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All 13 posts Subject: Bromoethane synthesis Please login to post Down

lastchance
(Stranger)
09-04-04 19:37
No 529574
      Bromoethane synthesis

Just in case anyone knows or cares Nitroethane can be easily made with Bromoethane and Sodium Nitrite. Problem being is Bromoethane is primarily a soil fumigate and from what I hear the EPA has pretty much bannned it due to high toxity and other alternatives. Are there any decent synthesis to make Bromoethane (Ethyl Bromide)? I am refering to Rhodiums method 3 Nitroethane Synthesis: A Compilation

Lestat
(Hive Bee)
09-04-04 20:32
No 529576
User Picture       Direct bromination of the alcohol would, in...

Direct bromination of the alcohol would, in this case, yield bromal hydrate (similar to chloral, but don't get any ideas, its a LOT more toxic)

What about gassing of bromine with ethane?

Edit: Would the same procedure using methyl bromide yield nitromethane?

Non omnis moriar, tenebris й clarior

Captain_America
(Hive Bee)
09-04-04 22:06
No 529588
      EtX

For the swap consider making iodoethane. There is a writeup posted by russian bees using KI Post 301629 (Antoncho: "Two tried-and-true ways to make MeI !", Chemistry Discourse) it will work for EtI too.

Btw, why not make the nitroethane from ethanol, sulfuric and NaNO2 and avoid that extra step? UTFSE: Post 233762 (Antoncho: "Kitchen nitroalkane success!", Chemistry Discourse)

If you still prefer the swap, maybee try PTC...

Bee sure to report back!

gsus
(Hive Bee)
09-04-04 23:21
No 529600
      ethyl bromide

the nitroalkane FAQ, right above the compilation.

farther down, Vogel, pp. 278-9. or any other book of that sort of the last 150 years.

http://www.druglibrary.org/toc.htm

karl
(Hive Bee)
09-05-04 13:10
No 529680
User Picture       If you do a search you will find that myself...

If you do a search you will find that myself and some others have had problems with Bromoethane and NaNO2 with DMSO or DMF - It looked good on one of the references where they tested it extensively for nitromethane, but I think their data on nitroethane was a bit dubious.

Fuck the creationists - MC Hawking

hest
(Hive Adickt)
09-05-04 14:07
No 529683
      Nitroethane

so doo I.
I have truet the reaction 5-10 times, with realye crapye yeald's (in the 5-15% range).
Next time I use silvernitrite instead

cattleprodder
(Hive Bee)
09-06-04 00:46
No 529779
      Bromoethane synthesis

What about ethyl alcohol plus phosphorous tribromide?

EtOH + PBr3 --> EtBr

moo
(Hive Addict)
09-06-04 16:40
No 529909
      You could do that... but why use a reagent...

You could do that... but why use a reagent that has much better uses to do something you can pull off with sulfuric acid and a bromide salt?

_{fear fear hate hate}

Captain_America
(Hive Bee)
09-08-04 12:17
No 530301
      Reference missing?

https://www.rhodium.ws/chemistry/nitroalkane.html

Preparation of Ethyl Bromide

1500 ml of concentrated H2SO4 was added to 900 ml H2O, then cooled. Then 1.5 l of absolute ethanol was slowly dripped in, carefully to avoid temperature rise. Cool the mixture and add 1100-1200 g KBr (or equimolar amount of NaBr). Heat the mixture on a sand-bath at the lowest temperature at which the ethylbromide distills over, collect it in water. Wash the ethyl bromide again with water and dry it with CaCl2. Yield 90-96%.

What's the ref for this prep? Using KI instead of KBr would probably give as good results for EtI, since it is almost identical to the synth posted by Antoncho, don't you think so? Great method.

Rhodium
(Chief Bee)
09-08-04 14:55
No 530310
User Picture       The preparation of ethyl bromide

The missing reference is one of the two following ones, but I don't know which one:

I. The preparation of ethyl bromide
Alfred Holt, J. Chem. Soc., Trans., 109, 1-2 (1916)
DOI:10.1039/CT9160900001

CLXIV. The preparation of ethyl bromide
Frank Edwin Weston, J. Chem. Soc., Trans., 107, 1489-1490 (1915)
DOI:10.1039/CT9150701489

I also happened to find this reference in connection to the two above, maybe it is of interest as well:

CCCLIX. The effect of intensive drying on the rate of distillation and on the vapour pressure of ethyl bromide
John William Smith, Journal of the Chemical Society 2573-2583 (1931)
DOI:10.1039/JR9310002573

^{The Hive - Clandestine Chemists Without Borders}

lugh
(Moderator)
09-10-04 02:17
No 530575
      Another Old Ethyl Bromide Preparation
(Rated as: good read)

From Cohen's Practical Organic Chemistry

Ethyl Bromide (Monobromethane), C₂H₅Br.
De Vrij, Jahresber., 441 (1857)

100 grms potassium bromide.
100 grms (54 c.c.) conc. sulphuric acid.
60 grms (75 c.c). absolute alcohol

Fit up the apparatus as shown. The distilling flask should have a capacity of not less than I litre, and is attached to a long condenser. An adapter is fixed to the end of the condenser, dipping into a conical flask (250 c.c.), which serves as receiver. The alcohol and sulphuric acid are mixed in the distilling flask and cooled to the ordinary temperature tinder the tap. The potassium bromide, coarsely powdered, is then added. The flask, which is closed with a cork, is fixed to the condenser and heated on the sand-bath. A sufficient quantity of water is poured into the receiver to close the end of the adapter. After a short time the liquid in the flask begins to boil and froth up, and the ethyl bromide, in the form of heavy drops of colourless liquid, distils and collects at the bottom of the receiver. If the liquid threatens to froth over, the flask must be raised from the sand-bath for a moment. The distillation is continued until no further drops of oil appear at the end of the condenser. As the ethyl bromide has a low boiling point (38-39c), it is desirable to surround the receiver with ice during this operation. The distillate is now removed and poured into a separating funnel, and the lower layer of ethyl bromide separated. The water is thrown away and the ethyl bromide poured back together with about an equal bulk of dilute sodium carbonate solution and shaken up. The ethyl bromide is withdrawn, as before, and again shaken up with water. Finally, it is carefully separated from the water and run into a dry distilling flask. The small quantity of water which remains. and renders the liquid turbid, is removed by adding a dehydrating agent.
Dehydration. Moisture can be readily removed from liquids by adding a solid hygroscopic substance which does not act chemically upon the liquid. The common dehydrating agents are calcium chloride, potassium carbonate, sodium sulphate (anhydrous), quicklime, etc. Alkalis can not of course be used for dehydrating organic acids, nor can calcium chloride be employed in conjunction with alcohols or organic bases, with which it combines. In the present instance it can be used. A few small pieces of the granulated or fused calcium chloride are added to the liquid. The flask is corked and left to stand for some hours until the liquid becomes clear. It is then distilled. A thermometer is inserted into the neck of the flask with the bulb just below the side tube. The flask is attached to a condenser and heated gently on the water bath, so that the liquid distils at a moderate speed (2-3 drops a second). The temperature is noted and the portion boiling at 35-43° collected in a separate flask. This consists of ethyl bromide which may contain a little ether. Yield 75-80 grams.

Chemistry is our Covalent Bond

Kinetic
(Hive Bee)
09-11-04 15:05
No 530855
      Preparation of ethyl bromide
(Rated as: excellent)

Here are the two articles requested by Captain_America:

CLXIV. The preparation of ethyl bromide
Frank Edwin Weston
Journal of the Chemical Society, Transactions, 107, 1489-1490 (1915)

I. The preparation of ethyl bromide
Alfred Holt
Journal of the Chemical Society, Transactions, 109, 1-2 (1916)

Captain_America
(Über-Führer die Ironie)
11-03-04 01:15
No 539297
      tnx K

ALKYL AND ALKYLENE BROMIDES:

http://www.orgsyn.org/orgsyn/orgsyn/prepcontent.asp?print=1&showprint=1&prep=cv1p0025

http://www.junkmusik.com/junkvideo.mov

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	All 13 posts		Subject: Bromoethane synthesis		Please login to post		Down


		lastchance (Stranger) 09-04-04 19:37 No 529574				Bromoethane synthesis
						Just in case anyone knows or cares Nitroethane can be easily made with Bromoethane and Sodium Nitrite. Problem being is Bromoethane is primarily a soil fumigate and from what I hear the EPA has pretty much bannned it due to high toxity and other alternatives. Are there any decent synthesis to make Bromoethane (Ethyl Bromide)? I am refering to Rhodiums method 3 Nitroethane Synthesis: A Compilation



		Lestat (Hive Bee) 09-04-04 20:32 No 529576				Direct bromination of the alcohol would, in...
						Direct bromination of the alcohol would, in this case, yield bromal hydrate (similar to chloral, but don't get any ideas, its a LOT more toxic) What about gassing of bromine with ethane? Edit: Would the same procedure using methyl bromide yield nitromethane? Non omnis moriar, tenebris й clarior



		Captain_America (Hive Bee) 09-04-04 22:06 No 529588				EtX
						For the swap consider making iodoethane. There is a writeup posted by russian bees using KI Post 301629 (Antoncho: "Two tried-and-true ways to make MeI !", Chemistry Discourse) it will work for EtI too. Btw, why not make the nitroethane from ethanol, sulfuric and NaNO2 and avoid that extra step? UTFSE: Post 233762 (Antoncho: "Kitchen nitroalkane success!", Chemistry Discourse) If you still prefer the swap, maybee try PTC... Bee sure to report back!



		gsus (Hive Bee) 09-04-04 23:21 No 529600				ethyl bromide
						the nitroalkane FAQ, right above the compilation. farther down, Vogel, pp. 278-9. or any other book of that sort of the last 150 years. http://www.druglibrary.org/toc.htm



		karl (Hive Bee) 09-05-04 13:10 No 529680				If you do a search you will find that myself...
						If you do a search you will find that myself and some others have had problems with Bromoethane and NaNO2 with DMSO or DMF - It looked good on one of the references where they tested it extensively for nitromethane, but I think their data on nitroethane was a bit dubious. Fuck the creationists - MC Hawking



		hest (Hive Adickt) 09-05-04 14:07 No 529683				Nitroethane
						so doo I. I have truet the reaction 5-10 times, with realye crapye yeald's (in the 5-15% range). Next time I use silvernitrite instead



		cattleprodder (Hive Bee) 09-06-04 00:46 No 529779				Bromoethane synthesis
						What about ethyl alcohol plus phosphorous tribromide? EtOH + PBr3 --> EtBr



		moo (Hive Addict) 09-06-04 16:40 No 529909				You could do that... but why use a reagent...
						You could do that... but why use a reagent that has much better uses to do something you can pull off with sulfuric acid and a bromide salt? _{fear fear hate hate}



		Captain_America (Hive Bee) 09-08-04 12:17 No 530301				Reference missing?
						https://www.rhodium.ws/chemistry/nitroalkane.html Preparation of Ethyl Bromide 1500 ml of concentrated H2SO4 was added to 900 ml H2O, then cooled. Then 1.5 l of absolute ethanol was slowly dripped in, carefully to avoid temperature rise. Cool the mixture and add 1100-1200 g KBr (or equimolar amount of NaBr). Heat the mixture on a sand-bath at the lowest temperature at which the ethylbromide distills over, collect it in water. Wash the ethyl bromide again with water and dry it with CaCl2. Yield 90-96%. What's the ref for this prep? Using KI instead of KBr would probably give as good results for EtI, since it is almost identical to the synth posted by Antoncho, don't you think so? Great method.



		Rhodium (Chief Bee) 09-08-04 14:55 No 530310				The preparation of ethyl bromide
						The missing reference is one of the two following ones, but I don't know which one: I. The preparation of ethyl bromide Alfred Holt, J. Chem. Soc., Trans., 109, 1-2 (1916) DOI:10.1039/CT9160900001 CLXIV. The preparation of ethyl bromide Frank Edwin Weston, J. Chem. Soc., Trans., 107, 1489-1490 (1915) DOI:10.1039/CT9150701489 I also happened to find this reference in connection to the two above, maybe it is of interest as well: CCCLIX. The effect of intensive drying on the rate of distillation and on the vapour pressure of ethyl bromide John William Smith, Journal of the Chemical Society 2573-2583 (1931) DOI:10.1039/JR9310002573 ^{The Hive - Clandestine Chemists Without Borders}



		lugh (Moderator) 09-10-04 02:17 No 530575				Another Old Ethyl Bromide Preparation (Rated as: good read)
						From Cohen's Practical Organic Chemistry Ethyl Bromide (Monobromethane), C₂H₅Br. De Vrij, Jahresber., 441 (1857) 100 grms potassium bromide. 100 grms (54 c.c.) conc. sulphuric acid. 60 grms (75 c.c). absolute alcohol Fit up the apparatus as shown. The distilling flask should have a capacity of not less than I litre, and is attached to a long condenser. An adapter is fixed to the end of the condenser, dipping into a conical flask (250 c.c.), which serves as receiver. The alcohol and sulphuric acid are mixed in the distilling flask and cooled to the ordinary temperature tinder the tap. The potassium bromide, coarsely powdered, is then added. The flask, which is closed with a cork, is fixed to the condenser and heated on the sand-bath. A sufficient quantity of water is poured into the receiver to close the end of the adapter. After a short time the liquid in the flask begins to boil and froth up, and the ethyl bromide, in the form of heavy drops of colourless liquid, distils and collects at the bottom of the receiver. If the liquid threatens to froth over, the flask must be raised from the sand-bath for a moment. The distillation is continued until no further drops of oil appear at the end of the condenser. As the ethyl bromide has a low boiling point (38-39c), it is desirable to surround the receiver with ice during this operation. The distillate is now removed and poured into a separating funnel, and the lower layer of ethyl bromide separated. The water is thrown away and the ethyl bromide poured back together with about an equal bulk of dilute sodium carbonate solution and shaken up. The ethyl bromide is withdrawn, as before, and again shaken up with water. Finally, it is carefully separated from the water and run into a dry distilling flask. The small quantity of water which remains. and renders the liquid turbid, is removed by adding a dehydrating agent. Dehydration. Moisture can be readily removed from liquids by adding a solid hygroscopic substance which does not act chemically upon the liquid. The common dehydrating agents are calcium chloride, potassium carbonate, sodium sulphate (anhydrous), quicklime, etc. Alkalis can not of course be used for dehydrating organic acids, nor can calcium chloride be employed in conjunction with alcohols or organic bases, with which it combines. In the present instance it can be used. A few small pieces of the granulated or fused calcium chloride are added to the liquid. The flask is corked and left to stand for some hours until the liquid becomes clear. It is then distilled. A thermometer is inserted into the neck of the flask with the bulb just below the side tube. The flask is attached to a condenser and heated gently on the water bath, so that the liquid distils at a moderate speed (2-3 drops a second). The temperature is noted and the portion boiling at 35-43° collected in a separate flask. This consists of ethyl bromide which may contain a little ether. Yield 75-80 grams. Chemistry is our Covalent Bond



		Kinetic (Hive Bee) 09-11-04 15:05 No 530855				Preparation of ethyl bromide (Rated as: excellent)
						Here are the two articles requested by Captain_America: CLXIV. The preparation of ethyl bromide Frank Edwin Weston Journal of the Chemical Society, Transactions, 107, 1489-1490 (1915) I. The preparation of ethyl bromide Alfred Holt Journal of the Chemical Society, Transactions, 109, 1-2 (1916)



		Captain_America (Über-Führer die Ironie) 11-03-04 01:15 No 539297				tnx K
						ALKYL AND ALKYLENE BROMIDES: http://www.orgsyn.org/orgsyn/orgsyn/prepcontent.asp?print=1&showprint=1&prep=cv1p0025 http://www.junkmusik.com/junkvideo.mov

All 13 posts	End of thread	Top