Author Topic: A new route to 4-(N,N-dimethylamino)butanal  (Read 4025 times)

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Vaillo

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A new route to 4-(N,N-dimethylamino)butanal
« on: August 31, 2003, 01:16:00 PM »
SWIM attempted following synthesis:

 An autoclave was loaded with 85 ml dry xylene,5.4 g (0.05 mol)of fresh phenylhydrazine,50 mg HRh(CO)(PPh)3,200 mg PPh3,5 g molecular sieves (powder).Autoclave was closed,mixture was kept under pressure 50 atm of syn-gas (CO:H2 1:1) and temperature 85 C  during 0.5 h.Then 10 ml of xylene with 6.5 ml of dimethylallyl amine was added from a dozator.After an 1 h conversion was about 100%.RM cooled,filtered and purefied on silicagel.When solvent was stripped off in vacuo,residue was taken up into 100 ml of 4% H2SO4 and refuxed 2 h.After that mixture neutralizied with 30 ml 20% NH4OH,5 g of activated coal added and refuxed another 15 min.Then cooled,extracted with dichloromethane and solvent evaporated.Residue diluted with small ammount of absolute ethanol and 2 g of picric acid in 10 ml of the same sol. was added.Picrate filtered and recrystallized from athanol.Thus way there were obtained 1.2 g DMT picrate which was proven by Erlich-colored reaction,M.P. 165 C and  mass-spectrum analysis.

PS The most great drawback of this reaction is a spontaneous aldol-type condensation of 4-(N,N-dimethylamino)butanal in the presence on Rhodium catalyst.It is this reason that a conversion of phenylhydrazine is so low.May be changing reaction conditions and catalysts would lead to more good outputs,but  unfortunately SWIM's work was stopped...

PS PS There is an awful mistake in the  link

https://www.thevespiary.org/rhodium/Rhodium/chemistry/dmten.html

namely in article J.Org.Chem. 1994,59,3738-3741 where authors,intentional IMHO,wrote about 4% sulfuric acid conditions for preparation of DMT-derivatives.
VERY IMPORTANT!These conditions (very strong!)suit to DMT preparation ONLY!Proved by SWIM himself with 5-MeO-DMT:
if any electron donating group (Meth,MeO etc) placed in phenylic nucleo,it leads to direct polymerization (dimer and trimer) of DMT-deriv.SWIM got only bubble-gum mass instead of desired substance.Read an  article of the same authors J.Org.Chem. 1997 9192-9202,where they tried phosphoric acid also but without any improvement!
Shame on them - they didn't read article Croatica Chemica Acta 36 (1964) 103 p where reaction runs smoothly in 25% acetic acid.SWIM went this way and got output about 67% of vacuo distilled MeO-DMT (185 C/5 mm) going from 4-(N,N-dimethylamino)butanal dimethyl acetal (Rosenmund reduction of  4-chlorobutyryl chloride).

Edit: The latter article has been posted in

Post 481048

(dioulasso: "Fisher w/ AcOH", Tryptamine Chemistry)

Lilienthal

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What temperature did you use in the ...
« Reply #1 on: August 31, 2003, 02:27:00 PM »
What temperature did you use in the 5-MeO-phenylhydrazine reaction with 4% sulfuric acid?

Vaillo

  • Guest
Following this article mixture refuxed 2 hours
« Reply #2 on: August 31, 2003, 02:40:00 PM »
very harsh conditions you see

Lilienthal

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Post 17677 :-)
« Reply #3 on: August 31, 2003, 04:54:00 PM »

Post 17677

(C_Nemo: "useful tryptamine methods", Tryptamine Chemistry)
 :)

Vaillo

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If SWIM had known it he wouldn't loose his first
« Reply #4 on: August 31, 2003, 08:59:00 PM »
portion of 30g of 4-(N,N-dimethylamino)butanal dimethyl acetal 7 years ago  :)