SYNTHESIS, CHARACTERISATION AND ANTIMICROBIAL SCREENING OF 2,5-DIMETHYL-4-METHOXY (4-NITRO PHENOXY) BENZENE AND PHENOXY DERIVATIVES

Abstract

The increase of bacterial resistance to the main antibiotics used in therapy emphasize the need to develop new and more effective drugs with antimicrobial activities. This research is aimed at the synthesis, characterisation and antimicrobial screening of2,5-dimethyl-4-methoxy (4-nitro phenoxy) benzene and phenoxy derivatives which could serve as a potential antifungal and anti-bacterial agents. The reaction started with p-xylenol which was o-methylated in the presence of a base (12% NaOH) to give 2,5 dimethyl anisole, the product obtained was chlorosulphonylatedwith chlorosulphonic acid to give 2,5 dimethyl-4-methoxy benzene sulphonyl chloride.2,5 dimethyl-4-methoxy benzene sulphonyl chloride was reacted with proline room temperature in the presence of NaOH (5g) to give 2,5-dimethyl-4-sulphunyl proline anisole. The resulting product underwent conversion to acid chloride with thionyl chloride and cyclisation, respectively in the presence of triethy amine (TEA) at elevated temperature of 60-700C. Also,2,5 dimethyl-4-methoxy benzene sulphonyl chloride was coupled with phenols (4-bromo phenol, 4-nitro phenol, p-cresol) in presence of a base (NaOH) to give the phenoxy derivatives. Thisresearch led to the synthesis of three phenoxy derivatives (2,5-dimethyl-4-sulphonyl-(4-nitro phenoxy) anisole, 2,5-dimethyl-4-sulphonyl-(4-bromo phenoxy) anisole, 2,5-dimethyl-4-sulphonyl-(p-cresol) anisole) and other two synthesized compounds which were 2,5-dimethyl-4-sulphunyl proline anisole, 2,5-Dimethyl-4-methoxy [5,6-b] benzo (2,3-a) pyrolo-4-keto thiazine-1,1-dioxide,with antimicrobial activities. The plausible structure was elucidated using FT-IR and 1H NMR. The synthesized compoundswere tested against six bacteria (gram +ve and gram –ve) using agar dilution method and amoksiklov as standard namelyStaphylococcus aureus,Staphylococcus aureusenterobacteraerogenes, pseudomonousglycinear, erwiniacarotouora, clavibactermichinganensis, salmonella typii. Also the compoundswere screened for their antifungal activity against three pathogenic fungi, Collectotrichuinlindimuthianum, PhytophthorapalmivoraandFusariumvasinfectiumusing poisoned food technique and Mamcozebas a standard drug. The results for antibacterial activity showed that compound A (2,5-dimethyl-4-sulphonyl proline anisole) and D (2,5-Dimethyl-4-methoxy [5,6-b] benzo (2,3-a) pyrolo-4-keto thiazine-1,1-dioxide) were potential antibacterial agents.The result of antifungal activity revealed compound B (2,5-dimethyl-4-sulphonyl-(4-nitro phenoxy) anisole) and E (2,5-dimethyl-4-sulphonyl-(p-cresol) anisole) were potential antifungal agents against pathogenic fungi.