Glycol acetate synthesis

Chemical Properties. Trimethylpentanediol, with a primary and a secondary hydroxyl group, enters into reactions characteristic of other glycols. It reacts readily with various carboxyUc acids and diacids to form esters, diesters, and polyesters (40). Some organometaUic catalysts have proven satisfactory for these reactions, the most versatile being dibutyltin oxide. Several weak bases such as triethanolamine, potassium acetate, lithium acetate, and borax are effective as stabilizers for the glycol during synthesis (41). 

Ethylene and propylene, the simplest alkenes, are the two most important organic chemicals produced industrially. Approximately 26 million tons of ethylene and 17 million tons of propylene are produced each year in the United States for use in the synthesis of polyethylene, polypropylene, ethylene glycol, acetic acid, acetaldehyde, and a host of other substances (Figure 6.11. 

Glycol.— This synthesis of di-hydroxy ethane was discovered by Wurtz, in 1854. The compound was named by him, glycol, because of its sweet taste. It is known also as ethylene glycol. The synthesis may be modified by substituting potassium acetate for the silver salt. Also, ethylene bromide is converted directly into the di-hydroxy compound, by boiling with dilute potassium carbonate. 

In some of the studies on the vinyl acetate synthesis from ethylene, high boiling products were reported (9, 10, 24, 25, 26). These included ethylidene diacetate (III), ethylene glycol monoacetate (IV) and ethylene glycol diacetate (V). Little attention has been given to the reactions by which these products are formed. No dioxygenated products have been reported previously when higher olefins have been used. 

In vinyl acetate synthesis in the presence of cupric chloride according to eq. (4), other by-products are mono- and diacetates of glycol and /5-chloroethyl acetate which under certain conditions become the predominant products [22]. In order to avoid side reactions, chloride-free catalyst systems such as Pd"/H9PMo6V6O40 have been described [23],... 

When media other than water are used, different but related processes operate. Thus, the oxidation of ethylene in acetic acid can be directed to give vinyl acetate, ethylene glycol acetate, or 2-chloroethyl acetate [9]. Similarly, the synthesis of acetals or ketals can be achieved in an alcoholic medium [10]. Although the oxidation of alkenes in such a medium is closely parallel to the Wacker process, the chemistry of these reactions is far beyond the scope of this section, which is limited to Wacker-type reactions in aqueous media, and will not be discussed here. 

Tetraisopropyl methylenediphosphonate intermediate, propoxylated surfactant Tetrahydroxypropyl ethylenediamine intermediate, propylene oxide Propylene Propylene glycol acetate intermediate, proton pump inhibitor synthesis 3-Methoxy-1-propanoi intermediate, PS piasticizers Methyi oieate... 

Synthesis of butyraldehyde glycol acetal from butyradehyde and glycol 89.5 [206]... 

J. Gong, etc. Synthesis of benzaldehyde ethylene glycol acetal from benzaldehyde and ethylene glycol under microwave irradiation 88.3 [215]... 

Li, D. Fu, H. Synthesis of Butyraldehyde Glycol Acetal with S04 - La /Ti02 as Catalyst. Flavour Fragrance Cosmet. 2004, 6, 11-13. 

Gong, J. Wang, Y. Qian, H. Synthesis of Benzaldehyde Ethylene Glycol Acetal under Microwave Irradiation Catalyzed by Rare-earth Solid Super Acid S04 /Ti02/La. Fine Chem. (Chin.) 2004, 21(12), 920-922. 

The procedure described is essentially that of Belleau and Weinberg and represents the only known way of obtaining the title compound. One other quinone acetal, 1,4,9,12-t6traoxadispiro[4.2.4.2]tetradeea-6,13-diene, has been synthesized by a conventional method (reaction of 1,4-cyclohexanedione with ethylene glycol followed by bromination and dehydrobromination ) as well as by an electrochemical method (anodic oxidation of 2,2-(l,4-phenylenedioxy)diethanol ). Quinone acetals have been used as intermediates in the synthesis of 4,4-dimethoxy-2,5-cyclohexadienone,. syw-bishomoquinone, - and compounds related to natural products. ... 

Due to its commercial importance, the synthesis of copper phthalocyanine (PcCu) is the best investigated of all the phthalocyanines. Copper phthalocyanine is prepared from phthalonitrile and copper(I) chloride without solvent137 and also in a melt of urea.229,277 Additionally, the insertion of copper into metal-free phthalocyanine in butan-l-ol and pentan-l-ol is possible. The copper salts used in this case are copper(I) chloride112 and copper(II) acetate.290 Starting from copper(II) acetate, copper phthalocyanine can also be prepared in ethylene glycol.127 As mentioned above, copper phthalocyanine often occurs as a byproduct of the Rosenmund-von Braun reaction. To increase the yield of the phthalocyanine the solvent dimethylformamide can be substituted by quinoline. Due to the higher boiling point of quinoline, the copper phthalocyanine is the main product of the reaction of copper(I) cyanide and 1,2-dibromoben-zene.130... 

Another synthesis, described in detail in Scheme 12, was devised specifically for the introduction of deuterium at both ends of l-deoxy-D-t/ireo-pentulose.21,22 Stannylene methodology was used twice, first for glycol splitting with phenyliodonium diacetate, under strictly neutral conditions (necessary to preserve the benzylidene acetal), and secondly to convert the sequence -CHOH-CD3 to CO-CD3 by brominolysis. The final, labeled pentulose was l-deo y-D-threo-(1-2H3, 5-2H)pentulose. 

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