4-bromo-2-ethyl

Preparation by Fries rearrangement of 4-bromo-2-ethyl-phenyl acetate with aluminium chloride without solvent in an oil bath (40%) [2907]. 

Bromo-2-ethyl-2-phenylglutarimide refluxed 2 hrs. with NaNg in methoxy-ethanol-water 2-amino-4-ethyl-4-phenylglutaconimide. Y 86%. G. Gasini, M. Felici, and M. Ferappi, Ann. Ghim. (Rome) 56, 1519 (1966) G. A. 66, 94788. 

Electrophilic attack on the sulfur atom of thiiranes by alkyl halides does not give thiiranium salts but rather products derived from attack of the halide ion on the intermediate cyclic salt (B-81MI50602). Treatment of a s-2,3-dimethylthiirane with methyl iodide yields cis-2-butene by two possible mechanisms (Scheme 31). A stereoselective isomerization of alkenes is accomplished by conversion to a thiirane of opposite stereochemistry followed by desulfurization by methyl iodide (75TL2709). Treatment of thiiranes with alkyl chlorides and bromides gives 2-chloro- or 2-bromo-ethyl sulfides (Scheme 32). Intramolecular alkylation of the sulfur atom of a thiirane may occur if the geometry is favorable the intermediate sulfonium ions are unstable to nucleophilic attack and rearrangement may occur (Scheme 33). 

Furan-3-carboxylic acid, 5-bromo-, ethyl ester H NMR, 4, 558 <71BSF990)... 

B-Butyraldehyde, condensation with N-phenylhydroxylamine, 46, 96 -Butyric acid, reaction with iron powder to yield 4-heptanone, 47, 75 Butyric acid, 7-bromo-, ethyl ester, 46, 42... 

Silver fluoborate, reaction with ethyl bromide in ether, 46, 114 Silver nitrate, complexing with phenyl-acetylene, 46, 40 Silver oxide, 46, 83 Silver thiocyanate, 45, 71 Sodium amide, in alkylation of ethyl phenylacetate w ith (2-bromo-ethyl)benzene, 47, 72 in condensation of 2,4-pentanedione and 1 bromobutane to give 2,4-nonanedione, 47, 92 Sodium 2 ammobenzenesulfinate, from reduction of 2 mtrobenzenesul-finic acid, 47, 5... 

Ethyl bromopyruvate Pyruvic acid, bromo-, ethyl ester (8) Propanoic acid, 3-bromo-2-oxo-, ethyl ester (9) (70-23-5)... 

Figure 2. Conversion versus time for substitution by tetrabutyl-ammonium benzoate on poly(epibromohydrin) (O) poly[(2-bromo-ethyl )oxirane] (0) poly[(3-bromopropyl )oxirane] (v, , separate runs) and poly [(4-bromo butyl )oxirane] (a, , separate runs).

STEREOSPECIFIC SYNTHESIS OF ETHYL (Z)-3-BROMO-2-PROPENOATE (2-Propenoic acid, 3-bromo-, ethyl ester, (Z)-)... 

More recent reports from Cordova [155] and Wang [156] have described the cyclopropanation of a, P-unsaturated aldehydes 99 with diethyl bromomalonates 100 and 2-bromo ethyl acetoacetate catalysed by a series of diaryIprolinol derivatives. Both describe 30 as being the most efficient catalyst in many cases and optimal reaction conditions are similar. Some representative examples of this cyclopropanation are shown in Scheme 40. The transformation results in the formation of two new C-C bonds, a new quaternary carbon centre and a densely functionalised product ripe for further synthetic manipulation. Triethylamine or 2,6-lutidine are required as a stoichiometric additive in order to remove the HBr produced during the reaction sequence. The use of sodium acetate (4.0 equivalents) as an additive led to subsequent stereoselective ring opening of the cyclopropane to give a,P-unsaturated aldehydes 101. It can be envisioned that these highly functionalised materials may prove useful substrates in a variety of imin-ium ion or metal catalysed transformations. 

Alkylation of intermediate with 2-(2-bromo-ethyl)thiophene affords the corresponding thiophene-... 

Fio. 35. Effect of therm pr quUibratk>n of the mobile phase. Chromatograms of identical samples of 3 bromo- -ethyl cinnamamide run at (A) 58 ml/h, (B) 115 ml/h, and (Q 230 ml/h on a 5>fim S tisoib 01 with unheated precolumn. Reprinted with permission from Itrchalski and wilder (176), Anal. Chem. Copyri t 1979 by the American Chemical Society. 

Automated parallel experiments were carried out to rapidly screen and optimize the reaction conditions for ATRP of methyl methacrylate (MMA) [34]. A set of 108 different reactions was designed for this purpose. Different initiators and different metal salts have been used, namely ethyl-2-bromo-tTo-butyrate (EBIB), methyl bromo propionate (MBP), (1-bromo ethyl) benzene (BEB), and p-toluene sulfonyl chloride (TsCl), and CuBr, CuCl, CuSCN, FeBr2, and FeCl2, respectively. 2,2 -Bipyridine and its derivatives were used as ligands. The overall reaction scheme and the structure of the used reagents are shown in Scheme 2. 

By the general procedure, 10.91 g (36.3 mmol) of (S (-pinanediol [(benzyloxy)methyl]boronatc is converted to (S)-pinanediol [(l.S)-2-(benzyloxy)-l-bromo-ethyl]boronate containing 6% unconverted [(benzyloxy)-methyljboronate. An analytical sample may be obtained by chromatography, but with considerable loss. 

Hg), nD 1.4269 at 20°. Prepd by reacting NaNO 2-bromo-ethyl-iso-valerate phloroglucinol in dimethylsulfoxide or dimethylformamide Refs 1) Beil, not found 2) N. Komblum et al, JACS 79, 2507-9(1957) CA 51, 13795 (1957)... 

Ethyl 2-bromohexanoate Hexanoic acid, 2-bromo-, ethyl ester. ( )- (10) (63927-44-6) Potassium fluoride (8,9) (7789-23-3)... 

Butanoic acid, 4-bromo-, ethyl ester, 67, 98 Butanoic acid, 4-iodo-, ethyl ester, 67, 98... 

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