ABSTRACT
Palladium-catalysed Suziki-Miyaura cross-coupling (SMC) reactions of 6-chloro-5H
benzo[a]phenothiazin-5-one, 11-amino-6-chloro-9-thio-5H-naphtho[2,1-b]pyrimido[5,4-e][1,4]
oxazin-5-one and 6-chloro-5H-naphtho[2,1-b]pyrido[2,3-e][1,4]oxazin-5-one with phenylboronic
acid and 3-nitophenylboronic acid were thoroughly investigated. The above intermediates were
prepared by the reactions of 2-aminothiophenol, 4,5-diamino-6-hydroxylpyrimidine-2-thiol and 2-
aminpyridin-3-ol respectively with 2,3-dichloronaphthalene-1,4-dione in a basic medium using
benzene/DMF as the solvent. Thereafter, each was subjected to the SMC reactions with
phenylboronic acid and 3-nitrophenyl boronic acid, refluxing for 7-8 h at 110 oC using
tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3), SPhos, potassium phosphate (K3PO4), and
toluene as the catalyst, ligand, base and solvent correspondingly to yield 6-phenyl-5Hbenzo[
a]phenothiazin-5-one and 6-(3-nitrophenyl)-5H-benzo[a]phenothiazin-5-one;11-amino-9-
mercapto-6-phenyl-5H-naphtho[2,1-b]pyrimido[5,4-e][1,4]oxazin-5-one and 11-amino-9-
mercapto-6-(3-nitrophenyl)-5H-naphtho[2,1-b]pyrimido[5,4-e][1,4]oxazin-5-one; and 6-phenyl-
5H-naphtho[2,1-b]pyrido[2,3-e][1,4]oxazin-5-one and 6-(3-nitrophenyl)-5H-naphtho[2,1-
b]pyrido[2,3-e][1,4]oxazin-5-one. Structures of the compounds were characterized using
UV/visible spectrophotometry, FT-IR, 1H-NMR and 13C-NMR spectroscopy and elemental
analysis. Using Ciprofloxacin (antibacterial) and Ketoconazole (antifungal) as reference drugs, the
compounds were screened against six (6) micro-organisms, viz: Bacillus subtitis, Staphylococcus
aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albican and Aspergillus niger; and were found to show significant activity against some gram-positive bacteria.
IKECHUKWU, A (2021). The Utility Of Suzuki-Miyaura Cross-Coupling Reaction In The Synthesis Of Angular Benzo[A]Phenothiazine And Benzo[A]Phenoxazine Derivatives And Their Anti-Microbial Screening. Afribary. Retrieved from https://afribary.com/works/the-utility-of-suzuki-miyaura-cross-coupling-reaction-in-the-synthesis-of-angular-benzo-a-phenothiazine-and-benzo-a-phenoxazine-derivatives-and-their-anti-microbial-screening
IKECHUKWU, AYOGU "The Utility Of Suzuki-Miyaura Cross-Coupling Reaction In The Synthesis Of Angular Benzo[A]Phenothiazine And Benzo[A]Phenoxazine Derivatives And Their Anti-Microbial Screening" Afribary. Afribary, 13 May. 2021, https://afribary.com/works/the-utility-of-suzuki-miyaura-cross-coupling-reaction-in-the-synthesis-of-angular-benzo-a-phenothiazine-and-benzo-a-phenoxazine-derivatives-and-their-anti-microbial-screening. Accessed 01 May. 2024.
IKECHUKWU, AYOGU . "The Utility Of Suzuki-Miyaura Cross-Coupling Reaction In The Synthesis Of Angular Benzo[A]Phenothiazine And Benzo[A]Phenoxazine Derivatives And Their Anti-Microbial Screening". Afribary, Afribary, 13 May. 2021. Web. 01 May. 2024. < https://afribary.com/works/the-utility-of-suzuki-miyaura-cross-coupling-reaction-in-the-synthesis-of-angular-benzo-a-phenothiazine-and-benzo-a-phenoxazine-derivatives-and-their-anti-microbial-screening >.
IKECHUKWU, AYOGU . "The Utility Of Suzuki-Miyaura Cross-Coupling Reaction In The Synthesis Of Angular Benzo[A]Phenothiazine And Benzo[A]Phenoxazine Derivatives And Their Anti-Microbial Screening" Afribary (2021). Accessed May 01, 2024. https://afribary.com/works/the-utility-of-suzuki-miyaura-cross-coupling-reaction-in-the-synthesis-of-angular-benzo-a-phenothiazine-and-benzo-a-phenoxazine-derivatives-and-their-anti-microbial-screening