Phenethyl bromide

Condensation of the substituted phenethyl bromide, 18, with piperazine can be stopped at the monosubstituted amine (19). Reaction of this amine with propiophenone and formaldehyde in a Mannich reaction affords eprazinone (20) an antitussive agent. 

In the reaction of 88 with /(-phenethyl bromide, l-phenethyl-3-phenylpropyl methyl sulfoxide and bis-3-phenylpropyl sulfoxide, besides 3-phenylpropyl methyl sulfoxide are obtained118. Sulfoxides, bearing a /1-hydrogen to the sulfmyl function, give olefins upon thermolysis. Utilizing this reaction, Trost and Bridges120 alkylated benzyl phenyl sulfoxide, 3,4-methylenedioxybenzyl phenyl sulfoxide, phenylthiomethyl phenyl sulfoxide, phenylsulfinylmethyl phenyl sulfoxide and cyanomethyl phenyl sulfoxide with alkyl, allyl and benzyl halides and subjected these sulfoxides to thermolysis, obtaining olefins in one-pot processes. 

A very important microwave-specific effect was evidenced in the absence of a base for the reaction of pyrazole with phenethyl bromide (reaction times MW = 8 min, A = 48 h, Eq. 41). When the same reaction was performed in the presence of KOH, the microwave effect disappeared (vide supra, Eq. 26). 

Reaction of pyrazole with phenethyl bromide 84 Ring opening of an epoxide by amines 85... 

Phenacyl chloride, c31 Phenazone, a299 1,2,4-Phenenyl triacetate, tl 93 Phenethyl acetate, pill Phenethyl alcohol, pi 10 sec-Phenethyl alcohol, ml49 Phenethylamine, pi 12 Phenethyl bromide, b334 Phenethyl chloride, cl28 Phenetole, e36... 

Alkylation of pyrrolo-benzodiazepine dione 244 with methyl iodide occurs on both positions N9 and ClOa, while reaction with 2-bromo diethylaminoethane leads to the low yield of the 4-substituted 248. Acylations with benzoyl and 2-chloroacetyl chlorides are directed exclusively to position 4 to afford 247 (Scheme 52, Section 3.1.1.4 (1992CE649, 2005H2451)). Alkylation of 5H-benzo[/]-pyrrolo[l,2-d][l,4]diazepin-6(7H)-one with a substituted phenethyl bromide has been reported (Scheme 36, Section 3.1.1.1 (1992BMCL1639)). 

Alkylation of (17-5) with phenethyl bromide leads to phenazocine (18-1), a quite potent analgesic that, however, exhibits the same profile of side effects as the classical... 

Carbonylation of phenethyl bromide catalysed by Co2(CO)8 alone or modified either with tppts or tppms yielded products of double- and mono-carbonylation, (benzylpyruvic and benzylacetic acid, respectively) at a concentration of 8 mol% cobalt, 85°C and 20 bar CO under basic conditions in an H20/tBuOH (14/1) solvent mixture (Figure 13).475>476 The reaction rates exhibited by Co2(CO)8 were comparable with the Co2(CO)6(tppts)2 catalyst but replacement of tppts by tppms gave rise to a dramatic decrease in catalytic activity.475 Substantially different double/mono carbonylation (d/m ratios) were observed with Co2(CO)8, Co2(CO)e(tppts)2 and Co2(CO)6(tppms)2 7.3, 2.1 and 0.3, respectively, which... 

Figure 13 Double- and mono-carbonylation of phenethyl bromide.

Phenethyl bromide [103-63-9] M 185.1, b 92°/llmm, d 1.368, n 1.557. Washed with cone H2SO4, water, aq 10% Na2CO3 and water again, then dried with CaCl2 and fractionally distd just before use. Phenethyl urea [2158-04-5] M 164.2, m 173-174°. Crystd from water. 

Phenethyl bromide, b283 Phenethyl chloride, cl08 / -Phenetidine, e24 Phenetole, e28 Phenoxyacetone, p74 4-Phenoxybutyl bromide, b243... 

On the other hand, when the nucleophile reacts with the carbenium ion after it has separated from the leaving group, the reaction takes place with complete racemization. This is the case with more stable and consequently longer-hved carbenium ions. For example, the a-methyl benzyl cation, which is produced in the rate-determining step of the solvolysis of R-phenethyl bromide in a water/ethanol mixture, is such a cation (Figure 2.14). As in the solvolysis of Figure 2.13, the nucleophile is a water/ethanol mixture. 

Heptyl bromide was not hydrogenolyzed whatsoever, even in the presence of potassium acetate, while phenethyl bromide and 3-phenylpropyl bromide were hydo-genolyzed at considerable rates with addition of the base. Ethyl 3-bromopropionate, which resisted hydrogenolysis in neutral alcohol, as mentioned above, was hydrogenolyzed in the presence of the base, although at a slow rate. It is seen that the bomine located at the a-position is markedly activated by electron-withdrawing benzoyl and ethoxycarbonyl groups. 

Intramolecular cyclizations via aryl anions have been used to prepare benzocyclobutenes (138) from o-bromo-3-phenethyl bromides and benzocyclobutenols (139) from o-bromostyrene oxides. ... 

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