Isolates products

The step is exothermic it leads from the carbocation intermediate to the isolated products of the reaction... 

Each chlorine atom formed m the initiation step has seven valence electrons and IS very reactive Once formed a chlorine atom abstracts a hydrogen atom from methane as shown m step 2 m Figure 4 21 Hydrogen chloride one of the isolated products from... 

If the temperature is not kept below 25°C dunng the reaction of primary alcohols with p toluenesulfonyl chloride in pyndine it is sometimes observed that the isolated product is not the desired alkyl p toluenesulfonate but is instead the corresponding alkyl chlonde Suggest a mech anistic explanation for this observation... 

A dihaloalkene is an intermediate and is the isolated product when the alkyne and the halogen are present m equimolar amounts The stereochemistry of addition is anti... 

Reaction with primary amines (Section 17 10) Isolated product is an imine (Schiff s base) A carbinolamine inter mediate is formed which undergoes de hydration to an imine... 

Reaction with secondary amines (Sec tion 17 11) Isolated product IS an en amine Carbinolamine intermediate can not dehydrate to a stable imine... 

Acetophenone is the isolated product it is formed from its enol by proton transfers ... 

Nitrosation of amines is best illustrated by examining what happens when a sec ondary amine reacts with nitrous acid The amine acts as a nucleophile attacking the nitrogen of nitrosyl cation The intermediate that is formed m the first step loses a pro ton to give an N nitroso amine as the isolated product... 

A competing side reaction is chlorate formation, 3 CIO — 2 Cl + CIO3, which decreases the yields of dibasic magnesium hypochlorite [11073-21-5] and of evolved chlorine. The difficult to filter slurries can be dried with Httle loss to a white, powdery soHd with av CI2 in the range of 52—59%. The yields of isolated product and recovered chlorine are typically about 40% each, while product solubiUty loss and chlorate formation amount to about 10% each. 

Canada has no known basic producers of chlorobenzene. There is one company that isolates small quantities of ortho and para from purchased mixed dichlorobenzenes. Some of the isolated product is exported. The primary portion of Canada s chlorobenzenes comes from the United States. 

Phenyl isocyanate reacts with (82) to form (83) by ring enlargement (74JOC948). Reaction of oxaziridines with diphenylketene proceeds less obviously. Isolated products (84) and (85) contain only the R—N group of the starting material (69TL263). 

The mechanism of the hardening proeesses has been investigated by Zinke in Austria, von Euler in Sweden and Hultzsch in Germany using blocked methylol phenols so that only small isolable products would be obtained. 

A similar transformation results when trimethylsilyloxy-substituted allylic halides react with silver perchlorate in nitromethane. The resulting allylic cation gives cycloaddition reactions with dienes such as cyclopentadiene. The isolated products result from desilyla-tion of the initial adducts ... 

High vacuum sublimation of the 3-monobenzoate of (32) or tosylchloride dehydration gives 3/ -benzoyloxy-7-methylenecholest-5-ene (33). The configuration of (32) is probably as shown since 7a-hydroxy steroids dehydrate readily to yield homoannular dienes. In an analogous reaction ethyl and iso-butyl Grignard reagents give alkylidene compounds as the only isolated products. 

Similarly complex is the fluorination of the Ihtes methylpyridines (a-, ()-, and 7-picolmes) with cesium tetrafluorocobaltate. 2-Methylpyridme was fluorinated at 270 °C for 180-200 mm, 3- and 4-methylpyridmes were fluorinated at 330 to 340 °C for 150 min All of them afforded the respective polyjluorinated pyridines and perfiuoro-1,2-, 1,3-dimethyl-, and 1-ethylpyrrolidine In addition, perfluoro-2-aza-2-hexene and bis(tnfluoromethyl)amine were isolated m variable yields [27] All the isolated products of the fluorination of 3-methylpyridme (3-picoline) are shown in equation 9. 

Most of the straight-chain aliphatic aldehydes react with sulfur tetrafluoride in the usual manner to give the expected 1,1-difluoroalkanes as the only isolable products, reasonable yields are obtained in a narrow temperature range, from -20 to 40 C. An exception is butyraldehyde, which, when treated with sulfur tetrafluoride below 0 C, gives, in addition to 1,1-difluorobutane, considerable amounts of bis(l -fluorobutyl) ether [169] (equation 81)... 

An ipso attack on the fluorine carbon position of 4-fIuorophenol at -40 °C affords 4-fluoro-4-nitrocyclohexa-2 5-dienone in addtion to 2-nitrophenol The cyclodienone slowly isomenzes to the 2-nitrophenol Although ipso nitration on 4-fluorophenyl acetate furnishes the same cyclodienone the major by-product is 4 fluoro-2,6-dinitrophenol [25] Under similar conditions, 4-fluoroanisole pnmar ily yields the 2-nitro isomer and 6% of the cyclodienone The isolated 2 nitro isomer IS postulated to form by attack of the nitromum ion ipso to the fluorine with concomitant capture of the incipient carbocation by acetic acid Loss of the elements of methyl acetate follows The nitrodienone, being the keto tautomer of the nitrophenol, aromatizes to the isolated product [26] (equation 20) Intramolecular capture of the intermediate carbocation occurs in nitration of 2-(4-fluorophenoxy)-2-methyIpropanoic acid at low temperature to give the spiro products 3 3-di-methyl-8 fluoro 8 nitro-1,4 dioxaspiro[4 5]deca 6,9 dien 2 one and the 10-nitro isomer [2d] (equation 21)... 

Arylsulfmic acids are perfluoroalkylated under the conditions, but the yield IS low [77 (equation 70) The isolated product is an aryl perfluoroalkyl sulfone. The possible formation of a perfluoroalkyl aryl sulfinate intermediate, arising from an 0-alkylation reachon, has not been discussed. 

Unless otherwise noted, a shghl excess of halogen and three-fold excess of KF was used NMR yield versus PhCF3 When two values are given, the second value is the isolated yield Products were identified either by spiking with an authentic sample or by combinanon of IR and mass spectra data of the isolated products. 

The yields refer to pure isolated products, unless otherwise cited The values were measured by F NMR and represent the ratios of the lower field peaks to the higher field peaks due to the a methine fluonne in an isomeric mixture ot the product... 

Yields are of pure isolated products. The ratio was determined by F NMR... 

Pertluoroallene is also quite reactive in its additions to nitrones [20], diazoalkanes [20] and sydnones [19] With sydnones, the isolated product derives from a fluoride ion rearrangement of the primary adduct (equation 21)... 

FIGURE 22.5 The diazonium ion generated by treatment of a primary alkylamine with nitrous acid loses nitrogen to give a carbocation. The isolated products are derived from the carbocation and include, in this example, alkenes (by loss of a proton) and an alcohol (nucleophilic capture by water). 

Reactant and product structures. Because the transition state stmcture is normally different from but intermediate to those of the initial and final states, it is evident that the stmctures of the reactants and products should be known. One should, however, be aware of a possible source of misinterpretation. Suppose the products generated in the reaction of kinetic interest undergo conversion, on a time scale fast relative to the experimental manipulations, to thermodynamically more stable substances then the observed products will not be the actual products of the reaction. In this case the products are said to be under thermodynamic control rather than kinetic control. A possible example has been given in the earlier description of the reaction of hydroxide ion with ester, when it seems likely that the products are the carboxylic acid and the alkoxide ion, which, however, are transformed in accordance with the relative acidities of carboxylic acids and alcohols into the isolated products of carboxylate salt and alcohol. 

The reaction of morpholine with 3-methylenebicyclo[2.2.1]heptan-2-one (98) gave the saturated ketone (99) as the only isolable product in 42% yield. 

In the case of enamines protonation on nitrogen or carbon is possible and gives the conjugate acids 4 and 5, respectively. Whereas the final isolated product has the iminium salt structure (5), recent work 10-12) has shown... 

Note that the final energy of the products in an IRC calculation may not equal tlie sum of the energies of the isolated molecules. An IRC terminates when the energy reaches a minimum for the molecular complex, a level which is slightly above the sum of the isolated product molecules. 

Sulfur bromides are but poorly characterized and there are few reliable data on them. SBr2 probably does not exist at room temperature but has been claimed as a matrix-isolated product when a mixture of S2Cl2/SCl2 Br2 Ar in the ratio 1 1 150 is passed through an 80-W microwave discharge and the product condensed on a Csl... 

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