Iranian Journal of Chemistry and Chemical Engineering
Volume:12 Issue: 1, May-Jun 1993

An efficient synthesis of the 1-hydroxy-2-(prpp- -enyl) 9-anthrone is described. Selective nitration of anthraquinone, reduction to the corresponding amine, diazotization and treatment by sulfuric acid solution afforded the 1-hydroxy-9, 10-anthraquinone in good yield as the key intermediate. Reaction with allyl bromide / K2CO3 and subsequent selective reduction accompanied by a Claisen rearrangement produced the title compound in high yield.

A solvent – extraction spectrophotometric technique is proposed as a new method for determination of trace quantities of vanadium. Sodium salt of 2-mercapto-pyridine-N-oxide (thione) forms a complex with vanadium instantaneously. The purple 1:2 complex is formed at pH 2.3, easily extracted in chloroform and shows strong absorbance at 500nm. The extracted complex is found to obey Beer’s law in the concentration range of 0.3-18mgmL-1 vanadium. The molar absorptivity of vanadium thione complex is 2.63×103 L.mol-1.cm-1 with a detection limit of 0.1mgmL. The proposed method offers the advantage of sensitivity and relative freedom from interferences compared to the existing methods. This method is applied in the determination of vanadium in rutile.

The interaction of histone H2B and dodecyl trimethyl ammonium bromide (DTAB) was studied via equilibrium dialysis method at two different temperatures, at pH 6.4 in phosphate buffer. The binding data were used to obtain the Gibbs free energy of interaction, which is interpreted in terms of a theoretical model based on the Wyman binding potential. The data were then used to obtain the enthalpy of interaction from the temperature dependence of the equilibrium constants by the van’t Hoff relation, in order to get a better picture of the thermodynamics of the interaction. The enthalpy of unfolding is found to be consistent with Hill plots which are good estimation of the cooperativity of the system.

Using a – tetralone, as starting material, a series of phencyclidine analogues were synthesized. This ketone was reacted separately with ethylmagnesium bromide, P-methoxyphenylmagnesium bromide and P-methylphenylmagnesium bromide. The resultant alcohols were treated with a suspension of NaN3, and CCl3COOH in CHCl3. The azides were subsequently reduced with LiAlH4 in dry ether to their primary amines. Cyclization of these amines with 1,5-dibromopentane and 1,4-dibromobutane gave tertiary amines.

Deposition of behenic acid (B-A) mono and bilayers onto gold coated surfaces was performed by Langmuir – Blodget dip-casting technique. Surface plasmon resonance (SPR) and ellipsometry methods were employed for investigation of the monolayer and bilayer films. The adsorption of the biologically important molecule Concanavalin A (Con A) from bulk solution to these monolayers and bilayers as well as the interaction between deposited Con A with dextran molecules in the presence of Ca2+ and Mn2+ ions was investigated. The results obtained, show that no significant interaction occurs between the adsorbed Con A and dextran in the case of B.A bilayer, While a significant binding takes place in the monolayer.

Zinc chlorochromate nonahydrate is easily prepared from the aqueous solution of chromium trioxide and zinc chloride in quantitative yield. This oxidant, in methylene chloride and at room temperature oxidizes thiols to their disulfides. Acetals and thioacetals are deprotected to their corresponding carbonyl compounds. Sulfides are selectively converted to their sulfoxides or sulfones. Aryloxyranes undergo carbon – carbon bond cleavage and produce the corresponding aldehydes. Cyclohexane oxide yields 2 hydroxy cyclohexanone. Trimethylsilyl ethers are also deprotected and converted to the corresponding carbonyl compounds in high yields.

An extraction – spectrophotometric method for the determination of traces of copper (ii) is described. The method is based on the quantitative extraction of copper as tetrabutylammonium tetrahiocyanato copper (II) into methyl isobutyl ketone, followed by spectrophotometric determination, using eriochrome black T as a metallochromic indicator. The red – violet mixed complex of copper absorb at lmax=570nm with a molar absorptivity of 4.4×104 Lmol-1cm-1. The Sandell’s sensitivity for 0.001 absorbance unit is 1.4ngcm-2. The method is simple, sensitive and free of interferences from many anions and cations.

a-Hydroxy ketones with an aromatic and aliphatic substituent were prepared with condensation of aromatic and aliphatic aldehydes in the presence of polymer-bound thiazolium salt.