hydrobenzamide from benzaldehyde and ammonia

Everyone knows what is the product of reaction of formaldehyde with aqueous ammonia. Hexamethylenetetraamine.
https://en.wikipedia.org/wiki/Hexamethylenetetramine
Reactants in ratio 6 aldehyde + 4 ammonia. Nice regular space structured molecule.

Less people know what is the product of reaction of acetaldehyde with aqeous ammonia. It is Acetaldehyde ammonia trimer
https://en.wikipedia.org/wiki/Acetaldehyde_ammonia_trimer
Reactants in ratio 3 aldehyde + 3 ammonia. Nice planar ring molecule.

Even less people know what is the product of reaction of benzaldehyde with aqueous ammonia. It is hydrobenzamide. Molecule not so much symmetrically shaped as the previous 2. But useful in preparation of further compounds. There is also a possibility to form a trimer product in certain solvents (see lozynskaya2003.pdf or the corresponding link, look there for "scheme 2").





Enough of words, let's do something and investigate it practically!
Usefull info grabbed over internet:
https://prepchem.com/synthesis-of-hydrobenzamide/
https://illumina-chemie.de/viewtopic.php?t=3657

10,5g benzaldehyde + 50 ml 25% NH3 magnetically stirred at highest possible RPM for 2 hours in 50 ml Erlenmayer flask which neck airtightly closed with plastic sheet (so only very little of air present), then let to stay for 3 days. Hard product adhering to the bottom formed, solution of remained ammonia poured out and the product broken to smaller pieces with thick glass rod.
Crystalized from 96% ethanol (free of denaturing agents like denatonium benzoate because I want to taste 1 of its derivates which should taste bitter). On the first recrystallization from 50 ml of ethanol an oil separated which later solidified, so I decided to recrystallize it again from 50 ml ethanol when nothing crystallized after hours, but I put it into freezer at -18 C for 1 week and then the product crystallized. Filtered and air dried on filter paper. Still some decent scent resembling benzaldehyd present. Perhaps it decomposes back into reactants in the 96% ethanol on heating? I did not use freshly distilled benzaldehyde as reactant so maybe the first crystallization when oil separated was caused by some benzoic acid contamination?
yield 5,3 g (cca 50%, not too much perhaps due the necessity of 2 crystallizations? or contamination with benzoic acid so less benzaldehyde reacted = oxidation with air oxygen which destroys benzaldehyde?)
m.p. 100-103 C





Now what it could be used for:
hydrobenzamide -> amarine -> lophine (weak chemiluminiscent)
hydrobenzamide -> amarine -> isoamarine -> stilbenediamine (investigating complexes, especially with Ni see the attached corey1997.pdf or the link, Co see williams1959.pdf or the link, also see lifschitz1940.pdf or the link)

http://www.chemspider.com/Chemical-Structure.7841195.html
melting point:
102-105 °C Alfa Aesar
104 °C Jean-Claude Bradley Open Melting Point Dataset 7312
102-105 °C Alfa Aesar H53492
102-105 °C Sigma-Aldrich ALDRICH-167649

https://books.google.cz/books?id=jgZLDwAAQBAJ&pg=PA679&a...
679.png

https://books.google.cz/books?id=MAvDDwAAQBAJ&pg=PT92&am...
toxicity.png

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphys...

https://ru.wikipedia.org/wiki/%D0%90%D0%BC%D0%B0%D1%80%D0%B8...
amarin.zip

https://sci-hub.st/10.1002/cber.188001301197
fisher1880.pdf

https://youtu.be/8XOKsHRp-f0
lophine from benzil + benzaldehyde + NH3HCO3 + acetic acid

https://sci-hub.st/10.1021/ed083p1658
crouch2006.pdf
from benzaldehyde and benzil in microwave

https://www.nature.com/articles/s41467-019-08816-8
https://www.nature.com/articles/s41467-019-08816-8.pdf
https://static-content.springer.com/esm/art%3A10.1038%2Fs414...
lophine hydroperoxide synthesis

https://sci-hub.st/10.1039/C4PP00311J
alves2015.pdf
chemiluminiscence mechanism

https://prepchem.com/synthesis-of-hydrobenzamide/
Preparation of hydrobenzamide
5 ml of benzaldehyde and 25 ml conc. ammonium hydroxide solution are placed in a stoppered flask and allowed to stand for 2 days. Crystals of hydrobenzamide separate, which are filtered off, washed with water, and recrystallised from alcohol. Yield 90% theoretical (4.2 gms.). m.p. 110° C; insoluble in water, easily soluble in alcohol.
Systematic organic chemistry, by W. M. Cumming, 307, 1937.

https://sci-hub.st/10.1023/A:1023915024572
lozinskaya2003.pdf

https://www.sigmaaldrich.com/catalog/product/aldrich/167649?...
A simplified synthesis of (?)-1, 2-diphenyl-1, 2-diaminoethane (1) from benzaldehyde and ammonia. Revision of the structures of the long-known intermediates ?hydrobenzamide? and ?amarine?. Corey EJ and Kuhnle FNM. Tetrahedron Letters 38(50), 8631-8634, (1997)
Synthesis and solution studies of Cu (II) complexes with pyridine derivatives of iminobisphosphonic acids. Goldeman W, et al. Inorgorganica Chimica Acta 365(1), 391-399, (2011)

https://sci-hub.st/10.1016/S0040-4039(97)10372-0
corey1997.pdf

https://sci-hub.st/10.1021/ja01526a007
williams1959.pdf
https://sci-hub.st/10.1002/recl.19400590208
lifschitz1940.pdf

sources downloaded for the case they disappear



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continuation of sources downloaded for the case they disappear

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Quote: Originally posted by Fery

DraconicAcid: look into the links referenced in the 1st post or download the attached files from one of the following posts: Cobalt complexes https://sci-hub.st/10.1021/ja01526a007 williams1959.pdf Nickel complex (it is in Deutsche Sprache - Die Nickelkomplexe) - again referenced in my first post and download available in one of the following posts https://sci-hub.st/10.1002/recl.19400590208 lifschitz1940.pdf

synthesis in ethanol environment

I prepared NH3 in ethanol:
Absorbtion bottle with sintered tube was filled with 40,0 g 96% ethanol using syringe and needle as this otherwise powerful absorbtion bottle has a disadvantage that it cannot be disassembled. Commercial denatured ethanol refluxed with NaOH to get rid of 1,6% MEK and distilled to get rid of denatonium benzoate was used.
The NH3 generator was a 250 ml flask which was charged with 0,5 mol (NH4)2SO4. 1 mol NaOH was dissolved in 50 ml H2O in a beaker while cooling in cold water bath. The NaOH solution was added at once to the generator and the flask was quickly closed with well greased take-off adapter connected with 2 m long hose which other end was connected to the absorbtion bottle. The gas was driven slightly upwards so eventual H2O vapor condensation could not drop into the absorbtion bottle. It was done outside of building at temperature 0 C so the hose served also as an condenser. The NH3 evolution started immediately and the flask was shaken in hand and later heated in hot oil bath until the evolution of NH3 ceased. The weight increase of the absorbtion bottle showed that the NH3 concentration was 14 %. Later I charged the same flask with 0,25 mole of (NH4)2SO4 and added to it 0,5 mol of solid NaOH and then added 5 ml of water to start the reaction. The flask was again shaken and heated in hot oil bath until the evolution of NH3 finished.
Weight difference of the absorbtion bottle showed that 7,8 g NH3 absorbed totally in 40,0 g of ethanol at the end of second gassing. Both gassings together lasted slightly more than 1 hour. The absorbtion bottle was cooled by cold surrounding air (actual outside temperature 0 C) as the absorbtion was exothermic. So final NH3 weight concentration was 16%. There was also an increase in volume (the black mark on the absorbtion bottle was original volume.





10,6 g benzaldehyde (100 mmol, M=106,12 g/mol) + 7,8 g NH3 in 40 g of ethanol mixed in 100 ml Erlenmayer flask, closed with plastic sheet and rubber band (to reduce banzaldehyde oxydation by air oxygen as much as possible) and placed outside for the night (outside temperature 0 C) as the gas evolution immediately visible on the plastic which was expanding like a bubble. Nothing crystallized overnight at 0 C outside temperature (perhaps supersaturated solution with lack of crystallization cores?). I placed it into freezer to - 18C and checked the next day and there was white solid product already. At this moment I had to go to Christmas and New Year holiday so I let it further in the freezer for 2 weeks (this is very likely unnecessary but I had to go).
Then filtered on sintered funnel outside of building at - 6 C outside temperature and washed 2 times with 10 ml of ethanol (bottle of ethanol chilled in freezer to -18 C) - both times after sucking out previous liquor and adding fresh ethanol the product was thoroughly stirred on the sintered funnel with the fresh solvent using a glass rod and only then sucked.
Air dried inside at 20 C for 1 day, last 6 hours there was no weight loss (no evaporation of remainders of solvent anymore).
Yield 9,4 g (31,5 mmol, M=298,4 g/mol) = 94,5%
m.p. 100-102 C
This way does not require recrystallization and the yield is almost twice of the yield using 25% water ammonia solution which required 2 recrystallization which caused significant loses.





After 1 day at 0 C nothing crystallized at 0 C but after another day in freezer at -18 C there was a white product





dried product



[Edited on 12-1-2021 by Fery]

Very nice yield, Fery! Using ethanolic NH3 is good improvement .