Carbonic chloride esters

Kohlensaure,/. carbonic acid carbon dioxide, -anhydrid, rt. carbonic anhydride (carbon dioxide), -ausscheidung,/. (Physiol.) c Tbon dioxide excretion, -bestimmer, m. apparatus for determining carbon dioxide, -brot, n, aerated bread, -chlorid, n. carbonyl chloride, -entwickelung,/. evolution of carbon dioxide, -ester, m. carbonic ester, -flasche, /. carbon dioxide cylinder, -gas, n, carbonic add gas (carbon dioxide), -gehalt, m. carbon dioxide content. 

Phosgene is a colorless gas at ambient temperature and pressure. Its odor has been described as similar to new-mown hay. Phosgene is manufactured from a reaction of carbon monoxide and chlorine gas in the presence of activated charcoal. The production of dyestuffs, isocyanates, carbonic acid esters (polycarbonates), acid chlorides, insecticides, and pharmaceutical chemicals requires phosgene. Manufacture of phosgene is approximately 1 million tons per year (y) in the United States, and more than 10,000 workers are involved in its manufacture and use. Manufacture of phosgene in the United States is... 

Acyl chlorides are converted in good yield into symmetrical carboxylic acid anhydrides upon treatment with dilute aqueous sodium hydroxide at -I0°C in the presence of a tetra- -butylammonium salt [76, 77]. Yields are considerably lower when Aliquat is used. In a similar manner, chloroformates and ethyl oxalyl chloride are converted into carbonic hemi-ester anhydrides. 

Further data from the polarography and cyclic voltammetry in dimethylformamide are given in Table 5.1 for a series of overall two-electron processes leading to cleavage of a benzyl-heteroatom bond. The first electron transfer step is of the dissociative electron transfer type leading to a benzyl radical. This radical is reduced firrther, at the working potential, to the benzyl carbanion. The carbanion fi om benzyl chlorides, esters, ethers, sulphides, sulphones and quaternary ammonium salts can be trapped by carbon dioxide to form phenylacetic acid [2]. Reac-... 

Many esteis of carbonic acid are known, e.g.. diethyl carbonate, ethyl ester of metacarbonic acid, (C HjO) CO. made by reaclion of ethyl alcohol and carbonyl chloride dimethyl carbonate. (CH Oi CO. methyl ethyl carbonate, dipropyl carbonate. (CiH-0) CO tetraethyl carbonate, ethyl ester of orthocarbonic acid, (CyHxO C. bp 158°C. 

All types of electrophiles have been used with 2-lithio-l,3-dithiane derivatives, including alkyl halides, sulfonates, sulfates, allylic alcohols, arene-metal complexes, epoxides, aziridines, carbonyl compounds, imines, Michael-acceptors, carbon dioxide, acyl chlorides, esters and lactones, amides, nitriles, isocyanates, disulfides and chlorotrialkylsilanes or stannanes. The final deprotection of the dithioacetal moiety can be carried out by means of different types of reagents in order to regenerate the carbonyl group by heavy metal coordination, alkylation and oxidation184 or it can be reduced to a methylene group with Raney-nickel, sodium or LiAIII4. 

What is the purpose of the carbonic acid ester chloride in the second step ... 

In the second step, a mixed carbonic acid ester is formed from the carbonic acid ester chloride and the alcohol moiety formed in the first step. 

Other derivatives of hydroxyl groups, shown to form without apparent complications, include phenylurethans,202 mixed203 and cyclic204 carbonates, diphenylphosphoric205 esters, and terminal 1-adamantoates206 cyclic sulfites204 are produced by the action of thionyl chloride. 

MAJOR USES Used in the production of dyes, isocyanate based polymers, carbonic acid esters, insecticides, acid chlorides and pharmaceuticals metallurgy used as a chemical warfare agent in World Wars I and II. 

Palladous chloride sodium chloride carbon Vinyl esters by transacylation... 

Berzelius represented C H CPO (C = i2) as a compound of carbon chloride and methyl ether 2CCP + C H 0, in which the latter preserves its property of forming esters with acids. Regnault also investigated the action of chlorine on methyl and ethyl ethers and other compounds. 

Acylating agents that have been employed are carbon dioxide, alkyl chloroformates, alkyl formates, add chlorides, esters, benzonitrile and dimethylformamide the expected acylation products from reaction with the above reagents were formed in each case. However, the N,N-dimethyl-amide derivatives of higher carboxylic acids did not yield acylated product as in the case of dimethylformamide . When R = H (equation 63), it was necessary to employ two equivalents of the lithiodithiane due to product enolate formation. 

Photocycloaddition of the allylic chloride 246 proceeds in 60% yield to give the desired photoadduct 247. Fragmentation of 247 with methanolic potassium carbonate generates ester 248. Reduction of the ester with lithium aluminium hydride, elimination of the chloride with DBU, and silylation of the primiary alcohol with tert-butyldimethylsilyl chloride (TBSCl), give 249 as a 7 1 mixture of the C-6 a [3 epimers in 35% yield from 247. Ingenol is derived from 247 in a 24-step sequence. 

Carbonic acid, HO OH is an unstable compound that decomposes spontaneously to produce carbon dioxide and water and, therefore, cannot be isolated. However, many acyl chlorides, esters, and amides that are derived from carbonic acid are stable compounds that have important applications. 

Figure 14. (a) Absorption polarization spectrum of pyrene-2-carbonic methyl ester (PCME). Solvent 1.85 1 by weight mixture of cholesteryl chloride and cholesteryl laurate 30°C). Concentrations lO M and 3.3. 10 M, respectively. The spectrum PIIE was taken with the linear polarizers P oriented parallel to the electric field E (or parallel to the optix axis L). 

The mechanism of the formation of (I) and (II) by debenzylation reaction was interpreted by Fles et al [3] as follows When one mole of aluminum halide is used it ionizes the covalent carbon-chloride bond and forms an ion pair (III) in which for steric reasons the CO residue cannot get close enough to its own sulfur to debenzylate it as easily as it can approach and debenzylate the sulfur of another molecule, thus forming poly-thiol-ester (II). 

Aromatic polycarbonates are prepared from various bisphenols, the most widely used being bisphenol A. The synthesis of aromatic polycarbonates is based on the reaction of bisphenol with carbonic acid derivatives such as phosgene, diphosgene, carbonic acid esters and chloroformic acid esters. The most important process for production of aromatic polycarbonate is the so-called interfacial process , first developed by Bayer. In this process, bisphenol A is phosgenated in the presence of methylene chloride in controlled conditions. 

Cinnamic acid can be readily esterified by the Fischer-Speier method without any risk of the addition of hydrogen chloride at the double bond. Proceed precisely as for the preparation of ethyl benzoate (p. 104), using 20 g. of cinnamic acid and 20 ml. of rectified spirit. When the crude product is poured into water, a sharp separation of the ester is not readily obtained, and hence the addition of about 10 ml. of carbon tetrachloride is particularly desirable. Finally distil off the carbon... 

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