RJCES Vol 6 [3] June 2018 103 | P age © 2018 AELS, INDIA ORIGINAL ARTICLE Ammonium Lauryl Sulfate: An Anionic Surfactant Catalyzed One Pot Green Synthesis of 1H-Benzo[d]imidazoles, Quinoxalines and 2,3-Dihydro-1H-benzo[b][1,4]diazepines at Room Temperature Deepali Agarwal*, Ankita Verma, Jyotsna Dhanik and Virendra Kumar Kasana Organic Synthesis Laboratory, Department of Chemistry, CBSH G.B. Pant University of Agriculture & Technology, Pantnagar (263145), U.S. Nagar, India *Corresponding author: Email: agarwal.deepali.15@gmail.com ABSTRACT We have developed a greener synthetic method for the synthesis of 1H-benzo[d]imidazoles, quinoxalines and 2,3- dihydro-1H-benzo[b][1,4]diazepines from the diversity of aromatic aldehydes, 1,2-diketones and ketones respectively at room temperature using anionic surfactant, ammonium lauryl sulfate (ALS) as an efficient catalyst and water as a solvent. This protocol gave 1H-benzo[d]imidazoles, quinoxalines and 2,3-dihydro-1H-benzo[b][1,4]diazepines in good to excellent yield with high purity. Keywords: 1H-benzo[d]imidazoles, quinoxalines, 2,3-dihydro-1H-benzo[b][1,4]diazepines, anionic surfactant, ammonium lauryl sulfate. Received 11.04.2018 Accepted 02.06.2018 © 2018 AELS, INDIA INTRODUCTION In synthetic organic chemistry, development of green methodologies in terms of solvent choice and catalyst design to reduce the waste generation is a key step in the reaction. Concept of green chemistry has open new vistas for synthetic chemists that encourage moving towards sustainable and innovative approach [1-8]. One of the important areas of green chemistry is to minimize energy consumption and replacement of toxic solvents with environmentally benign solvents. Water as a solvent has gained much attention as it is safe, inexpensive, non-toxic and environmentally friendly. Heterocycles represents significant compounds in drugs and pharmaceutically relevant substances [9]. Quinoxalines, benzodiazepines and benzimidazoles are the important class of nitrogen containing biologically active heterocyclic compounds. They are known to exhibit broad and diversified biological activities and thus, have achieved increasing interest in medicinal and pharmaceutical chemistry [10-21]. Therefore, their synthesis is desirable under the conventions of green chemistry [22]. Herein, we report a convenient and green approach for the synthesis of 1H-benzo[d]imidazoles, quinoxalines and 2,3-dihydro-1H- benzo[b][1,4]diazepines using ammonium lauryl sulfate as an efficient catalyst and water as a solvent. MATERIALS AND METHODS All chemicals and reagents were purchased from Hi-media and Sigma-Aldrich, and used without further purification. BRUKER AVANCE DRX-400 MHz spectrophotometer was used to record 1 H NMR spectra of synthesized compounds at ambient temperature using TMS as an internal standard. General Procedure for the Synthesis of 1H-Benzo[d]imidazoles To the 100 mL round bottom flask, 2 mmol aromatic aldehyde, 2 mmol benzene-1,2-diamine and 2 mol % of 30 % ALS in 2 mL distilled water were taken and stirred on magnetic stirrer at room temperature (Scheme 1). Reaction progress was monitored by silica gel TLC plates using hexane and ethyl acetate (70:30) solvent system. After completion of the reaction, crude solid product formed was washed with distilled water and dried. Recrystallization was done using ethanol. Research Journal of Chemical and Environmental Sciences Res J. Chem. Environ. Sci. Vol 6 [3] June 2018: 103-108 Online ISSN 2321-1040 CODEN: RJCEA2 [USA] ©Academy for Environment and Life Sciences, INDIA Website: www.aelsindia.com/rjces.htm R R R J J J C C C E E E S S S