Ethyl bromide synthesis

Thus, the condensation product of cyclohexanone and ethyl cyanoacetate (125) affords the intermediate (126) for the synthesis of cyclobarbital (112) on alkylation with ethyl bromide. The condensation product of cycloheptanone (127) affords the starting... 

An alternative source of the ethyl component was ethyl bromide, a less expensive material. It was at this point that GM called upon DuPont to take over process development. DuPont was the largest U.S. chemical company at the time. It had extensive experience in the scale-up of complex chemical operations, including explosives and high-pressure synthesis. The manufacturing process was undertaken by DuPont s premier department, the Organic Chemical section. GM contracted with DuPont to build a 1,300 pound per day plant. The first commercial quantities of TEL were sold in Februai-y 1923 in the form of ethyl premium gasoline. 

Ethylbenzene plants, 23 330-331 Ethylbenzene-styrene complex, 23 328 Ethylbenzene synthesis molecular sieves in, 16 845 zeolite-based alkylation in, 23 331-333 Ethyl benzoate, 3 635 Ethyl P-D-glucopyranoside, 4 701 7-Ethylbicyclooxazolidine, antimicrobial used in cosmetics, 7 831t Ethyl bromide, physical properties of, 4 351t... 

Sonawane et al. (Sonawane et al., 1994) described a practical and efficient synthesis of fenoprofen using commercially available m-phenoxybenzaldehyde as the starting material. The key step in the synthesis is the transformation of the a-hydroxyacetal (i) into its chlorosulfonyl ester in situ and its concomitant rearrangement to the methyl ester (ii) in high yields. The required a-hydroxyacetal (i) can be readily prepared from m-methoxybenzaldehyde by the routine sequence of reactions Grignard reaction with ethyl bromide or chloride, oxidation and finally a-chlorination with CuCI2-LiCI/DMF. 

Synthesis of ethyl bromide from hydrogen bromide and ethylene, using G -radiation from cobalt-60. 

SYNTHESIS A solution of 13.3 g 3,4-diethoxyphenol (see the recipe for MEE for its preparation) in 20 mL MeOH, and a solution of 4.8 g KOH in 100 mL hot MeOH were combined. There was added 8.2 g ethyl bromide and the mixture was held at reflux on the steam bath for 2 h. The reaction was quenched by the addition of three volumes H20, made strongly basic by the addition of 10% NaOH, and extracted with... 

SYNTHESIS To a solution of 12.3 g 3-ethoxy-4-methoxyphenol (see recipe for MEM for the preparation of this phenol) in 20 mL MeOH, there was added a warm solution of4.8gKOH in 100 mL MeOH. There was then added 8.2 g ethyl bromide, and the mixture held at reflux on the steam bath. Within 0.5 h, severe bumping ensued. An additional 3 g ethyl bromide were added, refluxing continued for... 

SYNTHESIS To a solution of 14.0 g 4-ethoxy-3-methoxyphenol (see the recipe for MME for the preparation of this starting material) in an equal volume of EtOH, there was added a solution of 5.3 g KOH in 100 mL hot MeOH. This was followed with 9.1 g ethyl bromide, and the mixture was held at reflux for 2 h. The first deposition of KBr was apparent in 5 min, and there was rather severe bumping by the end of the reaction. The mixture was diluted with 3 volumes H20 and 1 volume 5% NaOH, and extracted with 2x200 mL Et20. The extracts were pooled, and the solvent removed under vacuum, yielding 14.3 g of a pale amber oil that set to crystals of 2,5-diethoxyanisole with a mp of 44-45 °C. The compound had been reported in the literature from the action of diethyl sulfate on methoxyhydroquinone. 

SYNTHESIS To a solution of 166 g bourbonal in I L MeOH there was added a solution of 66 g KOH pellets in 300 mL H,0. There was then added 120 g ethyl bromide, and the mixture was held at reflux on the steam bath for 3 h. The reaction was quenched with three volumes of H20, and made strongly basic by the addition of 25% NaOH. This was extracted with 3x300 mL CH.C1, and the pooled extracts stripped of solvent under vacuum. There remained 155 g of 3,4-diethoxybenz-aldehyde as a fluid oil that had an infra-red spectrum identical (except for being slightly wet) to that of a commercial sample from the Eastman Kodak Company. 

Reaction of the anion of 1-butyne with ethyl bromide completes the synthesis. 

Two of these methods, the Gabriel synthesis and the preparation and reduction of the corresponding azide, begin with ethyl bromide. 

This reaction has been applied both to synthesis and as a mechanistic criterion for the intermediacy of anions, e.g., in the reduction of carbonyl compounds in aprotic solvents. Electrolysis of benzophenone in the presence of ethyl bromide yields diphenylethylcarbinol (41, Eq. (106) ) 2511. When anthraquinone... 

Raw stock is sent to the apparatus in tanks 1 installed in the drafting device (one is shown in the figure). Then it is sent by nitrogen flow to the batch boxes trifluoromonochloropropane to batch box 2, trichlorosilane to batch box 3, ethyl bromide to batch box 4, and dibutyl ether (dehydrated with burnt calcium chloride and filtered) to batch box 5. Before the synthesis begins, working mixtures I and II are prepared in apparatus 6. Mixture I consists of trichlorosilane and ethyl bromide, and mixture II consists of trichlorosilane, dibutyl ether, trifluoromonochloropropane and ethyl bromide. Mixture I is sent to batch box 8, and mixture II is sent to batch box 9. All batch boxes and apparatus 6 have jackets or coils (on their external walls) to be cooled with Freon at -15 - -20°C. 

To prepare the reactive mixture, agitator 1 is filled with a necessary amount of chlorobenzene and tetraethoxysilane (the content of the main substance is 97%). Then ethyl bromide is added to activate the synthesis. The reactive mixture is agitated for 30-60 minutes, sampled (to determine the chlorobenzene and tetraethoxysilane ratio) and pumped into weight batch box 5. After that, reactor 7 is loaded through a hatch with magnesium chipping and with part of the reactive mixture from weight batch box... 

Reactor 3 with a shielded electric drive agitator, which has been dried with nitrogen, is loaded with a necessary amount of aluminum powder, petrol and 50-60% petrol solution of triethylaluminum sesquichloride. The agitator is switched on, the mixture is heated to 50-60 °C aluminum is activated by adding ethyl bromide gradually and at constant temperature. The heated reactor is filled with ethylchloride at such speed that the given temperature is maintained. After ethylchloride has been supplied, the mixture is held at reaction temperature for 1-2 hours to complete the synthesis. The obtained product is cooled and loaded off into collector 7. 

The production diagram of diethyl tin dicaprylate is given in Fig. 93. Before synthesis the whole system is washed, dried and pressurised with nitrogen (the pressure is 0.05 MPa). After that reactor 1 is loaded through a hatch with magnesium and several grams of crystalline iodine (the initiator of the reaction), the agitator is switched on and inverse cooler 4 is filled with water. Then the reactor is filled at room temperature with part of the reactive mixture (ethyl bromide, diethyl ether and benzene) from batch box 2 to stimulate the reaction. 

The reaction of hexaethyldigermane and potassium in ethylamine solution led Kraus and Flood148 to the first synthesis of triethylgermylpotassium. Its reaction with ethyl bromide resulted in E Ge. However, attempts to cleave hexamethyldigermane either by potassium or by its alloy with sodium were unsuccessful228. 

Because of the great interest in the naturally occurring nucleosides, studies of the synthesis of D-ribosides of purines and pyrimidines have been numerous. The first attempt in this direction was made by Levene and Sobotka146 who condensed the silver salt of theophylline with tri-acetyl- 8-D-ribopyranosyl bromide to obtain what was probably triacetyl-7- 8-D-ribopyranosyl theophylline (LXXVI). Subsequently Hilbert and Rist94 condensed 2,4-diethoxypyrimidine (LXXVII) with triacetyl-0-D-ribopyranosyl bromide (LXXVIII) to form ethyl bromide and 1-triacetyl-D-ribopyranosyl-4-ethoxyuracil (LXXX), which, on deacetylation with hydrogen chloride, gave 1-D-ribopyranosyluracil (LXXIX), an isomer of... 

Simple saturated nitriles are seldom prepared by the decarboxylation of cyano acids derived from the cyanoacetic ester synthesis (cf. method 265). However, difunctional compounds are frequently obtained by this route, as in the preparation of a-methyl-y-phenoxybutyronitrile from /3-phenoxy-ethyl bromide and ethyl methylcyanoacetate (52% over-all). ... 

Among the ether acids prepared by the malonic ester synthesis are 6-phenoxycaproii. acid (65% over-all) from S-phenoxybutyl bromide ana y-(o-anisyl)-butyric acid (80%) from /3-(o-anisyl)-ethyl bromide/ ... 

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