Bubbleplate (Hive Bee)
11-26-02 13:46
No 383664
      MethylMan Al/Hg Nitro Modifications and Questions  Bookmark   

Finally got the MM Al/Hg Nitro reduction to work decently, but yields are still not what I'd like them to be.
Better yields have come from:
Switching to 99.99% Nitro (no Fuel Oil BS)and using excess (30 gm)
Adding small amount (15-25 ml) dH2O to Methanol
Using excess Al (33-35 gm)
And of course adding Nitro before adding Ketone.
But I still have questions:
1) How many minutes after adding ALL the Nitro should Ketone drip be started? How long to add all?
2) What is the temperature, approx., that the Nitro and Ketone addition reactions should run at? (I don't recall MM or anyone mentioning this)I'm seeing 55-60 C. Too low/high?
3) MM states to add 750 ml of 35% NaOH to the post reduction mixture. I have monitored the pH of the mixture and have found that adding just even 350 ml of 35% NaOH pushes the pH to 13 or greater! Is it necessary to add 750 ml, and will "over basifying" the mix hurt the yield or product?
4) Does the standard MM formula allow the Al/Hg to have enough "reduction potential" left for the Ketone if one adds all the Nitromethane first?
One last observation: reactions using Hg Chloride/Methanol mixed up the day before as opposed to right before use, took much longer for the amalgamation to start (30+ minutes)and did not run as well. No explanation for that one!
(Hive Bee)
11-26-02 16:10
No 383724
      This thread has been started 10x already  Bookmark   

1) You don't have to add ALL of your nitro before you start add the ketone to get good results.

2) Visually determined by reflux.

3) I dont think it will "hurt" yield, although it may make the workup more difficult, ie emulsions. The amount of base needed will be determined by how much product you actually made. If you only need half did you only yield half??

4) Suggestion, add half the nitro, then add your ketone, and have the drip completed in 30 minutes. Adding the water may help, but in that much excess.. I dunno. Sometimes after washing a rb after a rxn, I just leave the few drops of water in there and call it 5ml's.

What exactly are your yields!? The more info you provide, the more you can be helped.

>>One last observation: reactions using Hg Chloride/Methanol mixed up the day
>>before as opposed to right before use, took much longer for the amalgamation
>>to start (30+ minutes)and did not run as well.

huh? 30+ minutes is long??

Are you ending up with a lot of foil left over after the rxn?
(Chef d'Equippe)
12-02-02 05:49
No 385486
      Read my old post "kickin up the yields", that ...  Bookmark   

Read my old post "kickin up the yields", that will point you in the right direction for a better yield. You dont need to add anyonething first or seperately, or get elaborate on the addition process in order to yield higher. Thats all a bunch of supersticious, unsubstantiated tripe. Huge waste of time & also pointless to add extra steps/work to a simple working process that is already a proven top yielder as written. Failure/low yields is usually from ones' deterring from the original reaction details(sloppy technique) or using dirty reagents. The wheel is already round, trying to re-invent it wont make that triangle roll any faster.  

Shoot Narcs, Not Drugs
(Hive Bee)
12-03-02 06:04
No 385802
      Could You Point Out That Post  Bookmark   

USING the FSE on you and "kicking up the.." gets nada.
(Hive Addict)
12-03-02 15:08
No 385920
      open mouth, insert spoon  Bookmark   

it's feeding time

start here... Post 53662 (baalchemist: "Al/Hg-Nitro kickin up the yield", Methods Discourse)

Now with 12% more Bottom!
Nymphomania is not a disease, its a goal! (Methadist)
(Master Searcher)
12-03-02 15:29
No 385933
      kickin  Bookmark   

kickin needs to be spelled incorrectly.

The hardest thing to explain is the obvious
(Hive Bee)
12-03-02 17:45
No 385978
      Thanks For That Spoon Feed Honey Bees!  Bookmark   

SWIM has like 5 minutes spare time lately to do searches...