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The reaction of an organic substrate with phosgene is called phosgenation. [9] Phosgenation of diols give carbonates (R = H, alkyl, aryl), which can be either linear or cyclic: n HO−CR 2 −X−CR 2 −OH + n COCl 2 → [−O−CR 2 −X−CR 2 −O−C(=O)−] n + 2n HCl. An example is the reaction of phosgene with bisphenol A to form ...
Organic carbonates are not prepared from inorganic carbonate salts. [citation needed] Two main routes to carbonate esters are practiced: the reaction of an alcohol (or phenol) with phosgene (phosgenation), and the reaction of an alcohol with carbon monoxide and an oxidizer (oxidative carbonylation).
It can be made by reacting phosgene with ethanol, producing hydrogen chloride as a byproduct. Because chloroform can react with oxygen to form phosgene, chloroform can be stabilized for storage by adding 1 part (by mass) of ethanol to 100 parts (by mass) of chloroform, so that any phosgene that forms is converted into diethyl carbonate.
The sulfonium oxidations can be categorized into two groups: The methods discovered earliest rely on activated alcohols like alkyl tosylates (Kornblum oxidation) [2] or alkyl chloroformates (from reaction of alcohols with phosgene: Barton-Kornblum) [3] that react as electrophiles when treated with DMSO, liberating an oxygenated leaving group (e.g. OTs−).
A similar reaction involving thiols and selenols can yield the corresponding esters. [6] The alcohol reaction can also be used to form glycosidic bonds. [7] Similarly, an acid can be used in the place of an alcohol to form the anhydride, although dicyclohexylcarbodiimide is a more typical reagent.
It behaves like phosgene, to which it cracks thermally: OC(OCCl 3) 2 ⇌ 3 OCCl 2. Alcohols are converted to carbonates. Primary and secondary amines are converted to ureas and isocyanates. [6] [7] [9] [10] Triphosgene has been used to synthesize chlorides. [8] Some Alkyl chlorides are prepared by treating alcohols with a mixture of triphosgene ...
Traces of a toxic, colorless gas were found at the headquarters of Sweden’s security agency where a suspected gas leak last week forced authorities to evacuate some 500 people from the facility ...
The secondary alcohol in the 4-pentenal product of the aldol reaction, 9, was protected as an asymmetric carbonate ester. This group was removed in conjunction with the Red-Al reduction of ketone 12 (Scheme 2). Carbonate (cyclic) [1] phosgene, pyridine, dichloromethane, -78 °C to room temperature, 1 h