Sodium iodide, in conversion

Sodium cyclopentadienide, 41, 96 Sodium dichromate for oxidation of alkylarcncs to aromatic carboxylic acids, 43, 80 Sodium iodide, in conversion of 2,4-di-nitrochlorobenzene to 2,4-dinitro-iodobenzene, 40, 34 reduction of peroxide with, 41,... 

One of the most used resins in solid-phase combinatorial organic synthesis, which has found a myriad of applications, is the Merrifield resin (17).61 This resin is also the building block for a tremendous amount of novel resins being developed in combinatorial chemistry with applications in both solid-phase as well as solid-phase-assisted solution-phase combinatorial chemistry. A recent, useful, and novel example is the report of its being employed as a triphenylphosphine scavenging resin.76 During the conversion of azidomethylbenzene (51) into benzylamine, excess triphenyl-phosphine is allowed to react with Merrifield resin (17) in the presence of sodium iodide in acetone. A phosphonium-substituted resin (52) is thus formed. Upon simple filtration, pure benzylamine is isolated as shown in Fig. 22. 

Treatment of the monoethylidene-D-mannitol with lead tetraacetate or periodate resulted in the consumption of two molecular equivalents of oxidant with the concomitant production of one mole of formaldehyde, one mole of formic acid and a monoethylidene-D-erythrose, the latter being identified by its conversion into the known crystalline D-erythrosazone.118 This evidence limited the choice of structure for the mannitol acetal to the 1,3- and 2,3-compound (4,6- and 4,5- are the respective identical structures). Two additional facts eliminated the latter alternative, first, the tetratosyl ester gave only one mole of sodium p-toluenesulfonate when heated with sodium iodide in acetone, and secondly, the same monoethylidene-D-mannitol was obtained from the above 1,3,4,6-diethylidene-D-mannitol by acidic hydrolysis.118 For these reasons Bourne, Bruce and Wiggins118 assigned to the mono-, di- and tri-ethylidene-D-mannitols, respectively, the 1,3-, 1,3 4,6- and 1,3 2,5 4,6- structures. 

The Finkelstein procedure169 exploits the solubility differences between halide salts (e.g. Nal and NaCl in acetone170) to effect the conversion of alkyl chlorides to alkyl iodides. Ferric chloride has been used as catalyst in Finkelstein reaction of tertiary alkyl and benzyl chlorides and sodium iodide in nonpolar solvents171. Cu(I) iodide, combined with potassium iodide in HMPA, is used for the synthesis of gem-diiodoolefins from the corresponding gem-dibromides172. 

Conversion into Pyrazine Derivatives. Pyrazine derivatives are examples of 1,2-diazines in the carbohydrate series (24), The derivative was prepared by partial tosylation of 41 to give the mono-p-toluene-sulfonyl derivative (60), which upon treatment with sodium iodide in acetone gave the bicyclic diazine derivative (62). However, the di-p-toluenesulfonyl derivative (61) afforded, under conditions similar to those specified, the 6-deoxy-6-iodo 63. The 6-bromodeoxy 64 was prepared (54) by reacting phenylhydrazine with 6-bromo-6-deoxy-L-ascorbic acid. 

Halide exchange from the lower halides to iodine is often desirable due to the higher reactivity of iodides in nucleophilic substitutions, reductions, organometallic or radical reactions (Scheme 30). Conversion of chlorides and bromides to iodides with sodium iodide in acetone is called the Finkelstein reaction. This halide exchange is an equilibrium process, which is shifted to the iodinated products due to precipitation of the less soluble sodium bromide or chloride from acetone. Best results are obtained when the reaction mixture is free of water. 

Another versatile pathway to acid iodides was described by Hoffmann (equation 13). Aliphatic and aromatic acid iodides are prepared in high yields from acid chlorides by reaction with sodium iodide in acetonitrile. A large number of alkanoyl, alkenoyl and aroyl iodides can be prepared in good yields from the corresponding acid chlorides. In the same way it was possible for the first time to obtain diiodides from aliphatic and aromatic dicarboxylic acids. The conversion of acid chlorides to iodides by sodium iodide had been known before the reaction conditions proposed by Hoffmann, however, are milder and the yields are higher. 

The same year, Gerlach described a synthesis of optically active 1 from (/ )- ,3-butanediol (7) (Scheme 1.2). The diastereomeric esters produced from (-) camphorsulfonyl chloride and racemic 1,3-butanediol were fractionally recrystallized and then hydrolized to afford enantiomerically pure 7. Tosylation of the primary alcohol, displacement with sodium iodide, and conversion to the phosphonium salt 8 proceeded in 58% yield. Methyl-8-oxo-octanoate (10), the ozonolysis product of the enol ether of cyclooctanone (9), was subjected to Wittig condensation with the dilithio anion of 8 to give 11 as a mixture of olefin isomers in 32% yield. The ratio, initially 68 32 (E-.Z), was easily enriched further to 83 17 (E Z) by photolysis in the presence of diphenyl disulfide. The synthesis was then completed by hydrolysis of the ester to the seco acid, conversion to the 2-thiopyridyl ester, and silver-mediated ring closure to afford 1 (70%). Gerlach s synthesis, while producing the optically active natural product, still did not address the problem posed by the olefin geometry. 

A useful method for the conversion of quinoline-2- and -4- and isoquinoline-1-chlorides into iodides utilizes the hydrochloride salt of the heterocycle in reaction with sodium iodide in hot acetonitrile presumably it is the A-protonated species that is attacked by the iodide. ... 

The chloride (62) thus obtained was resistant to subsequent hydrolysis to the alcohol (47). Therefore, (62) was quantitatively converted into (64) by treatment with sodium iodide in ethyl acetate. For replacement of the iodine in (64) with a hydroxy group, various methods were investigated. These included use of silver perchlorate in aqueous acetone, treatment with silver nitrate or a combination of sodium nitrate and methyl p-toluenesulfonate followed by reduction of the allylic nitrate intermediate with zinc and acetic acid, and application of the Evans method involving sulfoxide rearrangement [29]. A conversion method... 

New reagents for the primary and secondary alcohol to alkyl iodide conversion, with inversion at secondary centres, are diphosphorus tetraiodide (P2I4), a well characterized and stable solid, and mixtures of triphenylphosphine with iodine and imidazole or with 2,4,5-tri-iodoimidazole. The P2I4 system also iodinates tertiary alcohols. Trimethylsilyl iodide is known to convert alcohols into iodides (2,128), and some more systems that are believed to generate trimethylsilyl iodide in situ have been found to effect the alcohol to iodide conversion (c/. 3,151). Trimethylsilyl chloride-sodium iodide in acetonitrile produces iodides from alcohols direct or from their trimethylsilyl ethers. Hexamethyldisilane-... 

Similarly, the transformation of alcohols to nitriles is a much sought after transformation, and a new procedure now allows the direct one-step conversion by the use of sodium cyanide-trimethylsilyl chloride and a catalytic amount of sodium iodide in dimethylformamide-acetonitrile. 

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