Fragrances industrial manufactures

Methyl benzoate, [93-58-3], CTfCOOCI Ig, bp, 198—200°C at 101.3 kPa d [ , 1.094 n], 1.5205. Insoluble in water, this is a colorless, transparent liquid solidifying at about 15°C. Methyl benzoate is prepared by the direct esterification of benzoic acid and methanol. It is used in the fragrance industry and in the production of other benzoate esters (via transesterification). A technical-grade methyl benzoate is available as a by-product in the manufacture of dimethyl terephthalate [120-61 -6]. 

This is probably the single most important material used by the fragrance industry. Several million pounds are used annually, mainly in soaps and detergents. The principal method of manufacture shown in Figure 10 is by hydration of citronellal via the bisulfite addition product (2). The aldehyde moiety must be protected before hydration. A second manufacturing process starts with citronellol which is hydrated under acid conditions. The primary alcohol end of the molecule is then dehydrogenated catalytically or by oxidation to the aldehyde. 

Ih the mid-1950 s, Hoffmann La-Roche offered synthetic linalool and its esters to the fragrance industry (5). This was another revolutionary step in the replacement of natural products with synthetics. Linalool was an intermediate in Roche s manufacture of synthetic isophytol for Vitamin E. For several years perfumers were reluctant to use chemically pure synthetic linalool and its esters in place of materials isolated from essential oils. Finally, economics prevailed and today the amount of synthetic linalool and its esters used far exceeds the traditional "linalool rich" essential oils. 

The fragrance industry has made use of small molecule epoxy furans. The rose flavone epoxide 78 and rose isoflavone epoxide 79 are components of a perfume that is mild and gives refreshing feels <1996JPP8092588>. Perfumes containing these components can be used in the manufacture of cosmetics, air fresheners, and other products. 

Nevertheless, under the conditions of good manufacturing practice (GMP) the chirality evaluation of linalool has proved to be a reliable indicator in the authenticity control of lavender, bergamot, and orange oils. This fact will be of considerable importance in the quality assurance for the flavour and fragrance industry. 

The selective hydrogenation of 4-t-butyl phenol is of commercial interest for the manufacture of cis-4-t-butyl cyclohexanol (1), which as is an important product used in the Flavours and Fragrance industry. The reaction is also of interest in that several confounds are potential products of the reaction, namely the cis and trans-t-butyl cyclohexanol as well as the 4-t-butyl cyclohexanone. Previous studies (2, 3) have shown rhodium to be the most active catalyst for this reaction and... 

The esterification of cyclic olefins with carboxylic acids, such as dicyclopentadiene or naturally occurring terpenes, yields compounds of industrial value. For instance, the esterification of dicyclopentadiene with saturated carboxylic acids, such as acetic acid, leads to a starting material for the flavour and fragrance industry, as well as the resulting alcohols in consecutive hydrolysis. By using unsaturated carboxylic acids as nucleophiles, the resulting esters are also useful compounds in the manufacture of binders for polymer concrete (Scheme 1). ... 

First Industrial Manufacturers of Essential Oils, Flavors, and Fragrances... 

The rapid development of the fragrance and avor industry in the nineteenth century was generally based on essential oils and related natural products. In 1876, however, Haarmann and Reimer started the rst production of synthetic aroma chemicals—vanillin and then coumarin, anisalde-hyde, heliotropin, and terpineol. Although aroma chemicals made a revolution in fragrances with top discoveries in the twentieth century, for many decades both avors and fragrances were manufactured with constituents of natural origin, the majority of which were essential oils. 

This brief and certainly incomplete look into the history of industrial usage of essential oils as a-vor and fragrance ingredients shows that the real industrial scale of avor and fragrance industry developed in the second half of the nineteenth century together with transformation of manufacture into industry. 

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