A Facile and Efficient Synthesis of Arylsulfonamido‐Substituted 1,5‐Benzodiazepines and N‐[2‐(3‐Benzoylthioureido)aryl]‐3‐oxobutanamide Derivatives |
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Authors: | Abdolali Alizadeh Nasrin Zohreh |
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Institution: | 1. Department of Chemistry, Tarbiat Modares University, P.O. Box 14115‐175, Tehran, Iran, (phone: +98‐21‐88006631;2. fax: +98‐21‐88006544) |
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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, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 3). |
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Keywords: | Benzene‐1 2‐diamine Diketenes Enamines 1 5‐Benzodiazepine Sufonamides aryl‐ Multicomponent reactions Arylsufonyl isocyanate Benzoyl isothiocyanate |
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