Thank you for the great video, but I have one question:
It says that hypophosphoric acid was added dropwise but also says H3PO2, which I think is hypophosphorous acid?
I might be wrong but can someone please clarify, because I always though hypophosphoric acid is H4P2O6 and hypophosphorus acid is H3PO2?
I see the ops as a dog pill, this is to be extracted somehow ? Basic dissolving or something more detailed. Or can I find the propanolanime somewhere else ?
Thank you for the great video, but I have one question: It says that hypophosphoric acid was added dropwise but also says H3PO2, which I think is hypophosphorous acid? I might be wrong but can someone please clarify, because I always though hypophosphoric acid is H4P2O6 and hypophosphorus acid is H3PO2?
i would additionally recommend a tube adaptor, for gas outlet etc. and then attach a pvc hose piece with two good latex balloons, on over another, well isolated with insulation tape and cable binders ...
set this apparatus after the initial reaction is calmed down in place....
and PPA tends to form the bis-compound....a few drops acetic acid decrease the formation of this undesired side product severely!
for workup simplification, use naphta (common camper fuel ) and after extraction of freebase amine, add 50-100mls of cold water, then titrate with diluted acid to the required ph level dropwise...
then separate and evape the aqueous layer on a pyrex dish preferably on a mag-stir hotplate, with a stir bar on steady pace, over the plate apply ventilation by pocket fan or alike....
by the way a PPA preparation via knoevenagel pn2p-OL (triethylamine instead otherwise, works best) in NaOH solution....
i reduced it by several techniques... but surprisingly sulfuric acid and zinc was efficient and easy prepared ! (zinc dust an Cu2Cl in EtOH sulf.acid solution per addition funnel over a longer time range)
<- i can say by rule, it is always a good reaction thriving factor, adding powdered active charcoal to reductions of many kinds, it creates a sponge like surface for hydrogen to more efficiently interacting with given precursor. works even with I2/P or HI
By the way auric.tetrachloride is a possible alternative to hg-salts....worked for me...
prepare alu-squares in same manner as with hg-salts...
tetrachloroaurate is made by gold dust with conc. HCL and 9% H2O2 on heat.....
then concentrate and dilute with DH2O
thats what "skilled in the art " people shouldnt state... try to be cautious and handle with precision and required equipment to properly fulfill given procedure....otherwise please dont start stripping li-ion batts. and burp the bottle type shit.....just buy the speedy substance like regular mo-fos do...
there isn’t much of a difference in this synth or any other synth, it all ends up the same if that’s what u r talking about. Doing a different synth just to be able to do more skillful chemistry is always good. But I don’t like unnecessary fumes or stains if there are other routes to take. I like new techs but that doesn’t mean I actualy like the tech. Iodine techs being one I don’t like cuz I simply do t enjoy the synth. It’s like if u could drive a bumpy road or take the highway. I dont buy from people or take any myself. And one pots are just the same as any other tech, just depends on who does it. It’s all a matter of choice and opinion. I haven’t gotten too far in the chem art world. Just above basic I would say. But it’s a process to say the least and useful to understand.
so, for your quest, i have to point at the fact, that especially HI / iodine related routes are pretty doable even for almost non experienced aspiring wizards...
as for the fumes attach kiddy balloons on the flask, its very easy to be clean then and stains should be no issue since you should use cupcake -paper baking forms. they are coated and very handy even in sticky substance situations...and they weigh all the same amount so easy tare your scale...
after the reaction is done neutralise the iodine simply by basing the mixture, it bonds to become NaI and stays in the liquor, so doesnt get in your product.
as for Al-amalgamum i would avoid this toxic waste producing route completely...
you can look up the new variant of the catalyst poisoning with gallium and SnCL instead of mercuric salt ...works with practise at least acceptable ! guaranteed...some types of the urushibara catalyst reductions are also reliable, but lower yielding....hope got u some to be of use. cheers
It definitely does work and is easier to do than the P2NP synthesis + reduction.
The biggest problem is obtaining a sufficient amount of PPA to begin with, and if you need to synthesize it yourself it would probably be easier to do a P2P/P2NP reduction. Iodine and hypophosphorus acid are both hard to obtain though, and if you fuck up with hypo it will realease phospine, which can (and will) kill you if you're exposed to it.
I MODIFIED THIS ONE BY USING TOLUENE AS MEDIUM AND ADD GAA , THEN SETUP A DEAN STARK APPARATUS AND HEAT THE ALANINE WITH THE BENZALDEHYDE UNTIL FIZZING STOPS.
This refined procedure promotos the decarboxylation mechanism and with consequent removal of waterthe desired product could be significantly obtained in fairer yields. (also less side reactions !)
but overall this route isn´t preferable over the ones commonly known in the art. (i prefer the p2np-ol route , like the normal henry/knoevenagel condensation, but with NaOH / triethylamine as Catalyst, - this gave more of the preferable , active isomer. hence its an assymetric synthesis.
I MODIFIED THIS ONE BY USING TOLUENE AS MEDIUM AND ADD GAA , THEN SETUP A DEAN STARK APPARATUS AND HEAT THE ALANINE WITH THE BENZALDEHYDE UNTIL FIZZING STOPS.
This refined procedure promotos the decarboxylation mechanism and with consequent removal of waterthe desired product could be significantly obtained in fairer yields. (also less side reactions !)
but overall this route isn´t preferable over the ones commonly known in the art. (i prefer the p2np-ol route , like the normal henry/knoevenagel condensation, but with NaOH / triethylamine as Catalyst, - this gave more of the preferable , active isomer. hence its an assymetric synthesis.
oh yes, sorry...i do over simplify nomenclature sometimes ..... try to
write more precise from now.
Phenyl-2-nitropropanol was the one i mentioned...
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FOR THE RECORD, a summary: -> [ i got the best result with example 2! ]
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Example 1
Nitroethane (10.2g, 0.132 mole) was mixed with triethylamine (17.1g, 0.169 mole), cooled to a temperature of -8°C and benzaldehyde (5.1g, 0.047 mole) added. After 2.7 hours at -10°C, the mixture was neutralized. HPLC analysis showed a conversion of 8.25g (96.9%) of total 2-nitro-1-phenyl-1-propanol. 6.40g of the 2-nitro-1-phenyl-1-propanol was the (1R*,2S*)-stereoisomer (77.6%).
Example 2
Nitroethane (15.6g, 0.208 mole) was mixed with triethylamine (17.1g, 0.169 mole), cooled to a temperature of -8°C and benzaldehyde (5.02g, 0.047 mole) added. After 2.25 hour reaction time, at -10°C, the mixture was neutralized. HPLC analysis showed a conversion of 8.30g (96.9%) of total 2-nitro-1-phenyl-1-propanol with a (1R*,2S*)-stereoisomer content of 6.11g (74.1 %).
Control 1 (Method of Vanderbilt and Hass)
Benzaldehyde (13.28 g, 0.125 mole), nitroethane (9.41g, 0.125 mole), 47.5 ml of SDA-2B ethanol and 3.5 ml of water were mixed and 1 ml of sodium hydroxide solution (50%) was added with cooling. After a 75 hour reaction time, at room temperature, the sodium hydroxide was neutralized. HPLC analysis showed a conversion of 16.2g (71.6%) of total 2-nitro-1-phenyl-1-propanol with an amount of (1R*,2S*)-stereoisomer of 5.5g (33.9%).
Control II (Modified Method of Vanderbilt and Hass)
Benzaldehyde (13.29g, 0.125 mole), nitroethane (9.39 g., 0.125 mole), 47.5 ml of SDA-2B ethanol and 3.5 ml of water were mixed and cooled to -10°C. To the cooled mixture was added 1.0 ml of sodium hydroxide solution (50%) and the reaction was allowed to proceed for 75 hours, at -10°C, after which time the sodium hydroxide was neutralized. HPLC analysis showed a conversion of 19.3g (85.4%) of total 2-nitro-1-phenyl-1-propanol with a (1R*,2S*)-isomer content of 6.4g (33.1 %).
Control III (Method of Kamlet)
Benzaldehyde (106.1 g., 1.0 mole) was agitated with sodium bisulfite (100.6 g., 1.06 mole) in 500 ml of water for 30 minutes. Separately, nitroethane (82.5 g., 1.10 mole) was dissolved, with cooling, in a solution made from 50% sodium hydroxide (90.9 g., 1.13 mole) and 155 ml of water. This mixture was added, over a period of 15 minutes, at 25°C, with vigorous agitation to the addition product of benzaldehyde and sodium bisulfite. After stirring overnight, the lower layer was discarded. HPLC analysis of the upper layer showed a conversion of 125.4 g. (69.3%) of total 2-nitro-1-phenyl-1-propanol with a (1R*,2S*)-isomer content of 43.9 g. (35.1 %).
