Synthesis 2009(13): 2163-2170  
DOI: 10.1055/s-0029-1216831
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

One-Pot Microwave-Assisted Selective Azido Reduction/Tandem Cyclization in Condensed and Solid Phase with Nickel Boride

Nagula Shankaraiaha, Nagula Markandeyab, Marlene Espinoza-Moragaa, Claudia Arancibiaa, Ahmed Kamal*b, Leonardo Silva Santos*a
a Laboratory of Asymmetric Synthesis, Chemistry Institute of Natural Resources, University of Talca, P.O. Box 747, Talca, Chile
e-Mail: lssantos@utalca.cl;
b Chemical Biology Laboratory, Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500007, India
Fax: +91(40)27193189; e-Mail: ahmedkamal@iict.res.in;
Further Information

Publication History

Received 26 January 2009
Publication Date:
19 May 2009 (online)

Abstract

An efficient and inexpensive method using microwave-assisted irradiation with Ni2B for the syntheses of aromatic amines, pyrrolobenzodiazepines as well as pyrroloquinazolinones was developed. This protocol was applied in the tandem resin-cleavage, azido reduction, and cyclization of compounds 3 and 5 that afforded substituted pyrrolo[2,1-c][1,4]benzodiazepines 4 and 6 in a one-pot manner. The microwave-assisted irradiation reactions enhanced yields with very short reaction times in contrast to the conventional thermal reactions.