3- Pentyl iodide

The direction of elimination is also affected by steric effects, and if both the base and die reactant are highly branched, steric factors may lead to preferential removal of the less hindered hydrogen. Thus, when 4-methyl-2-pentyl iodide reacts with very hindered bases such as potassium tricyclohexylmethoxide, there is preferential formation of the... 

Another radical 1,4-addition was reported by Giese and Roth. In the photoaddition of a 5-alkylidene-l,3-dioxan-4-one with pentyl iodide, mediated by Bu3SnH and di-/r /t-butyl peroxide (DTBP), a 95 5 mixture of diastereoisomeric dioxanones was obtained in 63% yield (Equation 31) <1996JBS243>. 

To a flask containing 16.9 gm (0.26 mole) of sodium azide, 300 ml of Carbitol, and 50 ml of water is added all at once, with stirring, 39.6 gm (0.20 mole) of pentyl iodide. After a few minutes the homogeneous solution is heated to 95°C and kept there for 24 hr. After cooling to room temperature, the reaction mixture is poured into I liter of ice water. The organic layer is separated and the water layer is extracted with two 200 ml portions of ether. The ether and organic layers are combined, dried, and concentrated. The residue is distilled under reduced pressure to afford 18.9 gm (83.6%), b.p. 77°-78°C (112 mm), ng> 1.4266. 

Ylides (146) are cyclized by 30% aqueous hydrogen peroxide to afford the pyrido[ 1,2- ] azepines (147) (91HCA1095). The pyridof 1,2- ]azepinium system (148) is also obtainable by intramolecular free radical cyclization of 5-(l-pyridinio)-pentyl iodide (91T4077). 

Pentendial, AE31 Pentylamine, AF03 Pentyl bromide, AE82 Pentyl iodide, AE85... 

Monomethinecaynine Dyes The oldest dye of the this series is cyanine, a blue dye after which the whole class of dyes was named. Cyanine (42) was synthesized by Williams in 1856 from crude tar quinoline by quatemization with pentyl iodide, followed by treatment with alkali. The unsymmetrical monomethine dye coupled in the 2- and 4-positions of quinoline is termed isocyanine. 

Methyl-butyl- -iodid XIII/2a, 635 Pentyl- -iodid XIII/2a, 638... 

The same hexane, however, may also be prepared from pentyl iodide and methyl iodide with sodium so that it may be represented as containing the two radicals normal pentyl and methyl, and could be called pentyl methane,... 

Least et al. reduced the sample size to 20 pi serum, plasma, or saliva, in a microscale procedure. The extraction was carried out with a chloroform-isopropanol solution of the internal standard, 3-isobutyl-l-methylxanthine. After alkylation with tetramethylammonium hydroxide and pentyl iodide, gas chromatography was carried out on a packed 3 OV-17 on Gas Chrom Q column, by temperature programming from 180°C to 260°C, and using a nitrogen sensitive detector. With the sample volume used, the background interference is equivalent to about 0.1 mg/litre, and 0.5 mg theophylline per litre can easily be measured. Between-run... 

Direct preparation of an alkyl iodide by reaction (a) neopentyl iodide, (CH3)3CCH2I 957,958 Methyl iodide (1.4 moles), triphenyl phosphite (1 mole), and neopentyl alcohol (1 mole) are heated in a bath for 24 h, whereby, owing to continuing consumption of methyl iodide, the internal temperature rises from 75° to 130°. The crude iodide and the phenol are distilled off in a vacuum and the distillate is washed with ice-cold, dilute NaOH solution, and water until free from phenol. The product contains about 6% of te/7-pentyl iodide,958 to remove which it is shaken for 5 h with three times its volume of water which is then discarded. The organic layer is next shaken with its own volume of O.lN-aqueous AgN03, washed with water, dried, and fractionated. This gives a 53-57% yield of iodide of b.p. 71°/100 mm. 

Pentyl azide 662 A mixture of activated sodium azide663 (27 g), diethylene glycol monoethyl ether ( Carbitol ) (450 ml), and water (75 ml) is placed in a 1-1 three-necked flask fitted with a reflux condenser, thermometer, and stirrer the mixture is stirred while pure pentyl iodide (60 g) is added in one portion. The solid dissolves within a few minutes. Whilst being continuously stirred, the mixture is heated during 3 h to 95° and then kept at that temperature for 20 h. It is then cooled and poured in two portions into separate portions of ice-water (each 800 ml). The aqueous phases are separated and extracted twice with ether (200-ml batches). The ether solutions are united with the previous organic phases, and the ether is evaporated. The residue (42 g) is fractionated in a vacuum, giving the azide, b.p. 77-78°/112 mm, nD20 1.4266 (27.8 g, 81.4%). 

At the same time, a second aliquot was quenched with pentyl iodide. A dipentyldihydroperylene (MS molecular ion at m/z = 394, I = 1.4 pentyl-loss ion at m/z = 323, I = 54 and second pentyl-loss ion at m/z = 252, I = 100) was the predominant perylene-containing species it was 32 times more abundant than the recovered perylene. 

Thus, the radical anion of naphthalene reacted differently with methyl iodide (to form methyl radicals) than with pentyl iodide (to undergo substitution). Perylene, on the other hand, underwent substitution with methyl iodide whether or not naphthalene was present perylene also underwent substitution with pentyl iodide when naphthalene was present. 

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