Substituent effects on thermal rearrangement of 3-(substituted phenyl)-4-(p-tolyl)-1,2,4-oxadiazole-5(4H)-thiones


Agirbas H., Toker A.

JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, cilt.14, ss.58-61, 2001 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 14 Konu: 1
  • Basım Tarihi: 2001
  • Dergi Adı: JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
  • Sayfa Sayıları: ss.58-61

Özet

The kinetics of the rearrangement of 3-(substituted phenyl)-4-(p-tolyl) 1,2,4-oxadiazole-5(4H)-thiones in solution were determined in the temperature range 160-200 C-degrees. From the correlation of logk against sigma, it was found that for m-Me, p-Cl and p-CN, the compounds rearrange with the homolytic cleavage of the N-O bond, whereas for p-Me, H and m-NO2, the rearrangement occurs with the heterolytic cleavage of the N-O bond. In comparison with the uncatalysed rearrangement, Cu catalysis greatly increased the rate of the rearrangement of 3-(m-chlorophenyl)-4-(p-tolyl)-1,2,4-oxadiazole-5(4H)-thione at 166 degreesC. Copyright (C) 2000 John Wiley & Sons, Ltd.