CH3 175 83.06% 287-289ºC 4. -OCH3 191 86.03% 275-277ºC 5. 204 78.78% 295ºC Step-3 Synthesis of 2-Methyl benzoxazin -4(3H)-one53 (4) Anthranilic acid (0.1M, 18g) was taken in acetic anhydride and refluxed under anhydrous conditions for 4 hrs. Excess of acetic anhydride was then distilled off under reduced pressure. Obtained product was immediately used for next step.
This helps to indicate whether or not the reaction follows Markovnikov’s Rule, which states that the electrophile (E+) will add to the carbon involved in a double bond that produces the most stable carbocation. If the rule is followed, the reaction will proceed according to the mechanism in Figure 1. In the silver nitrate test, the alkyl bromide is added to AgNO3. The rate of precipitation with 2° should be faster than the solution with the 1° alkyl halide. In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone.
Squalene undergoes a two-step cyclization to yield lanosterol catalyzed by sequalene mono-oxygenase and sequalene 2, 3 epoxidase enzymes. Sequalene mono oxygenase is the second committed step in cholesterol biosynthesis and lead to the formation squalene 2, 3 epoxide. This enzymatic reaction require supernatant protein factor (SPF) and NADPH as a cofactor to introduce molecular oxygen as an epoxide at the 2, 3 position of squalene. The activity of supernatant protein factor itself is regulated by phosphorylation/dephosphorylation (Singh et al., 2003). Through a series of 19 additiona lreactions, lanosterol is converted to cholesterol.
P. agarwal and co-workers work for protein chemical modification by conducting a pictet-spengler reaction between aldehydes and alkoxyamines. This forms an oxyiminium ion as an intermediate that eventually undergoes intramolecular C-C bond with indole nucleophile to form an oxacarboline product. As compared to the oxime and hydrazone conjugates, the oxacarbolines are very much stable towards the hydrolysis under physiological relevant conditions as depicted by their experiment. In order to use this strategy for site specific chemical modification of formylglycine and glyoxalglycine-functionalized, they use an aldehyde-tagged variant of the Herceptin( a therapeutic monoclonal antibody). All the experiments performed by them showed that the Pictet-spengler reaction has a bright future in the research for the
4) Dehydration reaction between α and β carbons catalyzed by β-hydroxyacyl ACP dehydratase. 5) Reduction of trans-double bond by enoyl-ACP reductase utilizing NADPH as coenzyme. 6) Repetition of the above mentioned steps until palmitoyl-ACP is produced, the final product. This palmitoyl-ACP is then cleaved to palmitate and ACP by palmitoylthioesterase enzyme Regulation Of fatty acid
The N‟-2- (bromophenyl)-N,N-dimethylurea 16 underwent lithiation on the nitrogen to form a monolithio intermediate using MeLi, followed by bromine-lithium exchange using t-BuLi to give the dilithio species 17. 14 The intermediate 17 was then exposed to carbon monoxide to give 18, which after cyclization forms the intermediate 19, followed by loss of LiNMe2 to give 20, and finally after work up with dilute acid yielded the isatin product 1. 1 13 14 15 6 N O O 1) MeLi, 0 C CO Br N H O NMe2 2) t-BuLi, 0 C Li N O NMe2 Li C N Li O Li O NMe2 N O NMe2 O Li Li -LiNMe2 N H O O Li H3O + X X X X X X A rather versatile and novel two step synthesis of isatins was presented by Mironov in 2001 and allowed for the preparation of isatins containing electron withdrawing groups such as - CF3, -NO2, and -Cl. The method is based on the reaction between aromatic isocyanides and tertiary amines,15 where in the first step, 2-triethylammonio-3-arylaminoindolates 23 were obtained from the corresponding aromatic formamides 21 without isolation of the intermediate isocyanides 22. 16 Heating the 2-triethylammonio-3-arylaminoindolates 23 in excess thionyl chloride followed by hydrolysis led to the target
2.4.1 Hydrolysis In the first stage, complex organic compounds (such as carbohydrates, fats and proteins) are hydrolyzed, resulting in simpler compound (simple sugars like glucose) through enzymes produced by fermentive bacteria. In an anaerobic digestion process where organic polymers form a substantial portion of the waste stream to be treated, the hydrolyzing bacteria and their enzymes are of paramount importance because their activity produces the simpler substrates for the succeeding steps in the degradation sequence. The most common extra cellular hydrolytic enzymes are lipases, proteases, amylases and cellulases, which are excreted by hydrolytic bacteria (Zeikus 1980). Other extra cellular enzymes which may participate in the initial hydrolysis step of anaerobic digestion are the pectinolytic enzymes such as those elaborated by some Bacillus and Clostridium species, and the dextranases of, for example, Bacillus species. In sewage sludge, hydrolytic bacterial populations are usually high and generally comprise between 108 and 1010 bacteria per mL of sludge (Hobson et al 1974).
The condensation product between the aromatic aldehydes and the aromatic ketones are 1,3-diphenylprop-2-en-1-ones, which are commonly known as chalcones. If any other types of aldehydes and ketones are used, the product is frequently known as α,β-unsaturated ketones. Chalcones and α,β-unsaturated ketones have been captivating, the medicinal, synthetic, and applied chemists by virtue of their structural units (Figure 1) which have been gained many access to tailor the molecule suitably for wide range of applications in medicinal, synthetic, and applied chemistry.  The fluorine has the special topic of interest among the chemists as its introduction into the organic molecules leads to a dramatic changes in their physical and chemical properties.  The recent activities show a remarkable growth in fluorine chemistry as the chemists practiced to do polishing the organic molecules with fluorine to improve their properties, leading to widespread applications in medicinal,[4b,c,5] agrochemicals,
In the Part I of this proposed thesis, literature reviews on different environmentally benign protocols adopted in organic synthesis will be reported. Part II of the proposed thesis will describe Amberlite IR 120 as solid supported catalyst, multicomponent approach for convenient synthesis of tri and tetra substituted imidazoles. This part will be sub-divided by two chapters. In Chapter 1, the synthesis of tri substituted imidazoles by the catalysis of Amberlite IR 120H+ will be discussed whereas synthesis of tetra substituted imidazoles will be discussed in Chapter 2. In the Part III of the proposed thesis, Protic ionic liquid catalyzed substrate tuned green synthesis of 1,2-disubstituted and 2-substituted benzimidazoles with outstanding selectivity using Grindstone chemistry under solvent free condition will be described.