Synthesis of N-acylated 1,5-benzodiazepines: Differentiation between two possible acylation sites via hydrogen bonding

Carlos A. Escobar, Odette A. Alvarado, Judith A.K. Howard, MAURICIO DANIEL FUENTEALBA CARRASCO

Research output: Contribution to journalArticlepeer-review

Abstract

Temperature-dependent regioselectivity between amino and hydroxyl groups mediated by hydrogen bonding was observed in the reaction of acetic anhydride with 2-(2,3-dimethoxyphenyl)-4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiaz epine (1), obtaining 1-acetyl-2-(2,3-dimethoxyphenyl)-4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5- benzodiazepine (1a), when these were reacted at room temperature, and 4-(2-acetoxyphenyl)-1-acetyl-2-(2,3-dimethoxyphenyl)-2,3-dihydro-1H-1,5- benzodiazepine (1b), when they were refluxed (148-150 °C). Acylation of the less hindered analog 4-(2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine (2) via crotonyl chloride (a bulky acylating agent compared with acetic anhydride) afforded by refluxing only 1-crotonyl-4-(2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepin e (2a). All compounds were characterized spectroscopically, and the molecular structures of compounds 1a and 2a were determined by X-ray diffraction analysis.

Original languageEnglish
Pages (from-to)397-402
Number of pages6
JournalZeitschrift fur Naturforschung - Section C Journal of Biosciences
Volume68
Issue number4
StatePublished - 14 May 2013

Keywords

  • 1,5-benzodiazepine
  • Intramolecular hydrogen bond
  • N-acylation
  • Regioselectivity

Fingerprint Dive into the research topics of 'Synthesis of N-acylated 1,5-benzodiazepines: Differentiation between two possible acylation sites via hydrogen bonding'. Together they form a unique fingerprint.

Cite this