Schmitt modification

The Schmitt modification introduces a pressure reactor, typically an autoclave, whereby excess phenol and carbon dioxide do not escape and are efficiently converted to the hydroxy acid product. Using anhydrous sodium phenoxide, obtained by treatment of phenol with sodium metal, allows for a nearly quantitative isolation of salicylic acid after acidification. While the reaction is sensitive to water, it can be run in a variety of solvents, including aromatics, dioxane, pyridine, and DMF or under solvent-fi-ee conditions. ... 

Manufacture. Several methods have been described for the preparation of -hydroxyben2oic acid. The commercial technique is similar to that of salicylic acid, ie, Kolbe-Schmitt carboxylation of phenol. The modification includes the use of potassium hydroxide in place of caustic (51). The dried potassium phenate is heated under pressure, 270 kPa (2.7 atm) or more, with dry carbon dioxide at 180—250°C. The potassium salt [16782-08-4] of Nhydroxyben2oic acid forms almost quantitatively and can be converted to free acid by using a mineral acid. 

Example 2, the Marasse modification of the Kolbe-Schmitt reaction uses excess of anhydrous potassium carbonate in place of carbon dioxide ... 

Doebner modification of, 463, 465, 710, 711J, 719 Kofler hot bench, 82 Knorr pyrrole synthesis, 839j, 840 Kolbe-Schmitt reaction, 754, 755J, 774-776... 

Schmitt and his collaborators found that by judicious manipulation of the solvent environment they could roprecipitate soluble collagen in at least five different fibrous modifications. Briefly, they found that by adding increasing quantities of salt to a dilute acetic acid solution of soluble collagen, they could produce reconstituted collagens which showed (1) the normal 640 A polarized banding at 1 % NaCl, (2) an abnonnal, 210 A periodicity at 2% NaCl, and (3) no periodicity at 5% NaCl (see Fig. 15). 

A modification of the Kolbe synthesis which permits the immediate conversion of all the phenol into salicylic acid is known as Schmitt s synthesis. According to this method, as in the other, the sodium phenyl carbonate is first prepared this is then further heated in an... 

Carboxylation reaction the Kolbe-Schmitt (Marasse modification) reaction... 

Proposal for a Society of Systematic Zoologists September 8 1947, Schmitt Papers, box 60, folder SSZ Memoranda, Minutes of Meetings, Election Ballots, Financial Records, Committee Reports, 1947-1959. Another copy is located in Huhbs Papers, box 34, folder 60. This is the letter mentioned in Blackwelder, 1977 109). The first draft of this proposal, handwritten by Schmitt with modifications by Wharton, accompanies Wharton to Schmitt, August 14 1947, Schmitt Papers box 60, folder [SSZ] Correspondence, T-Z. ... 

Terpin n. Terpinol, 4-hydroxy-a,a,4-tri-methylcyclohexanemethanol. Additional names p-menthane-l,8-diol dipentenegly-col. Molecular formula C10H20O2. Molecular weight 172.26. Percent composition C 69.72%, H 11.70%, O 18.58%. Literature references from Merck Index, 13th edn. 2001 Both cis-and trans-modifications are known. The ds-compound is obtained most readily in the hydrated form, cis-terpin hydrate. Prepn of ds-form from oil of turpentine Hempel, Ann. 180, 71 (1876) Wallach, Ann. 230, 225 (1885) Schmitt, Mfg. Chemist 26, 350 (1955). From d-limonene Sword, /. Chem. Soc. 127y 1632 (1925). Prepn of trans-form from 1,8-cineole, oc-terpineol or ds-terpin hydrate. Matsuura et al. (1958) Bull Chem Soc Japan 31, 990. Lombard, Ambroise, Bull... 

The use of alkyl parabens as biocides in food, drug, and cosmetics manufacture is widespread, despite controversial claims of links to certain cancers. Industrial syntheses of paraben esters use the Kolbe-Schmitt reaction, principally via the corresponding potassium phenoxide, which favors /jcira-carboxylation. A modification that strongly favors para-subtitution involves potassium ethylcarbonate as a base, which gives a 93% yield of 4-hydroxybenzoic acid (33) from phenol at 225 °C under an atmosphere of 25 atm C02. Additional protocols using carboxylase enzymes under an atmosphere of 02 and with supercritical C02 have been reported to furnish para-carboxylation exclusively and in high yields. 

One of the most potent factors in the regulation of lAA biosynthesis may be lAA itself. lAA appears to suppress its own biosynthesis in decapitated coleoptiles (Anker 1973), and certain auxin-induced modifications of growth patterns have been attributed in part to effects on endogenous auxin production (Evans and Schmitt 1975, Evans et al. 1977). Red light-induced suppression of auxin production in coleoptile tips may result from a suppression of auxin movement out of the tip leading to feedback inhibition of auxin biosynthesis (Huisinga 1976). 

Schmitt H, Heirman M. 2007. Enzymatic modification of ledthin. 13 March 2007. US Patent 7189544. 

Choi J, Hui CM, Schmitt M, Pietrasik J, Margel S, Matyjazsewski K, Bockstaller MR (2013) Effect of polymer-graft modification on the order formation in particle assembly structures. Langmuir 29(21) 6452-6459... 

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