Reaction with 14-dibromopentan

The complex [Ni(TMC)]+ also reacts with disubstituted alkanes, X(CH2) Y (X, Y, = Cl, Br, I, OH, OTs) (n = 2-6) in aqueous solutions (144-146). With vicinal disubstituted alkanes (n = 2, 3), alkenes are formed quantitatively and the transient organonickel species is not detected. The reaction of [Ni(TMC)]+ with Br(CH2)3OH yields 1-propanol, but reactions with 1,3-disubstituted propanes (X, Y = Br, Cl, OTs) form cyclopropane exclusively. The reaction of 1,5-dibromopentane with excess Ni(I) complex results in cyclopentane. 

EtI the quaternary 1-ethyl-1-phenylphosphorinanium iodide, m.p. 188 °C, is formed (15CB1473). An excellent variant, again using 1,5-dibromopentane (or the very important l,5-dibromo-3-r-butylpentane) by reaction with tetraphenyldiphosphine, gives the 1,1-diphenylphosphorinanium bromides in 72% and 43% yield, respectively (equation 4) <63AG(E)620,77JOC1306). 

Likewise reactions with 1,3-dibromopropane, 1,4-dibromobutane, or 1,5-dibromopentane give the corresponding cyclobutyl-, cyclopentyl-, and cyclohexyl-1, 1 -dicarboxy lates. 

Dehuri and Nayak (83JIC970) reported that 3,4,5,6,7,8-hexahydro-l,3-diazocine-2-thione (213), obtained from 1,5-dibromopentane and thiourea in boiling ethanol, reacts with chloroacetic acid or its ethyl ester followed by basification to give 5//-6,7,8,9-tetrahydrothiazolo[3,2-a]-[ 1,3]diazocin-3(2//)-one (214). The reaction of 213 with ethyl chloroacetate was not smooth and the yield was low. The thione 213, on reaction with ethyl chloroacetate and aromatic aldehydes in the presence of pyridine and piperidine, furnishes the arylidene product 215 which is also obtained from 214 and aromatic aldehydes. No spectral data are cited to confirm the thiazolidinone structures 214 and 215 (Scheme 50). 

Bromo-5-phthalimido pentane is prepared by the interaction of 1, 4-dibromopentane with potassium phthalimide, which on reaction with 8-amino-6-methoxy quinoline yields the condensed product. Further treatment with hydrazine eliminates the phthalimido residue and yields the primaquine base which on reaction with a double molar quantity of phosphoric acid forms the official compoimd. 

Phenylphosphorinane, mp= 176°C, can be made by direct reaction of phenyl dilithiophosphine with dibromopentane in tetrahydrofuran, or by the action of UV radiation on (4-pentenyl)... 

Now let s draw the forward scheme. 1,1-Dibromopentane is converted to 1-pentyne by reaction with excess sodium amide (to afford double elimination followed by deprotonation of the resulting alkyne), followed by aqueous woikup to protonate the terminal aUcynide. 1-Pentyne is converted to the aldehyde via hydroboration/oxidation. Subsequent reaction with sodium acetylide, followed by aqueous woikup, produces an alcohol. Reduction with H2 and Lindlar s catalyst converts the alkyne group to an alkene group. Ozonolysis converts the alkene to an aldehyde. Reaction with concentrated acid allows for elimination of the alcohol, producing the target compound. 

This synthesis came shortly after one by Prelog, Kohlberg, Cerkovnikov, Rezek and Piantanida (1937) based on a series of reactions which, with modifications and extensions. Prelog and his colleagues have applied to the syntheses of bridged heterocyclic nuclei, of which this is an example. 4-Hydroxymethyltetrahydropyran (VI R =. OH) is converted via the bromo-compound (VI R = Br) and the nitrile (VI R = CN) into tetrahydropyran-4-acetic acid of which the ethyl ester (VII) is reduced to 4-()3-hydroxyethyl)-tetrahydropyTan (VIII). This is converted by fuming hydrobromic acid into 3-(2-bromoethyl)-l 5-dibromopentane (IX) which with ammonia in methyl alcohol yields quinuclidine (V). 

The higher solubility of several quaternary ammonium salts of glyphosate in polar aprotic organic solvents such as acetonitrile was discovered (2), which permitted their reaction in solution with various alkyl halides. For example, GLY(n-Bu4N)2H reacted with either o-xylylene dichloride or 1,5-dibromopentane to produce the interesting quaternary glyphosate derivatives 81 and 82, whose structures have been confirmed by x-ray analysis (2). 

For example, amine 140 was treated with 1,5-dibromopentane 141 to give the azoniaspirocycle 142 <1999RCB1696>. Carrying the reaction out under similar conditions with 1,2-dibromoethane gave the bis-addition species 143 as the major product rather than a spirocycle (Equation 32). There is always the need to pick reactants and conditions carefully to favor cyclization over k-addition. 

Total reduction of unbranched open-chain and cyclic derivatives of dichloro and dibromo alkanes occurs at room temperature within 30 minutes in dichloro-methane solutions containing ca. 2.5 equivalents of triethylsilane and ca. 0.25 equivalents of aluminum chloride.189 The reaction occurs equally well with geminal, vicinal, and m-dihalo alkanes. For example, 1,5-dibromopentane gives n-pen lane in 85% yield when treated in this way (Eq. 53).189... 

Alkylation of trifluoro- and trichloroacetamides with a-bromoacetic esters has been utilized for the synthesis of a wide range of a-aminoacetic acids [11-13] (Table 5.13). Hydrolysis of the intermediate a-trihaloacetamidoacetic esters with methanolic potassium hydroxide converts the methyl and ethyl esters directly into the amino carboxylic acids. /-Butyl a-aminoacetates are more stable, but they are hydrolysed under phase-transfer catalytic conditions (see Chapter 9.2). Reaction of the trihaloacetamides with 1,4-dibromobutane and 1,5-dibromopentane and subsequent hydrolysis provides a simple route to pyrrolidine-2-carboxylic acid (75%) and piperidine-2-carboxylic acid (58%) [11, 12],... 

The stereospecific C-alkylation of a range of benzylic ketones, such as tetralones, 2-phenylcyclohexanones and cycloheptanones, and 2-phenyl-y-lactones, has also been described [8]. For example, Af-(4-trifiuoromethylbenzyl)cinchonidinium bromide catalyses the reaction of 1,5-dibromopentane with 7-methoxy-l-methyl-2-tetralone to yield the (R)-l-(5-bromopentyl) derivative (75% yield with 60% ee). 

Pentamidine Pentamidine, 4-4 -(pentamethylendioxy)dibenzamidine (37.4.2), is made by reacting 4-hydroxybenzonitrile with 1,5-dibromopentane in the presence of sodium hydroxide to make l,5-few-(4-cyanophenoxy)pentane (37.4.1). Subsequent reaction of this with an ethanol solution of hydrogen chloride with the intermediate formation of an iminoester, and then with an ethanol solntion of ammonia gives the desired pentamidine [55-57]. 

Phenylpiperidine has been prepared by warming aniline with 1,5-dibromopentane 4,8 heating 5-anilino-l-bromopentane 6 the dehydration of 5-anilino-l-pentanol over alumina 7 the electrolytic reduction of N-phenylglutarimide 8 the catalytic hydrogenation of l-phenyl-3-hydroxypyridinium chloride 9 the action of bromobenzene on piperidine in the presence of lithium 10 the reaction of fluorobenzene, 1-methylpiperidine, and phenyl-lithium 11 the action of diphenylsulfone on piperidine in the presence of sodamide 12 the diazotization and deamination of l-(2-aminophenyl)piperidine 13 and of l-(4-aminophenyl)piperidine 14 and the present method.18... 

The reaction of aliphatic 1,5-Grignard compounds of 1,5-dibromopentane with dichlorophenylphosphine constituted the first synthesis of a phosphorinane derivative, 1-phenylphosphorinane (equation (3)). It is an air sensitive colourless oil with the characteristic strong smell of a phosphine. Addition of HgCl2 gives a solid product, m.p. 127 °C, With... 

When 1,5-dibromopentane was used, a small amount of 1,1-dibromo-1-telluracyclohexane was also formed as a by-product through, most probably, partial hydrolysis of Al2Te3 and the subsequent reaction of tellurium (from H2Te) with 1,5-dibromopentane. 

Nickelapentacycles have also been prepared by the reaction of 1,4-dihaloalkanes such as 1,4-dibromobutane or 1,4-dibromopentane with Ni(COD)(bipy) (bipy = 2,2 -bipyridyl) to afford complexes of type 71 as dark green crystalline... 

This chiral P-amino alcohol is obtained by reaction of (lS,2R)-norephedrine with 1,5-dibromopentane. 

Reaction of 1,5-dibromopentane with 4-phenyl- and 4-butyl-urazole has given rise to the novel 1,2-diazepine system (75).64... 

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