The synthesis of oximes from their corresponding carbonyl-containing organic compounds using hydroxylamine hydrochloride and wet silica gel.

In this thesis, a series of different aldehydes and ketones were converted to their corresponding oximes using the NH2OH.HCl/Wet-SiO2 system. Experiments were conducted using SiO2/H2O (50/50 w/w%) at a temperature of 50-60 °C. The corresponding Z-aldoximes and E-ketoximes were obtained with excellent yields (85-95%) within a reaction time of 70-180 minutes. Oximes are used for the protection and purification of carbonyl-containing organic compounds. Oximes are divided into aldoximes (derived from aldehydes) and ketoximes (derived from ketones). These compounds have the general formula (R)(R')C=N-OH [1-3]. Oximes are also used in the synthesis of other organic materials, including nitriles [4], nitro compounds [5-6], nitrones [7], amines [8], the synthesis of aza heterocycles [9-10], and are widely used as intermediates for the preparation of amides via Beckmann rearrangement [11-12], fungicides and insecticides [13], quinoline derivatives [14], isoxazoline [15], isoquinoline [16], etc. Oximes are also used as intermediates via Beckmann rearrangement [17-18] for the production of amides [19], chiral 3-α-sulfonyl oximes [20], 4-hydroxyaminochlorides, and nitrile oxides [21]. Oximes are crystalline compounds that exhibit basic properties in an acidic environment and produce salts in a basic environment [22-23], Figure (1-1). Oximes have diverse industrial applications, including their use as anti-skin-irritation agents, molding agents in the polymer industry, and chelating agents in the metal industry. They are also used as flame retardants and anti-skin-irritation agents in clinics [24-25]. Oximes have extensive synthetic and pharmaceutical applications, particularly in constructing chemical templates for synthesis in soil chemistry and pharmaceuticals [26]. Oximes are found in the chemical structure of several antibacterial agents and are used in the treatment of organophosphate poisoning and insecticides [27]. Oximes have been successfully employed as antioxidants [28-29]. Oximes are effective ligands in the formation of metal complexes [30].Oximes are effectively present in the structure of a number of sugars and fragrances [31] and cause vasodilation [32]. These compounds possess antimicrobial [33-34], anticancer [35], antidepressant [36], and antiviral [37] properties.

The synthesis of oximes from their corresponding carbonyl-containing organic compounds using hydroxylamine hydrochloride and wet silica gel. Keywords:

Oxime , Aldehyde , Ketone , SiO2 , NH2OH.HCl , Green Chemistry.