3- bromo-2- 1- methoxy

The nature of the solvent also determines the chemoselective outcome in the reaction products. Products arising from the incorporation of one solvent molecule are formed (besides dibromides) in alcohols, acetic acid and acetonitrile (Id-e), whereas dibromo derivatives are formed exclusively in chlorinated solvents, nitromethane and in ionic liquids. (9) Chemoselectivity depends on the relative nucleophilicity of the solvent and the counterion, although it is affected also by other phenomena (ion pairing, and ion dissociation) in methanol the addition process gives quasi-exclusively bromo-methoxy adducts, whereas in acetic acid dibromides are the main products, formed in addition to smaller amounts of the bromo-acetoxy derivatives. (70)... 

Such reactions have also been carried out on benzofurans carrying benzyl, fluoro, chloro, bromo, methoxy, cyano, and phenyl groups in the benzo ring. Substitution in the stilbene part of the molecule can also be obtained by the use of Schiff s bases derived from differing benzal-dehydes.26,28,29... 

Acetylindole and methyl iodide at 150°C for 15 hr gave the unstable 5-acetylFischer s base, which upon immediate reaction with the appropriate salicy-laldehyde was converted to 5 -acetyl-6-nitroBIPS and its derivatives containing bromo, methoxy, and nitro groups in the 8-position. Compared with the corresponding compounds without the acetyl substituent, the positions of the absorption... 

D Cruz, O. I, and Uckun, F. M. (2001), Lack of adverse effects on fertility of female CD-I mice exposed to repetitive intravaginal gel-microemulsion formulation of a dualfunction anti-HIV agent Aryl phosphate derivative of bromo-methoxy-zidovudine (compound WHI-07), J. Appl. Toxicol., 21,317-322. 

D cruz, O. Venkatachalam, T. Uckun, F. Structural requirements for potent human spermicidal activity of dual function aryl phosphate derivative of bromo-methoxy zidovudine. Biol Reprod 2000, 62, 37-44. 

Substituents exert pronounced effects on the absorption spectra. In general, meta- and /tara-substituted phenoxyl radicals exhibit absorption maxima at higher wavelengths than the ortho analogues. On the other hand, the /tara-substituted phenoxyl radicals have extinction coefficients considerably higher than those of either the ortho or the meta analogues. These general trends hold for the methyl-, bromo-, methoxy- and hydroxyphenoxyl radicals, and for the semiquinones. 

Best results were obtained when the active manganese was added to the neat benzyl bromide. The reaction was completed within 10 min at rt without a catalyst [39]. Several other benzyl halides produced good to excellent yields of homocoupling products, which showed a wide tolerance of functional groups such as nitrile, ester, nitro, chloro, bromo, methoxy, and methyl groups (Table 8.16). 

III-G 8. Bromo(methoxy)methane (Bromomethyl Methyl Ether, CH30CH2Br)... 

Alkoxyall l Hydroperoxides. These compounds (1, X = OR , R = H) have been prepared by the ozonization of certain unsaturated compounds in alcohol solvents (10,125,126). 2-Methoxy-2-hydroperoxypropane [10027-74 ] (1, X = OR , R" = methyl), has been generated in methanol solution and spectral data obtained (127). A rapid exothermic decomposition upon concentration of this peroxide in a methylene chloride—methanol solution at 0°C has been reported (128). 2-Bromo-l-methoxy-l-methylethylhydroperoxide [98821-14-8]has been distilled (bp 60°C (bath temp.), 0.013 kPa) (129). Two cycHc alkoxyaLkyl hydroperoxides from cyclodecanone have been reported (1, where X = OR R, R = 5-oxo-l, 9-nonanediyl) with mp 94—95°C (R" = methyl) and mp 66—68°C (R" = ethyl) (130). Like other hydroperoxides, alkoxyaLkyl hydroperoxides can be acylated or alkylated (130,131). 

Photocycloaddition. Synthesis of the highly carcinogenic polycycHc hydrocarbons, eg (51) [72735-91-2] may be affected by photocycloaddition of 2-bromo-3-methoxy naphthoquinone [26037-61-6] with 1,1-diarylethylenes such as l,l-bis(p-methoxyphenyl)ethene (41). 

Nucleophilic Substitution Reactions. Many of the transformations reali2ed through Michael additions to quiaones can also be achieved usiag nucleophilic substitution chemistry. In some iastances the stereoselectivity can be markedly improved ia this fashion (100), eg, ia the reaction of ben2enethiol with esters (R = CH C O) and ethers (R = 3) 1,4-naphthoquiaones. 2-Bromo-5-acetyloxy-l,4-naphthoquiQone [77189-69-6J, R = Br, yields 75% of 2-thiophenyl-5-acetyloxy-l,4-naphthoquinone [71700-93-1], R = SC H. 3-Bromo-5-methoxy-1,4-naphthoquinone [69833-10-9], R = Br, yields 82% of 3-thiophenyl-5-methoxy-l,4-naphthoquinone [112740-62-2] R = SC H. ... 

When large groups, such as phenyl, bromo, ethoxycarbonyl or nitro are attached at position 3, the principal products are l-alkylcinnolin-4(l/f)-ones. Cyanoethylation and acetylation of cinnolin-4(l/f)-one takes place exclusively at N-1. Phthalazin-l(2/f)-ones give 2-substituted derivatives on alkylation and acylation. Alkylation of 4-hydroxyphthala2in-l(2/f)-one with an equimolar amount of primary halide in the presence of a base leads to 2-alkyl-4-hydroxyphthalazin-l(2/f)-one and further alkylation results in the formation of 4-alkoxy-2-alkylphthalazinone. Methylation of 4-hydroxy-2-methyl-phthalazinone with dimethyl sulfate in aqueous alkali gives a mixture of 4-methoxy-2-methylphthalazin-l(2/f)-one and 2,3-dimethylphthalazine-l,4(2//,3//)-dione, whereas methylation of 4-methoxyphthalazin-l(2/f)-one under similar conditions affords only 4-methoxy-2-methylphthalazinone. 

Addition of bromine to 5-f-butyl-3,6-dimethoxy-4,5-dihydropyridazine produces 5-bromo-4-f-butyl-3-methoxy-4,5-dihydropyridazin-6(l//)-one. 

Methylthiophene is metallated in the 5-position whereas 3-methoxy-, 3-methylthio-, 3-carboxy- and 3-bromo-thiophenes are metallated in the 2-position (80TL5051). Lithiation of tricarbonyl(i7 -N-protected indole)chromium complexes occurs initially at C-2. If this position is trimethylsilylated, subsequent lithiation is at C-7 with minor amounts at C-4 (81CC1260). Tricarbonyl(Tj -l-triisopropylsilylindole)chromium(0) is selectively lithiated at C-4 by n-butyllithium-TMEDA. This offers an attractive intermediate for the preparation of 4-substituted indoles by reaction with electrophiles and deprotection by irradiation (82CC467). 

Bromination of 1,2-benzisoxazoles gave primarily the 5-bromo derivative, although other isomers have also been reported (67AHC(8)277). Bromination of 5-methoxy-3-methyl-l,2-benzisoxazole at room temperature gave a mixture of the 4- and 6-bromo compounds, while at elevated temperatures a 4,6-dibromo compound was produced (Scheme 27) <79IJC(B)371). 

---