title: A Palladium-Catalyzed Method for the Synthesis of 2-(α-Styryl)-2,3-dihydroquinazolin-4-ones and 3-(α-Styryl)-3,4-dihydro-1,2,4-benzothiadiazine-1,1-dioxide: Access to 2-(α-Styryl)quinazolin-4(3H)-ones and 3-(α-Styryl)-1,2,4-benzothiadiazine-1,1-dioxides.
abstract: An efficient synthesis of 2-(α-styryl)-2,3-dihydroquinazolin-4-ones and 3-(α-styryl)-3,4-dihydro-1,2,4-benzothiadiazine-1,1-dioxides has been achieved in 39-94% yield through palladium-catalyzed cyclocondensation of aryl/vinyl iodides with allenamides 13-15 and 22, respectively. Base treatment of the N-tosylated products provides an easy access to 2-(α-styryl)quinazolin-4(3H)-ones and 3-(α-styryl)-1,2,4-benzothiadiazine-1,1-dioxides, hitherto unknown heterocycles. The method has been tested with phenyl substituted allenamides, applied for bis-heteroannulation, and used in the preparation of analogues of the natural product Luotonin F.
authors.affiliation: Organic & Medicinal Chemisty Division, CSIR-Indian Institute of Chemical Biology , 4, Raja S.C. Mullick Road, Kolkata-700032, India.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Kundu
authors.affiliation: Organic & Medicinal Chemisty Division, CSIR-Indian Institute of Chemical Biology , 4, Raja S.C. Mullick Road, Kolkata-700032, India.
authors.forename: Amrita
authors.initials: A
authors.lastname: Mondal
authors.affiliation: Organic & Medicinal Chemisty Division, CSIR-Indian Institute of Chemical Biology , 4, Raja S.C. Mullick Road, Kolkata-700032, India.
authors.forename: Chinmay
authors.initials: C
authors.lastname: Chowdhury