Naphthalene 2-bromomethyl

Bromomethyl)-2 methylbenzene 1-(Bromomethyl)-3-methylbenzene 1-(Bromomethyl)-4-methylbenzene 1-(Bromomethyl)naphthalene 2-(Bromomethyl)naphthalene... 

Bromomethyl)-naphthalene [939-26-4] M 221.1, m 52-54°, 56°, 56-57°, b 133-136°/0.8mm, 214°/100mm. Dissolve in toluene, wash with saturated aqueous NaHC03, dry (Mg SO4), evaporate and fractionally distil the residue and recrystallise the distillate from EtOH. [J Chem Soc 5044, 1952 Bull Soc Chim Fr 566 7955.]... 

The method illustrates the ability of the sodium hydride-dimethylformamide system to effect the alkylation of aromatic sulfonamides under mild conditions and in good yield. The method appears to be fairly general. The submitters have prepared N,N-diethyl- and N,N-di- -butyl- >-toluenesulfonamide as well as 2-(/ -tolyIsuIfonyl)benz[/]isoindoline from 2,3-bis-(bromomethyl)naphthalene, and 1 %-tolylsulfony])pyrrolidine from 1,4-dichIorobutane the yield of purified product exceeded 75% in each case. 

Dissolve 71 g. of P-methylnaphthalene in 460 g. (283 ml.) of A.B. carbon tetrachloride and place the solution in a 1 -litre three-necked flask equipped with a mechanical stirrer and reflux condenser. Introduce 89 g. of JV-bromosuccinimide through the third neck, close the latter with a stopper, and reflux the mixture with stirring for 16 hours. Filter ofiT the succinimide and remove the solvent under reduced pressure on a water bath. Dissolve the residual brown oil (largely 2-bromomethyl naphthalene) in 300 ml. of A.R. chloroform, and add it to a rapidly stirred solution of 84 g. of hexamine in 150 ml. of A.R. chloroform contained in a 2-litre three-necked flask, fitted with a reflux condenser, mechanical stirrer and dropping funnel maintain the rate of addition so that the mixture refluxes vigorously. A white solid separates almost immediately. Heat the mixture to reflux for 30 minutes, cool and filter. Wash the crystalline hexaminium bromide with two 100 ml. portions of light petroleum, b.p. 40-60°, and dry the yield of solid, m.p. 175-176°, is 147 g. Reflux the hexaminium salt for 2 hours with 760 ml. of 60 per cent, acetic acid, add 160 ml. of concentrated hydrochloric acid, continue the refluxing for 5 minutes more, and cool. Extract the aldehyde from the solution with ether, evaporate the ether, and recrystallise the residue from hot -hexane. The yield of p-naphthaldehyde, m.p. 69-60°, is 60 g. 

As an extension of their work on the [4+ 4]-reaction of zirconacyclopentadienes and l,2-bis(bromomethyl)arenes (Section 10.13.2.4), Takahashi and co-workers reported a [5 + 4]-reaction based on the use of l,8-bis(bromomethyl)-naphthalene as the five-carbon component.85 As with the [4 + 4]-reaction, the [5 +4]-reaction works with a catalytic amount of CuCl, but higher yields and faster reactions result when stoichiometric CuCl and 1,3-dimethyl-3,4,5,6-tetrahydro-2(l//)-pyrimidinone(iV,iV -dimethylpropyleneurea) (DMPLJ) are used (Scheme 42). 

The difference in the reactivity of benzylic versus aromatic halogens makes it possible to reduce the former ones preferentially. Lithium aluminum hydride replaced only the benzylic bromine by hydrogen in 2-bromomethyl-3-chloro-naphthalene (yield 75%) [540]. Sodium borohydride in diglyme reduces, as a rule, benzylic halides but not aromatic halides (except for some iodo derivatives) [505, 541]. Lithium aluminum hydride hydrogenolyzes benzyl halides and aryl bromides and iodides. Aryl chlorides and especially fluorides are quite resistant [540,542], However, in polyfluorinated aromatics, because of the very low electron density of the ring, even fluorine was replaced by hydrogen using lithium aluminum hydride [543]. 

Figure 9-6 Bond lengths, angles, and arrangement of carbons and bromines in a crystal of 1,8-bis(bromomethyl)naphthalene, 1, as determined by x-ray diffraction. Notice that the preferred conformation in the crystal has the bromines on opposite sides of the naphthalene ring.

The reaction has been extended to a,a-dichloro-o-xylene [78JOM(146)245] and 2,3-bis(bromomethyl)quinoxaline [84JCS(D)23]. In both cases the addition of Nal was found to facilitate the cycliza-tion reaction. With l,8-bis(bromomethyl)naphthalene, l,l-diiodo-3,5-naphtho-1-telluracyclohexane 7 has been obtained by the reaction with Te and Nal in 2-methoxyethanol [88JOM(338)l]. 

Bromo-2-(bromomethyl)naphthalene (l-Bromo-2-naphthyl)methanol... 

Similar transient behavior—formation of the charge transfer complex— was observed following irradiation of the radical derived from l-bromo-(2-bromomethyl)naphthalene, i.e., the l-bromo-2-naphthylmethyl radical (158) [99]. However, product evidence was ambiguous with respect to the production of the 1,3-biradical intermediate (Scheme 10). 

Indoles can be 3-alkylated by allyl alcohols in the presence of lithium perchlorate and acetic acid 101 is an example (Scheme 42). Pyrrole -alkylation can be achieved with simple alkyl halides [1-bromopentadecane, l-(bromomethyl)-, l-(3-chloropropyl)- and l-(3-iodopropyl)benzenes, 2-(2-bromoethyl)- and 2-(3-bromopropyl)naphthalenes] and mesylates [3-phenylpropyl-, l-methyl-3-phenylpropyl-, 2-(2-naphthyl)ethyl- and 3-(2-naphthyl)propyl methanesulfonates] selectively at C(2) and C(5) positions via reaction in various ionic liquids (e.g., Scheme 43) <20050L1231>. 

The crown ether-catalyzed generation of the Co( CO)4 ion in ether or hydrocarbon solvents has been described (32). Treatment of the anion with 2,3-bis(bromomethyl)naphthalene in tetrahydrofuran gives what is formulated as a bis-7r-allyl complex, while ketones were isolated using monocyclic dibromides as substrates. 

Similar reaction of tris(SES) triamines (diethylenetriamine and dipropylenetriamine) with a series of bis(bromo-methyl)arenes (naphthalene, anthracene) afforded arene-containing macrocycles in high yields <2001JOC2722>. Alternatively, o-nitrobenzenesulfonyl (nosyl, Ns) <2001BML1521> or nosyl/trifluoroacetyl <20010L3499> derivatives of ethylene-propylenetriamine and dipropylenetriamine were cyclized with methyl 3,5-bis(bromomethyl)benzoate... 

By using l,8-bis(bromomethyl)naphthalene, naphtho[2,1-6 7,8-6 ]-diquinolizinediium salt (220) was obtained (90%) (68JHC253). 

The NSEC group can be introduced under standard conditions using NSECCl which is available in three steps from chlorodimethylvinylsilane and 2-(bromomethyl)naphthalene (O Scheme 49). The NSEC group may be difficult to introduce in sterically demanding positions. 

An application of the nickel catalysis is shown here in the formation of 2,7-disubstituted derivatives of naphthalene, which are less common in the library of commercial fine chemicals. For these reasons, the submitters developed some synthetic routes to 2,7-bis(diethylcarbamoyloxy)naphthalene, 2,7-dimethylnaphthalene4 and 2,7bis(bromomethyl)naphthalene that will facilitate access to a large family of 2,7-disubstituted naphthalenes.5 The low cost of N,N-diethylcarbamoyl chloride, relative to triflic anhydride (for making aryl triflates), allows... 

Scheme 1. A Few Synthetic Uses of 2,7-Dimethylnaphthalene and 2,7-Bis(bromomethyl)naphthalene... 

The reaction between 1,8-bis(bromomethyl)naphthalene and Ph2PSiMe2 affords a cyclic phosphonium salt (1), which can be rearranged with Me2P=CH2 to give the cyclic ylide (2). 

---