Figure 1 shows the diluted and actual concentrations of salicylic acid, the concentration and log value of aspirin at various times. Time / min C1 / mol L-1 C2 (actual) / mol L-1 [Aspirin] / mol L-1 ln([Aspirin]) 0 1.996*10-5 9.98*10-4 0.0225 -3.79 10th 6.925*10-5 3.46*10-3 0.0200 -3.91 20th 1.135*10-4 5.68*10-3 0.0178 -4.03 30th 1.372*10-4 6.86*10-3 0.0166 -4.10 40th 1.653*10-4 8.27*10-3 0.0152 -4.18 50th 1.828*10-4 9.14*10-3 0.0144 -4.24 60th 1.953*10-4 9.77*10-3 0.0137 -4.29 Figure 1. A graph of ln([aspirin]t) against time (min) was plotted. The gradient gave the value of K, the rate constant for the reaction. Figure 2 shows the plotted graph Figure 2.
Figure 2: Chemical structure of Ephedrine Hydrochloride. References 1.Gaddum, J. Ephedrine. British Medical Journal 1, 713 (1938). 2.Bergin, R. Refinement of the structure of (-)-ephedrine hydrochloride. Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry 27, 381--386 (1971).
It is soluble in hexafluroisopropanol, hexafluroacetone and chloroalcohols. Whereas, chitosan is deacetylated product of chitin, is soluble in acetic acid and formic acid. The nitrogen content of chitin is mostly acetylated group, whereas, nitrogen in chitosan is mostly in the form of primary aliphatic amino group. Preparative procedure of chitin and chitosan are shown in Fig, 2 (a) Chitin and chitosan are excellent functional materials for biomedical applications because of their high biocompatibility, biodegradability, antibacterial activity, non-antigenicity and high adsorption properties that makes them appropriate for tissue engineering (Fig. 2 (b))[15-18].
3.3. Synthetic methodologies for dihydropyrimidinones 3.3.1. Classical method Scheme-1: The conventional method for the synthesis of DHPMs is the one-pot three-component reaction of benzaldehyde, ethyl acetoacetate and urea in the presence of an acid catalyst. The product of this novel one-pot, three components synthesis that precipitated on cooling of the reaction mixture was identified as 3,4-dihydropyrimidin-2(1H)-one and this reaction came to be known as “Biginelli reaction”, or “Biginelli condensation”, or “Biginelli dihydropyrimidine synthesis” after the name of its inventor “Pietro Biginelli”.1 Mechanism Forty years after Biginelli’s initial report, the first mechanism for the synthesis of DHPMs was conducted by Folkers and Johnson
Synthesis of 3-[5-(4-substituted) phenyl-1,3,4-oxadiazole-2yl]-2-styrylquinazoline-4(3H)-ones was carried out by following steps: Step 1: Synthesis of 4- substituted benzaldehyde semicarbazon51(2) Semicarbazide Hydrochloride (0.1M) and sodium acetate (0.2M) was added and dissolved in 15-20ml of distilled water placed in flat-bottomed flask. In a separate beaker containing required aromatic aldehyde (1) (0.1M) was dissolved in aldehyde free alcohol. This ethanolic aromatic aldehyde solution was added slowly to the solution of semicarbazide hydrochloride. The precipitate, which gets separated, was filtered, dried and recrystallised from 95% hot ethanol. Table 1: Quantity of aldehydes taken S. No.
PICRIC ACID AR ALDRICH 12. POTTASSIUM IODIDE AR ALDRICH 13. AMMONIA AR ALDRICH 14. BROMINE WATER AR ALDRICH The following tests were carried out. Tests for alkaloids a. Morquies test: For detecting the alkaloids 2-3 gms of the sample was ground with sufficient chloroform to make slurry.
Lee et al. (2003) reported a new method for the determination of the methyl, ethyl and isopropyl esters of methanesulfonic acid, and of dimethyl sulfate. Derivatisation with aqueous sodium thiocyanate gives a mixture of the corresponding alkylthiocyanates and alkylisothiocyanates which, unlike the underivatised analytes, are readily analysed by GC. On-column isomerisation is negligible. These lower alkyl derivatives are sufficiently volatile for static reaction headspace analysis, and detection limits obtained by electron impact MS are below 0.05 µg ml−1 with respect to the injection solution.
1.3.6 Sakai synthesis N. Sakai et al,  have synthesized various indole derivatives (17) via indium-catalyzed cyclisation of 2-ethynylanilines in good yields [Scheme 1.7]. Scheme 1.7: Indium catalyzed synthesis of indole. 1.3.7 Zhu et al synthesis A mild preparation of substituted indole (18) from simple aromatic precursors using (trimethylsilyl) diazomethane was reported by L. Zhu et al,  [Scheme 1.8]. Scheme 1.8: Synthesis of indole from 2-amino
The range of the first trial is 89.5oC – 91oC, and the range of the second trial is 90.5oC – 93.5oC. According to page 58 in the lab manual, the closest possible substances it could be are t-butyl alcohol, cyclohexene, tetrahydropyran or isooctane. PubChem says that the molecular formula for t-butyl alcohol is C4H10O, and it has a boiling point of 83oC. Cyclohexane has a boiling point of 83oC also and a molecular formula of C6H10.Tetrahydropyran has a boiling point of 88oC. PubChem states the molecular formula for tetrahydropyran to be C5H10O.