Iso-vanillin

The installation of the amine functionality at C5 is accomplished by mesylation of 41 followed by azide displacement to give 44 (71% yield over four steps). The P-aminopropanamide 13 is then introduced directly to the lactone under 2-hydroxypyridine catalysis to give the penultimate intermediate 45. Reduction of the azide and isolation as the hemifumarate salt provides aliskiren hemifiimarate (l).37 Based on the information disclosed to date, the synthesis of aliskiren is accomplished with an overall yield of 14% from iso vanillin 14 with a longest linear sequence of 15 steps. Given the complexity of aliskiren, this is a remarkably efficient process, and it should be noted that this analysis likely only establishes a lower limit of efficiency, as further optimization of the route on a manufacturing scale is expected. 

Hydroxy-4-methoxy-benzylalkohol (Isovanillinalkohol)5 20 g 3-Hydroxy-4-methoxy-benzaldehyd (Iso-vanillin) werden in 100 ml Methanol gelost und mit Palladium/Tierkohle [0,2 g Palladium(II)-chlorid auf 0,8 g Kohle] hydriert. Die Reduktion setzt sofort ein. Die Wasserstoff-Aufnahme ist sehr rasch und innerhalb 1 Stde. beendet. Man filtriert und dampft das Filtrat i. Vak. ein. Der kristalline Riickstand wird aus siedendem Toluol umkristallisiert Ausbeute 90-95% d.Th, F 132° (Nadeln). 

Li X, Deng S, Mu G, Qu Q (2007) The synergistic inhibition etfect of rare earth cerium(IV) ion and iso-vanillin on the corrosion of cold rolled steel in 1.0 M H2S04 solution Materials Letters, 61,11-12,2514-2517. 

Vanillin (4-hydroxy-3-methoxy-benzaldehyde) was substituted for iso-vanillin, with the same results. While the Ce and vanilhn were added separately to the sulphuric acid, UV-Vis analysis of the individual components compared with the mixture produced vastly different spectra. The authors claim a Ce-vanillin complex formed in the acid solution, and surface characterization data are put forward to support the presence of both Ce and vanillin in the protective film formed on the surface of the steel. Similar results were observed in IM hydrochloric acid. " ... 

Potentiodynamic polarization scans of cold rolled steel in Ce and iso-vanillin inhibited solutions of 1.0 M... 

For the manufacture of vanillin, eugenol is first isomerised to iso-eugenol, in which a rearrangement in the side chain has taken place. 

Another perfume that may be included in the sweet floral family, and that has enjoyed great success in the United States, is Vanderbilt, created in 1981. Built around a combination of fresh citrus top notes, orange blossom, and tuberose, Hedione, methyl ionone, heliotropin, vanillin, and musk ketone, with iso E super coming in as the woody note, it lacks much of the heavy floral sweetness of the other perfumes in the group, lacking most of the eugenol with little or no ylang or coumarin. 

In Casmir the same technique is used but in an oriental context. The formula is constructed around large amounts of Hedione (20%), Galaxolide and ethylene brassylate, a combination of Iso E super and Vertofix, and vanillin (14%), which together make up some 80% of the formula. In deference to the oriental character linalool and linalyl acetate are present to provide a top note with traces of rose, vetiver, and patchouli, in the background. A strong fruity note, characteristic of many modem American perfumes, is also included. 

The conversion of eugenole into iso-eugenole and of safrole into iso-safrole is accomplished by boiling with alcoholic potassium hydroxide. The oxidation products of these ethers are other important essential oil constituents. Eugenole yields the corresponing aldehyde which is known as vanillin, the chief constituent of vanilla beans from which vanilla extract is made. Safrole by oxidation yields a compound known as piperonal also as heliotropine. It has the odor of heliotrope flowers and is used as artificial heliotrope essence. These latter compounds and also constituents of other essential oils will be considered in detail later in their proper chemical relationship (p. 66i, etc.). 

Heliotropin is prepared commercially by the synthesis given above from safrole through iso-safrole. It is used in perfumes on account of its very pleasant odor of heliotrope flowers. It forms crystals, m.p. 37°, b.p. 263°. By boiling with water it hydrolyzes and yields protocatechuic aldehyde just as vanillin does. It also yields oximes and hydrazones which are characteristic. 

In a stainless-steel beaker of approximately 3-1. volume (180 mm. by ISO mm.) (Note 1), equipped with an efficient mechanical stainless-steel stirrer and heated by an electric hot plate, are placed 84 g. (2 moles) of 97% sodium hydroxide pellets, 332 g. (5 moles) of 85% potassium hydroxide pellets (Note 2), and SO ml. of water. The mixture is stirred and heated. When the temperature of the fluid mixture reaches 160°, 152 g. (1 mole) of vanillin is added in portions over a period of 2.5-3 minutes at a rate sufficient to maintain the reaction (Note 3). The temperature at this point is 190-195°. Stirring is continued and heat is applied until the temperature reaches 240- 245° (Note 4). The temperature is maintained at 240-245° for 5 minutes. The hot plate is removed, and the mixture is allowed to cool with stirring. When the mixture has cooled to about 150-160°, 1 1. of water is added, and the mixture is stirred until all the fusion mixture is dissolved. The solution is transferred to a 4-1. beaker, another 500 ml. of water is added, and sulfur dioxide gas is introduced for 2 minutes (Note 5) the mixture is Ihen completely acidified... 

Vanillin can be formed by electrolytic oxidation of the sodium salt of iso-eugenol. According to the process of F. von Heyden Nchfg. a 15 per cent, alkaline solution of the sodium salt forms the anolyte, and the cathode compartment is filled with caustic soda solution (10-20 per cent.). The temperature is maintained at 60° C., and the lead peroxide anode evidently acts as a catalyst, since with platinum the discharged oxygen is evolved without effecting the oxidation —... 

The materials used were Polysulfone (PSf, Sigma-Aldrich, Spain, transparent pellets of Mw = 16,000) as polymer, dimethylformamide (DMF, Scharlab, reagent grade ACS-ISO) as solvent, vanillin (Acros organics, 99% pure) as core material and distilled water as nonsolvent. 

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