123229-11-8Relevant articles and documents
Syntheses and CD studies of new optically active substituted 1,5-benzodiazepine derivatives
Malik, Farnaz,Hasan, Mashooda,Khan, Khalid Mohammed,Perveen, Shahnaz,Snatzke, Guenther,Duddeck, Helmut,Voelter, Wolfgang
, p. 127 - 134 (2007/10/03)
Seventeen optically active substituted 1,3,4,5-tetrahydro-2H-1,5-benzodiazepine-2-thiones (1a to 1d, 2a to 2d, 3b to 3d, 4b to 4d and 5b to 5d) were synthesized by treating the corresponding optically active substituted 1,3,4,5-tetrahydro2H-1,5-benzodiazepin-2-ones with Lawesson's reagent (L. R.). The thioamide 1a was alkylated with methyl iodide to obtain 4-methyl-2-methylmercaptodihydro-1,5-benzodiazepine (6a) and 4,5-dimethyl-2-methylmercaptodihydro-1,5-benzodiazepine-2-thione (6b). Twelve optically active substituted 1,3,4,5-tetrahydro-2H-1,5-benzodiazepines (7a to 7c, 8a to 8d, 9a to 9d and 10d) were synthesized by the reduction of the corresponding substituted 1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-ones. 4-Methyl-1,5-diacetyl- (7e) and 1,4,5-trimethyl- (7d), 1,3,4,5-tetrahydro-2H-1,5-benzodiazepines were synthesized by treating 7 a with acetic anhydride and methyl iodide separately as given in the experimental part. The UV and CD spectra of the parent chiral benzodiazepines 7a to 7d and benzodiazepine-2-thiones 1a to 1d are discussed, showing that especially several n → π* transitions can be detected via the chiroptical methods only. Sign changes of Cotton effects upon N-5 methylation strongly suggest a conformational change of the 7-membered ring. VCH Verlagsgesellschaft mbH, 1996.
