times as reactive as 1 toward the thioanisoles, and that 1 is about 10 times as reactive as Mel toward the anilines.

AB - The kinetics of methyl transfer from 1-methyl-2,5-diphenyl-1,4-dithiinium tetrafluoroborate (1) to a series of thioanisoles (2) and to a comparable series of anilines (5) have been followed spectrophotometrically in acetonitrile under pseudo-first-order conditions at four temperatures for each compound. Derived second-order rate constants, Arrhenius equation constants, and activation thermodynamic parameters have been calculated for intra- and inter-series comparison. Both series exhibited well-defined Hammett correlations (ρS = -1.58 ± 0.04; corr coeff = 0.999 for the thioanisoles, and ρN = -1.95 ± 0.05; corr coeff = 0.998 for the anilines) in which the ρ values were essentially constant over the range 25-80 °C. Specific rate constants for the thioanisole set (k S X ) correlated well with those of the aniline set (k N X ) via a linear equation: log k S X = m log k N X + constant, where the slope m is approximated by the ratio of Hammett ρ values (ρS/ρN)· Comparisons with literature data show that dimethyl sulfate is 2.3 times as reactive as 1 toward the thioanisoles, and that 1 is about 10 times as reactive as Mel toward the anilines.

UR - http://www.scopus.com/inward/record.url?scp=33847799243&partnerID=8YFLogxK

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U2 - 10.1021/jo00878a024

DO - 10.1021/jo00878a024

M3 - Article

VL - 41

SP - 2753

EP - 2759

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 16

ER -