Thesis (PH. D.)--Michigan State College of Agriculture and Applied Science, 1933. / Description based on print version record. Bibliography: p. 22.

Organic pigments were the source of coloring matters used by man until comparatively recent times. It is to be presumed that the first steps in the use of these pigments no dyes resulted from the accidental staining of the skin or fabric by a vegetable material. Prehistoric man, in order to decorate his implements or his person, or even to make records of his mode of life, used the materials with which he came in daily contact. Coloring materials included earth and vegetable substances found in flowers, seeds, berries, nuts, bark, wood, and roots, and less readily available coloring materials such as those of the heavy metals and those of animal origin. In addition to his knowledge of dyestuffs prehistoric man also developed a knowledge of tanning. He found that some of the vegetation that provided him with coloring matter would also preserve the skins he removed from the animals he killed as food and in doing so would render them suitable for clothing. Shortly after the preparation of the first synthetic dyestuff, the investigation of the natural yellow coloring matters was undertaken by Herzig. Herzig studied quercetin, derived from quercitron bark, and fisetin, which is present in young fuatic. About the same period, von Kostanecki submitted to examination chrysin, a coloring matter which had been isolated from the bud of the common popular. From the properties of this substance and the fact that when hydrolyzed it yields acetophenone and phloroglucinol, von Kostanecki represented it as a dihydroxy phenyl benzo-α-pyrone (I). von Kostanecki designated the mother substance of chrysin as being flavone (II), whereas the mother substance of fisetin (III) was flavonol (IV). The preparation of terephthalates was investigated in this work. The two methods considered were: (1) The condensation of terephthalaldehyde with the benzoates of o-hydroxyacetophenone, o,p-hydroxyacetophenone and o,m,p-trihydroxyacetophenone respectively in dry ethyl acetate using dry hydrogen chloride as the condensing agent, with subsequent debenzylation with 10 percent sodium hydroxide in an atmosphere of nitrogen. (2) The condensation of terephthalaldehyde with o-hydroxyacetophenone and o,p-hydroxyacetophenone using sodium hydroxide as the condensing agent. The dying properties of the compounds were investigated by precipitating the hydroxides of chromium, aluminum and iron salts as modante on woolen patches. The dyes of the latter two mordante were water fast, whereas those of the chromium mordent were not.

"The condensation of vapor onto a cooled surface is a phenomenon which can be difficult to quantify spatially and as a function of time; this thesis describes an ultrasonic system to measure this phenomenon. The theoretical basis for obtaining condensate film thickness measurements, which can be used to calculate growth rates and film surface features, from ultrasonic echoes will be discussed and the hardware and software will be described. The ultrasonic system utilizes a 5MHz planar piston transducer operated in pulse-echo mode to measure the thickness of a fluid film on a cooled copper block over the fluid thickness range of 50 microns to several centimeters; the signal processing algorithms and software developed to carry out this task are described in detail. The results of several experiments involving the measurement of both non-condensing and condensing films are given. In addition, numerical modeling of specific condensate film geometries was performed to support the experimental system; the results of modeling nonuniform fluid layers are discussed in the context of the effect of such layers on the measurement system."

A new method for running the Knoevenagel condensation in high yields has been developed and tested in eleven reactions with malononitrile. The dimer from cyclopentylidenemalononitrile was characterized and its structure was deduced from spectroscopy data. Reactions of the monomers with isoprene were carried out in sealed tubes and the ratio and yields of the isomeric products were determined by gas liquid partition chromatography. A para relationship of the cyano and methyl groups is favored in the products.Ball State UniversityMuncie, IN 47306

Thesis (M.S.)--Ohio University, March, 2007. / Title from PDF t.p. Includes bibliographical references.

Submitted in the fulfillment of the requirement for the Master's Degree in Chemistry,Durban University of Technology, 2017. / Knoevenagel condensation reaction is a useful protocol for the formation of C=C bond in organic synthesis. This protocol is extensively utilized by synthetic chemist to generate dynamic intermediates or end-products such as perfumes, polymers, pharmaceuticals and calcium antagonists. The reaction is catalyzed by bases such as ammonia, primary and secondary amines, quaternary ammonium salts, Lewis acids, catalysts containing acid-base sites, which are carried out under homogeneous conditions. This necessitates the use of organic solvent which generate the large volumes of solvent waste. From green chemistry perspective, solvent free heterogeneous catalysts have received considerable attention. Since, these heterogeneous catalysts not only avoid the use of organic solvents but also suppress side reactions such as self-condensation and oligomerisation leading in better selectivity and product yield. In recent years, therefore, the use of heterogeneous catalyst, their recovery and reusability are in demand in industry. The use of cobalt, iridium and platinum hydroxyapatites, MgO/ZrO2, MgO/HMCM- earlier been reported in the literature, and used as heterogeneous catalysts for the Knoevenagel condensation of aldehydes and esters. Based on these evidences, we envisioned that MgO and VMgO could also be used as heterogeneous catalysts for this reaction. Magnesium oxide was synthesized from three precursors, viz. magnesium nitrate, magnesium carbonate and magnesium acetate. Magnesium oxide prepared from magnesium nitrate precursor was found to be the optimum giving an 81 % product yield. Vanadium-magnesium oxide catalysts with different vanadium loadings; 1.5, 3.5 and 5.5 wt. %, were synthesized by wet impregnation of magnesium oxide with aqueous ammonium metavanadate solution. The synthesized catalysts were characterized by ICP-AES, FTIR, Powder XRD, SEM-EDX and TEM. The Knoevenagel condensation reactions between benzaldehyde and ethyl cyanoacetate were carried out in a 100 mL two-necked round bottom flask equipped with a reflux condenser, magnetic stirrer and a CaCl2 guard tube. An equimolar quantity (10 mmol) of substrates and 0.05g of catalyst were added to the flask and heated at 60 °C, stirred vigorously for the required time. The yields were determined using GC-FID equipped with a capillary column. Elemental composition of the catalysts (vanadium and MgO) was determined by ICP-AES. IR spectra of MgO showed that magnesium oxide was the only phase present in the catalysts prepared from different precursors. The 1.5 and 5.5 wt. % VMgO showed weak bands attributed to pyrovanadate and orthovanadate phases present in small quantities. The phases manifested more with the increase in the vanadium concentration (3.5 and 5.5 wt. % VMgO). The diffraction patterns of all the catalysts showed the existence of MgO and magnesium orthovanadate. The morphology of the catalysts with increasing vanadium was more affected by precursor treatment rather than chemical differences. Electron microscopy showed that the VMgO surface is only sparingly covered with vanadium and MgO showed stacked with large rounded particles. Good to excellent yields were obtained for the MgO catalysts: MgO(1) 68 %, MgO(2) 65 %, MgO(3) 72 %, MgO(P) 73 % and MgO(DP) 82 %. Excellent yields were obtained for the VMgO catalysts: 1.5VMgO 83 %, 3.5VMgO 91 % and 5.5VMgO 97 %. The 5.5VMgO catalyst was found to be the optimum catalyst and was further tested for it activity using different aldehyde substrates. Excellent yields of the products were obtained for benzaldehyde 97 %, nitrobenzaldehyde 94 %, bromobenzaldehyde 96 %, chlorobenzaldehyde 93 % and methoxybenzaldehyde 95%. / M