Triphosgene

Triphosgene (bis(trichloromethyl) carbonate (BTC), C3Cl6O3) is a chemical compound that is used as a safer substitute for phosgene, because, at room temperature, it is a solid crystal, as opposed to phosgene, which is a gas.[5] Triphosgene crystals decompose above 200 °C.[6]

Triphosgene
Triphosgen Strukturformel
Triphosgene-3D-spacefill
Names
Preferred IUPAC name
Bis(trichloromethyl) carbonate
Other names
BTC
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.046.336
Properties
C3Cl6O3
Molar mass 296.748 g/mol
Appearance white crystals
Density 1.780 g/cm3
Melting point 80 °C (176 °F; 353 K)
Boiling point 206 °C (403 °F; 479 K)
Reacts
Solubility *soluble in dichloromethane[1]
  • soluble in THF[2]
  • soluble in toluene[3]
Hazards
Safety data sheet SDS Triphosgene
GHS pictograms GHS-pictogram-skullGHS-pictogram-acid[4]
GHS signal word Danger
H314, H330[4]
P260, P280, P284, P305+351+338, P310[4]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Preparation

This compound is commercially available. It is prepared by exhaustive free radical chlorination of dimethyl carbonate:[5]

CH3OCO2CH3 + 6 Cl2 → CCl3OCO2CCl3 + 6 HCl

Triphosgene can be easily recrystallized from boiling hexanes to yield pure white crystals.

Uses

Triphosgene is used as a reagent in organic synthesis and is a less hazardous substitute for phosgene for a variety of chemical transformations including to bond one carbonyl group to two alcohols, and to convert an amine group into isocyanate.[5]

Safety

The toxicity of triphosgene is the same as phosgene since it decomposes to phosgene on heating and upon reaction with nucleophiles. Even trace moisture leads to formation of phosgene. Therefore, this reagent can be safely handled if one takes all the precautions as for phosgene.[7]

See also

References

  1. ^ Michelle A. Ouimet, Nicholas D. Stebbins, Kathryn E. Uhrich (2013). "Biodegradable Coumaric Acid-Based Poly(anhydride-ester) Synthesis and Subsequent Controlled Release". Macromol. Rapid Commun. 34 (15): 1231–1236. doi:10.1002/marc.201300323. PMC 3789234. PMID 23836606.CS1 maint: multiple names: authors list (link)
  2. ^ Tang, Shouwan; Ikai, Tomoyuki; Tsuji, Masashi; Okamoto, Yoshio (2010). "Immobilization and chiral recognition of 3,5-dimethylphenylcarbamates of cellulose and amylose bearing 4-(trimethoxysilyl)phenylcarbamate groups". Chirality. 22 (1): 165–172. doi:10.1002/chir.20722. PMID 19455617.
  3. ^ Zhou, Yuhan; Gong, Runjun; Miao, Weirong (2006-09-01). "New Method of Synthesizing N‐Alkoxycarbonyl‐N‐arylamide with Triphosgene". Synthetic Communications. 36 (18): 2661–2666. doi:10.1080/00397910600764675. ISSN 0039-7911.
  4. ^ a b c Sigma-Aldrich Co., Triphosgene. Retrieved on 2018-06-12.
  5. ^ a b c Dr. Heiner Eckert; Dr. Barbara Forster (1987). "Triphosgene, a Crystalline Phosgene Substitute". Angew. Chem. Int. Ed. Engl. 26 (9): 894–895. doi:10.1002/anie.198708941.
  6. ^ Dr. Heiner Eckert (2011). "Phosgenation Reactions with Phosgene from Triphosgene". Chim. Oggi Chem. Today. 29 (6): 40–46.
  7. ^ Suresh B. Damle (1993-02-08). "Safe handling of diphosgene, triphosgene". Chemical & Engineering News. 71 (6): 4.

External links

2-Chloropyridine

2-Chloropyridine is an organohalide with the formula C5H4ClN. It is a colorless liquid that is mainly used to generate fungicides and insecticides in industry. It also serves to generate antihistamines and antiarrythymics for pharmaceutical purposes.

Amino acid N-carboxyanhydride

Amino acid N-carboxyanhydrides, also called Leuchs' anhydrides, are reactive derivatives of amino acids. They are classified as N-carboxyanhydrides or NCAs. Typically these compounds are derived from amino acids by treatment with triphosgene. They are white solids, prone to polymerization upon treatment with nucleophiles.

Carbonate

In chemistry, a carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula of CO2−3. The name may also refer to a carbonate ester, an organic compound containing the carbonate group C(=O)(O–)2.

The term is also used as a verb, to describe carbonation: the process of raising the concentrations of carbonate and bicarbonate ions in water to produce carbonated water and other carbonated beverages – either by the addition of carbon dioxide gas under pressure, or by dissolving carbonate or bicarbonate salts into the water.

In geology and mineralogy, the term "carbonate" can refer both to carbonate minerals and carbonate rock (which is made of chiefly carbonate minerals), and both are dominated by the carbonate ion, CO2−3. Carbonate minerals are extremely varied and ubiquitous in chemically precipitated sedimentary rock. The most common are calcite or calcium carbonate, CaCO3, the chief constituent of limestone (as well as the main component of mollusc shells and coral skeletons); dolomite, a calcium-magnesium carbonate CaMg(CO3)2; and siderite, or iron(II) carbonate, FeCO3, an important iron ore. Sodium carbonate ("soda" or "natron") and potassium carbonate ("potash") have been used since antiquity for cleaning and preservation, as well as for the manufacture of glass. Carbonates are widely used in industry, e.g. in iron smelting, as a raw material for Portland cement and lime manufacture, in the composition of ceramic glazes, and more.

Chemical Agent Identification Set

Chemical Agent Identification Sets (CAIS), known by several other names, were sets of glass vials or bottles that contained small amounts of chemical agents. They were employed by all branches of the United States Armed Forces from 1928-1969 for the purpose of training in detection, handling and familiarization with chemical warfare. Most CAIS were destroyed in the 1980s but the U.S. Army Chemical Materials Agency still occasionally demilitarizes CAIS that are found buried.

Dimethylcarbamoyl chloride

Dimethylcarbamoyl chloride (DMCC) is a reagent for transferring a dimethylcarbamoyl group to alcoholic or phenolic hydroxyl groups forming dimethyl carbamates, usually having pharmacological or pesticidal activities. Because of its high toxicity and its carcinogenic properties shown in animal experiments and presumably also in humans, dimethylcarbamoyl chloride can only be used under stringent safety precautions.

Diphosgene

Diphosgene is a chemical compound with the formula ClCO2CCl3. This colorless liquid is a valuable reagent in the synthesis of organic compounds. Diphosgene is related to phosgene and has comparable toxicity, but is more conveniently handled because it is a liquid, whereas phosgene is a gas.

Functional group

In organic chemistry, functional groups are specific substituents or moieties within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of. This allows for systematic prediction of chemical reactions and behavior of chemical compounds and design of chemical syntheses. Furthermore, the reactivity of a functional group can be modified by other functional groups nearby. In organic synthesis, functional group interconversion is one of the basic types of transformations.

Functional groups are groups of one or more atoms of distinctive chemical properties no matter what they are attached to. The atoms of functional groups are linked to each other and to the rest of the molecule by covalent bonds. For repeating units of polymers, functional groups attach to their nonpolar core of carbon atoms and thus add chemical character to carbon chains. Functional groups can also be charged, e.g. in carboxylate salts (–COO−), which turns the molecule into a polyatomic ion or a complex ion. Functional groups binding to a central atom in a coordination complex are called ligands. Complexation and solvation are also caused by specific interactions of functional groups. In the common rule of thumb "like dissolves like", it is the shared or mutually well-interacting functional groups which give rise to solubility. For example, sugar dissolves in water because both share the hydroxyl functional group (–OH) and hydroxyls interact strongly with each other. Plus, when functional groups are more electronegative than atoms they attach to, the functional groups will become polar, and the otherwise nonpolar molecules containing these functional groups become polar and so become soluble in some aqueous environment.

Combining the names of functional groups with the names of the parent alkanes generates what is termed a systematic nomenclature for naming organic compounds. In traditional nomenclature, the first carbon atom after the carbon that attaches to the functional group is called the alpha carbon; the second, beta carbon, the third, gamma carbon, etc. If there is another functional group at a carbon, it may be named with the Greek letter, e.g., the gamma-amine in gamma-aminobutyric acid is on the third carbon of the carbon chain attached to the carboxylic acid group. IUPAC conventions call for numeric labeling of the position, e.g. 4-aminobutanoic acid. In traditional names various qualifiers are used to label isomers, for example, isopropanol (IUPAC name: propan-2-ol) is an isomer of n-propanol (propan-1-ol).

Isochem company

Isochem is a French chemicals company specialized in custom synthesis. The company's products and services are primarily destined for the following market sectors:

pharmaceuticals (APIs or active ingredients for medicinal products and intermediates),

cosmetics

specialty chemicals.The company operates from four production sites in France and also has: one industrial subsidiary outside France: Wychem in the UK.

Kuwajima Taxol total synthesis

The Kuwajima Taxol total synthesis by the group of Isao Kuwajima of the Tokyo Institute of Technology is one of several efforts in taxol total synthesis published in the 1990s. The total synthesis of Taxol is considered a landmark in organic synthesis.

This synthesis is truly synthetic without any help from small biomolecule precursors and also a linear synthesis with molecule ring construction in the order of A, B, C, D. At some point chirality is locked into the molecule via an asymmetric synthesis step which is unique compared to the other efforts. In common with the other efforts the tail addition is based on the Ojima lactam.

The 20 carbon frame is constructed from several pieces: propargyl alcohol (C1, C2, C14), propionaldehyde (C13, C12, C18), isobutyric acid (C15, C16, C17, C11), Trimethyl(phenylthiomethyl)silane (C10), 2-bromobenzaldehyde (C3 to C9), diethylaluminum cyanide (C19) and trimethylsilylmethyl bromide (C20)

Michler's ketone

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Phosgene

Phosgene is the organic chemical compound with the formula COCl2. It is a colorless gas; in low concentrations, its odor resembles freshly cut hay or grass. Phosgene is a valued industrial building block, especially for the production of urethanes and polycarbonate plastics. However, it is very poisonous and was used as a chemical weapon during World War I where it was responsible for 85,000 deaths. In addition to its industrial production, small amounts occur from the breakdown and the combustion of organochlorine compounds.

Takahashi Taxol total synthesis

The Takahashi Taxol total synthesis published by Takashi Takahashi in 2006 is one of several successful methods in taxol total synthesis. The method starts from geraniol and differs from the other 6 published methods that it is a formal synthesis (the final product is baccatin III which lacks the amide tail found in taxol itself) and that it is racemic (the product baccatin III is optically inactive). A key feature of the published procedure is that several synthetic steps (construction of rings A, B and C) were performed in an automated synthesizer on a scale up to 300 gram and that purification steps were also automated.

Wender Taxol total synthesis

The Wender Taxol total synthesis in organic chemistry describes a Taxol total synthesis (one of six to date) by the group of Paul Wender at Stanford University published in 1997. This synthesis has much in common with the Holton Taxol total synthesis in that it is a linear synthesis starting from a naturally occurring compound with ring construction in the order A,B,C,D. The Wender effort is shorter by approximately 10 steps.

Raw materials for the preparation of Taxol by this route include verbenone, prenyl bromine, allyl bromide, propiolic acid, Gilman reagent, and Eschenmoser's salt.

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