title: Synthesis and antitubercular evaluation of amidoalkyl dibenzofuranols and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones.
abstract: A new class of amidoalkyl dibenzofuranols and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones was synthesized in very good yields through polyphosphoric acid supported on silica (PPA-SiO(2)) catalyzed one-pot three component condensation of 2-dibenzofuranol; aromatic aldehydes and acetamide or benzamide or urea under solvent free conditions. At 125°C the reaction led to the formation of amidoalkyl dibenzofuranols 5a-k where as at 160°C cyclization take place to give oxazin-3(2H)-one analogues 6a-e. Screening all the 16 compounds for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) resulted 1-((4-chlorophenyl)(2-hydroxydibenzo[b,d]furanyl)methyl)urea 5h; 1-((4-bromophenyl)(2-hydroxydibenzo[b,d]furanyl)methyl)urea 5i; 1-phenyl-1H-benzo[2,3]benzo furo[4,5-e][1,3]oxazin-3(2H)-one 6a (MIC 3.13μg/mL) and 1-(4-chlorophenyl)-1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-one 6b; 1-(4-bromophenyl)-1H-benzo[2,3]benzofuro [4,5-e][1,3]oxazin-3(2H)-one 6c (MIC 1.56μg/mL) as most active antitubercular agents.
authors.affiliation: Organic Chemistry Division-II, Indian Institute of Chemical Technology, Hyderabad 500 007, India.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Kantevari
authors.forename: Thirumal
authors.initials: T
authors.lastname: Yempala
authors.forename: Perumal
authors.initials: P
authors.lastname: Yogeeswari
authors.forename: Dharmarajan
authors.initials: D
authors.lastname: Sriram
authors.forename: Balasubramanian
authors.initials: B
authors.lastname: Sridhar
mesh_terms: D000995:Antitubercular Agents / Q000138:chemical synthesis* / Q000737:chemistry; D001572:Benzofurans / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D010078:Oxazines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D010756:Phosphoric Acids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature; D014508:Urea / Q000737:chemistry
chemical_list: D000995:Antitubercular Agents; D001572:Benzofurans; D010078:Oxazines; D010756:Phosphoric Acids; D011108:Polymers; D012822:Silicon Dioxide; C047269:polyphosphoric acid; C023614:dibenzofuran; D014508:Urea