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Writing Chemical Equations
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
Write balanced equations based on the following descriptions: Sulfur dioxide gas reacts with oxygen gas to form sulfur trioxide gas.Calcium oxide solid plus water forms calcium hydroxide solid.Calcium carbonate solid decomposes to form calcium oxide solid plus carbon dioxide gas.Chromium (II) oxide solid is converted to chromium metal plus oxygen gas.Cobalt (II) nitrate in an aqueous solution plus sodium phosphate in an aqueous solution forms cobalt (II) phosphate solid plus sodium nitrate in an aqueous solution.Gold (III) chloride solid reacts with iron metal to form gold metal plus iron (III) chloride solid.Aluminum hydroxide solid decomposes to form aluminum oxide solid plus water.Lead (II) acetate in an aqueous solution reacts with potassium sulfate in an aqueous solution to form lead (II) sulfate solid plus potassium acetate in an aqueous solution.
Cleansing of Hair
Published in Dale H. Johnson, Hair and Hair Care, 2018
c. Alkyl Sulfonates. The alkyl sulfonates most commonly used in shampoos are alpha-olefin sulfonates (AOS). They are prepared by sulfonating alpha olefins with sulfur trioxide. Subsequent neutralization produces a mixture of alkene sulfonates and hydroxy alkane sulfonates. The chemical structures of these two sulfonates are as follows: where R is an alkyl chain with 12 to 14 carbons, and M is a cation such as sodium.
Corrosives
Published in Bev-Lorraine True, Robert H. Dreisbach, Dreisbach’s HANDBOOK of POISONING, 2001
Bev-Lorraine True, Robert H. Dreisbach
Sulfur dioxide reduces visibility by taking part in reactions between organic compounds and nitrogen oxides to form particulates. Oxidation to sulfur trioxide, which then combines with water to form small droplets of sulfuric acid, also reduces visibility.
Oxidative metabolism of razuprotafib (AKB-9778), a sulfamic acid phosphatase inhibitor, in human microsomes and recombinant human CYP2C8 enzyme
Published in Xenobiotica, 2021
Patrick Camilleri, Brandi Soldo, Akshay Buch, John Janusz
One di-oxygenated metabolite C3, m/z– 617.3, is also observed. It readily fragments to lose sulphur trioxide and methanol. The resulting fragment, m/z– 505.2, fragments further by loss of a di-oxidised thiophene fragment to provide m/z– 391.2 demonstrating that both oxidations have occurred in the thiophene ring. A possible metabolite is the thiolactone S-oxide. An analogous metabolite has been proposed previously (Dansette et al. 2009, 2010) and verified in the case of the thiophene-containing drugs clopidogrel and prasugrel where the thiolactone S-oxides of prasugrel react as bis-electrophiles with a variety of nucleophiles (Dansette et al. 2013). It is somewhat surprising that the thiolactone S-oxide of razuprotafib is sufficiently stable to be characterised by LC-MS/MS. It is possible that differences in the structures of razuprotafib versus prasugrel and clopidogrel are responsible. For razuprotafib, the thiazole and thiophene rings are connected by a single bond. In the tautomeric form (b) of the thiolactone S-oxide (Figure 10), the thiazole and thiophene are brought into conjugation and the thiolactone carbonyl exists in the ‘enol’ form. If tautomer (b) predominates, this could provide sufficient stability for direct observation of metabolite C3, the thiolactone S-oxide. For prasugrel or clopidogrel, where the thiophene ring is fused to substituted piperidines, no such stabilisation is possible.
Extraction and derivatisation of active polysaccharides
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Sulphur trioxide-pyridine method. The reaction conditions are mild and the properties of the reagents used are stable, but the substitution degree and recovery of sulphate are not very high. For example, Xiao et al.24 studied the factors affecting the reaction of SO3-pyridine method and Codonopsis pilosula polysaccharide (CJP) (experimental time, ambient temperature, and reagent ratio). The optimum reaction conditions were obtained as follows: the ratio of SO3-pyridine to polysaccharide solution was 4:1 (m/m), the experimental temperature at 80 °C, and the experimental time of 4 h. The final degree of substitution can be as high as 1.66%. Infrared spectra also show that the sulphation reaction of CJP is successful.
Xenobiotic C-sulfonate derivatives; metabolites or metabonates?
Published in Xenobiotica, 2018
From a non-biological standpoint, it is well known that sulfonic acids may be formed in the laboratory by reaction with sulfuric acid, sulfur trioxide, or a combination of the two as oleum. Indeed, when a compound is activated toward electrophilic attack, especially if it is an aromatic molecule, such a reaction may take place at low temperatures. In aqueous solution, some alkenes may react with sodium sulfite to give an addition across the double bond thereby forming a sulfonic acid salt and epoxides react with sulfite or bisulfite to yield hydroxyl sulfonate salts. Also, the initial phase in the reversible conversion of a naphthol to a naphthylamine (the “Bucherer-Lepetit reaction”) involves the addition of bisulfite to an aromatic double bond (Hoyle, 1991). Sulfonic acids may be formed also by reaction of carbonyl compounds with bisulfite to give “bisulfite addition compounds” (Lacosta & Martell, 1955; Wagner, 1929). Such addition occurs via a nucleophilic attack on the carbonyl group, which is electron deficient, by the lone pair occupying a hybrid orbital resident on the sulfur atom in bisulfite. Initially, a positively charged sulfur atom results but a simple proton transfer alleviates this situation (Rao & Salunke, 1984; Sykes, 1986) (Figure 6). Although the reaction of bisulfite with normal carbon–carbon double bonds appears difficult, especially if they are distanced from a carbonyl group (Nishimura & Iwase, 1976; Schenck & Danishefsky, 1951), it adds readily with ethylenic bonds in α,β-unsaturated compounds, whether they be aldehydes, ketones, acids or esters (Herke & Rasheed, 1992; Joslyn & Braverman, 1954; Morton & Landfield, 1952). Bisulfite undergoes addition to the pyrimidine ring structures of both uracil and cytosine (Hayatsu et al., 1970), across the double bond in the pyran (oxine) ring structure of anthocyanins (Berké et al., 1998) and via the double bond in the five-membered rings of prostaglandin A2 (Cho et al., 1977). However, many of these bisulfite addition reactions appear reversible and some adducts are unstable (Cerfontain, 1968), although other reports have suggested that C-sulfonates (not necessarily formed by the bisulfite route) are quite robust (Wagner & Reid, 1931).