Sodium iodide, substitution

The nitro groups need replacing by iodine atoms, and you should not be surprised that they were reduced to amino groups by hydrogenation over palladium and then diazotized. Sodium iodide substitutes I- for N 2-... 

Thus, to name just a few examples, a nucleophilic aliphatic substitution such as the reaction of the bromide 3.5 with sodium iodide (Figure 3-21a) can lead to a range of stereochemical products, from a l l mbrture of 3.6 and 3.7 (racemization) to only 3.7 (inversion) depending on the groups a, b, and c that are bonded to the central carbon atom. The ring closure of the 1,3-butadiene, 3.8, to cyclobutene... 

Methyl chloride can be converted iato methyl iodide or bromide by refluxing ia acetone solution ia the presence of sodium iodide or bromide. The reactivity of methyl chloride and other aUphatic chlorides ia substitution reactions can often be iacteased by usiag a small amount of sodium or potassium iodide as ia the formation of methyl aryl ethers. Methyl chloride and potassium phthalimide do not readily react to give /V-methy1phtha1imide unless potassium iodide is added. The reaction to form methylceUulose and the Williamson synthesis to give methyl ethers are cataly2ed by small quantities of sodium or potassium iodide. 

Benzenesulfenamide and a number of substituted benzenesulfenamides (compounds B, C, and D) have been prepared to protect the 7-amino group in cephalosporins. They are cleaved by sodium iodide (CH3OH, CH2CI2, AcOH, 0°, 20 min, 53% yield from sulfenamide B)."... 

Methylphenyl)benzothiazole (80IC762) and 2-benzylbenzothiazole (95ICA(239)125) can be cyclopalladated. In the latter case, cylopalladation occurs upon reaction with palladium(II) acetate and gives the product 80. With lithium chloride, sodium bromide, or sodium iodide, a series of three products of substitution of the acetate group 81 (X = C1, Br, I) results. Pyridine, 2- and 3-methylpyridine, 2,6- and 3,5-dimethylpyridine cause the transformation of the chelate complexes 81 (X = C1, Br, I) and formation of the mononuclear products 82 (R = z= R" = = R = H, X = Cl, Br, I ... 

The third double bond can be introduced into the oxepin system by the dehalogenation of appropriate bromine adducts of benzene oxides. 1-Substituted or 3-substituted 2,5-dibromo-7-oxabicyclo[4.1.0]hept-3-enes are converted with sodium iodide in acetone to mixtures of the respective oxepin 1 and benzene oxide 2.12150-156... 

The isomeric imidazo[l,5-a]pyrimidine (161) gave the 1,3-dibromo derivative when exposed to bromine or NBS (72BSF2481). Iodination of benzimidazo[2,l- >]quinazolin-12(5 or 6//)-ones was accomplished by boiling them with bromine in the presence of sodium or potassium iodide. Substitution took place at the 9-position in the benzimidazo moiety (91MI3). 

M aqueous solutions of iodopentaminecobalt(lll) decompose with first-order kinetics at 45 °C with = 6.0x 10" sec 10" M solutions decompose faster after an initial induction period at the normal rate. Product analysis shows the fast decomposition to be a mixture of a redox process leading to iodine and substitution leading to aquopentaminecobalt(iri) and iodide. Addition of sodium iodide (to 10 M) accelerates the decomposition and... 

Trimethylsilyl iodide can be substituted for the trimethylsilyl triflate catalyst in the reactions of aliphatic aldehydes. TMSI can be generated conveniently in situ either from trimethylsilyl chloride and sodium iodide in acetonitrile314 or from hexamethyldisilane and iodine in dichloromethane334 or pentane.338 It is noted that neither triisopropylsilane nor PMHS is an effective reducing agent for this purpose when used with TMSI under these conditions.314,334... 

The same research group also showed that the r-butyldimethylsilyl (TBDMS)-protected 4-substitued 4,5-dihydro-l,2,4-oxadiazol-5-one 192 afforded the alcohol 193 on treatment with ethanolic HC1. Mesylation and treatment of the intermediate with sodium iodide gave the iodofluoroalkenyl-substituted 4,5-dihydro-l,2,4-oxadiazol-5-one 194 (Scheme 26) <2004T10907>. 

In an extension of this work, the reuse of the polymeric catalyst was addressed and several new PE-poly(alkene) glycol copolymers were prepared [68]. Commercially available oxidized polyethylene (CO2H terminated, both high and low molecular weight) was converted to the acid chloride and reacted with Jeffamine D or Jeffamine EDR, and subsequently converted to the tributylammonium bromide salt with butyl bromide. These new quaternary salts were shown to catalyze the nucleophihc substitution of 1,6-dibromohexane with sodium cyanide or sodium iodide. While none of the polymeric quaternary salts catalyzed the reaction as well as tetrabutylammonium bromide, the temperature-dependent solubility of the polymers allowed removal of the polymer by simple filtration. 

Haloprogin Haloprogin, 3-iodo-2-propinyl-2,4,5-trichlorophenyl ether (35.4.11), is synthesized by an iodide substitution using a mixture of iodine and potassium iodide and a cupric derivative of 2,4,5-trichlorophenylpropargyl ether (35.4.10), which is synthesized by a standard method from propargyl bromide and 2,4,5-trichlorophenol in the presence of sodium hydroxide [65-67]. 

The generation and Diels Alder reaction of 4,5-bis(bromomethylene)-4,5-dihydrothiazole 39 has been investigated. 39 is a heterocyclic analogue of ortho-quinodimethanes and is generated by treating 4,5-bis(dibromomethyl)thiazole 38 with sodium iodide in dimethylformamide. 39 can be trapped in situ with symmetrical dienophiles to give substituted benzothiazoles such as 40 <98EJOC2047>. 

One of these consists in the substitution of iodine for the ester group attached to the primary carbon atom as the result of prolonged heating with sodium iodide in acetone solution (Finkelstein s reagent (20]). The reaction appears likely to consist in breaking the C—O linkage ... 

Com forth and co-workers914 employed zinc in a solution of sodium iodide and sodium acetate in acetic acid to effect reduction of several alkyl-substituted ethylene oxides to the corresponding olefins (Eq. 337). 

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