Microwave-mediated heterocyclization to benzimidazo[2,1-b]quinazolin-12(5H)-ones.
An effective route to benzimidazo[2,1-b]quinazolin-12(5H)-ones from commercially available o-aryl isothiocyanate esters and o-phenylenediamines is reported. This method accommodates a variety of substituents on either starting material and proceeds under microwave irradiation in the presence of barium hydroxide, conditions that do not hydrolyze methyl ester substituents. The pharmacologically pertinent benzimidazoquinazolinone heterocycle is delivered in excellent yield and purity via both solution- and solid-phase protocols, the latter involving traceless release from the resin.
Carpenter
Richard D
RD
Department of Chemistry, University of California, Davis, One Shields Ave., Davis, California 95616, USA.
Lam
Kit S
KS
Kurth
Mark J
MJ
D001562:Benzimidazoles / Q000737:chemistry*; D008872:Microwaves; D015394:Molecular Structure; D011799:Quinazolines / Q000138:chemical synthesis / Q000737:chemistry*; D012996:Solutions
D001562:Benzimidazoles; D011799:Quinazolines; D012996:Solutions