Ortho-acids

Each component of Jessner s solution has specific effects (Fig. 3.1). Salicylic acid (ortho hydroxy benzoic acid) is a beta hydroxy acid agent... 

Salicylic acid (ortho hydroxybenzoic add) is a beta hydroxy acid agent. It is a lipophilic compound which produces desquamation of the stratum corneum via removal of intercellular lipids [3] (see salicylic acid section). Given its keratolytic effects, it has become an increasingly popular superficial peeling agent. Salicylic acid peels induce injury via thinning or removal of the stratum corneum. In addition, salicylic acid potentially enhances the penetration of TCA. 

Aromatic aminosulfonic acids, which play a major role in connection with pigment lakes, are produced by sulfonating the corresponding nitro compound and then reducing it to an aminosulfonic acid. An alternative technique, known as baking process, involves exposing an amine/dihydrosulfate to a temperature of 200 to 300°C in order to effect rearrangement to p-aminosulfonic acid. Ortho-sulfonation prevails if the para position is occupied. In contrast to sulfonation techniques with sulfuric acid, this method avoids wastewater contamination with sulfuric acid. 

In order to use only a stoichiometric amount of alkyllithiums, a modified sulfonylhy-drazone leaving group containing no acidic ortho protons was required, such as 2,4,6-triisopropylbenzenesulfonyl (Trisyl 94) (equation 33). 

Monomer structure can affect the competition between cyclization and linear polymerization. For example, phthalic acid (ortho isomer) is more prone to cyclization than terephthalic acid (para isomer) at the very-low-molecular-weight end, for example, the dimer stage. The ortho structure makes more likely the conformations that are more favorable for cyclization. Stiff linear chains such as those formed in the reaction between an aromatic diamine and aromatic diacid chloride are much less prone to cyclization than the flexible chains formed from the corresponding aliphatic monomers. 

PHOSPHORIC ACID, META / PHOSPHORIC ACID, ORTHO 697... 

Phenylacetylene, 72 /ra X-TPHENYL-l,3-BUTAniENE, 75 a-PHENYL-a-CARBETHOXYGLUTARO-NITRILE, 80, 82 0-Phenylenediamine, 56, 86 a-Phenylglutaric acid, 82 a-PHENYLGLUTARIC ANHYDRIDE, 81 Phenylhydrazine, 90 Phenylmagnesium bromide, 97 Phenylsuccinic acid, 83 Phenylsuccinic anhydride, 85 Phosphoric acid, ortho-, 33, 34 Phosphoric anhydride, 33 Phosphorus oxychloride, Tl Phosphorus pentoxide, 22, 46 Potassium, 19, 20 directions for safe handling of, 20 Potassium lerl.-butoxide, solution of, 19... 

Carboxylic ortho esters can be regarded as ester-acetal derivatives of the hydrates of carboxylic acids (ortho acids). 

A manufacturing precast for producing ortho-phthalate otters derived from alkyl acid ortho-phthalatos and olefins has boon developed and demonstrated on the pilot plant scale. Process variables Include choice of reactants, stoichiometry, reaction kinetics, recycle of recovered materials and the fate of the perchloric add catalyst. Seme physical properties of the ortho-phthalate esters have been determined and severed of the esters have been evaluated as plasticizers for polyvinyl chloride. The composite data show that the acid-olefin esterification process provides commercially acceptable plasticizers for polyvinyl chloride. 

SILICIC. 1. Containing or pertaining to silicon. 2. Containing silicic acid (ortho) HrSiOa or silicic acid (meta) HiSiC or silicic acids of a higher degree of hydration (disilicic acids, trisilicic acids, etc.). 

N 15.15%. Three isomers are known. They are all expl and can be prepd by diazotizing the corresponding aniline sulfonic acid Ortho or 2-DU azo-, col cryst solid, expl weakly on heating si sol in w decomp in hot w or hot ale Meta or 3 -Diazo-, col prisms(from w), expl even by touching and on heating decomp in w at 60° or in hot ale and Para or 4-Diazo-, col ndls(from w) expl in dry state by heating(fl p 150°, Ref 2), on impact or friction sol in hot w or dil alkalies decomp in hot ale... 

As can be seen from Fig. 7.13, this method is also compatible with thiosalicylic acid ortho-allylthiosalicylic acid was obtained high yield (89% after 4 min). 

Mercaptobenzoic acids (ortho, meta and para isomers) were prepared in fair to good yields from the reaction of the chlorobenzoic acids with elemental sulfur and molten NaOH-KOH (1 1 molar ratio) at 270 "C for 3 min. Both 2- and 4-chloropyridine gave the mercaptopyridines by an analogous procedure.198 Use of selenium instead of sulfur gave poor yields and mixtures of isomeric products. 

The cyclopropyl-allyl rearrangement has been shown to proceed with nucleophilic assistance,87i232<233 and the intermediate allyl cation can be trapped by nucleophiles leading to synthetically useful derivatives. An example is the formation of an unsaturated acetal and the propiolic acid ortho ester (equations 92 and 93).232... 

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