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A Facile and Efficient Synthesis of Arylsulfonamido‐Substituted 1,5‐Benzodiazepines and N ‐[2‐(3‐Benzoylthioureido)aryl]‐3‐oxobutanamide Derivatives
Author(s) -
Alizadeh Abdolali,
Zohreh Nasrin
Publication year - 2010
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200900364
Subject(s) - chemistry , diketene , aryl , medicinal chemistry , imine , benzene , ring (chemistry) , substituent , enamine , isothiocyanate , diazepine , diamine , isocyanate , stereochemistry , organic chemistry , catalysis , polyurethane , alkyl
Abstract A facile and efficient synthesis of 1,5‐benzodiazepines with an arylsulfonamido substituent at C(3) is described. 1,5‐Benzodiazepine, derived from the condensation of benzene‐1,2‐diamine and diketene, reacts with an arylsulfonyl isocyanate via an enamine intermediate to produce the title compounds of potential synthetic and pharmacological interest in good yields ( Scheme 1 ). In addition, reaction of benzene‐1,2‐diamine and diketene in the presence of benzoyl isothiocyanate leads to N ‐[2‐(3‐benzoylthioureido)aryl]‐3‐oxobutanamide derivatives ( Scheme 2 ). This reaction proceeds via an imine intermediate and ring opening of diazepine. The structures were corroborated spectroscopically (IR, 1 H‐ and 13 C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed ( Scheme 3 ).