Author Topic: formylation by the "nitroso" method  (Read 2928 times)

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  • Guest
formylation by the "nitroso" method
« on: September 11, 2002, 08:32:00 AM »
Preparation of aromatic aldehydes by the "nitroso" method.
Eliseeva, V. N.; Devitskaya, T. A.   
Zhur. Priklad. Khim.  (1956),  29  1894-6.
CAN 51:39146    AN 1957:39146  

Stirring p-ONC6H4NMe2 (from 50 g. amine), 212 g. com. HCl, 25 g. MeOPh, and 10 g. urotropine(aka hexamine) in 20 ml. H2O 8 hrs. at 50° followed by steam distn. gave 44% anisaldehyde.  Similarly, 35 g. p-ONC6H4NMe2, 242 g. com. HCl, 0.4 g. ZnCl2, 25 g. MeOPh, and 10 g. urotropine in 20 g. H2O gave 56% anisaldehyde.  ONC6H4NMe2 (from 50 g. amine), 121 g. com. HCl, 0.4 g. ZnCl2, 25 g. o-CH2O2C6H4, and 7 g. urotropine stirred 8 hrs. at 50° and steam distd. gave 40% heliotropine; similarly, 35 g. p-ONC6H4NMe2, 121 g. com. HCl, 0.4 g. Al shavings, 25 g. o-CH2O2C6H4, and 7 g. urotropine stirred 8 hrs. at 50°, treated with 500 ml. H2O, heated 6 hrs. at 50°, extd. with C6H6, and the ext. distd. gave 42% heliotropin; the pure product, m. 36.5-7° (from EtOH). 

Preparation of aromatic aldehydes by the "nitroso" method.
Eliseeva, V. N.; Devitskaya, T. A.   
J. Appl. Chem. U.S.S.R.  (1956),  29  2043-5. 
Journal  written in English.  CAN 52:40390  AN 1958:40390
(I will get this article) 

Preparation of aromatic aldehydes by the nitroso method. II.
Eliseeva, V. N.; Devitskaya, T. A.; Laskina, E. D.   
Tr. Vses. Nauchn.-Issled. Inst. Sintetich. i Natural'n.
Dushistykk Veshchestv  (1961),   (No. 5),  18-21. 
CAN 57:55948    AN 1962:455948

cf. CA 51, 7326c.  The title compds. were prepd, by method described (lot. cit.) from phenols and their 0-derivs. by action of p-nitrosodimethylaniline and urotropine in the presence of A1 or a mixt. of CuSO4, MnSO4, and ZnCl2 and isolated either by steam distn. or (after hydrolysis) by extn. with org. solvents.  The phenol (O-alkylating group) and aldehydes prepd. from it, its % yield (% purity), b.p., m.p., n20D, d20, m.p. of corresponding oxime, and odor were given: o-cresol (Me), 4-methoxy-3-methylbenzaldehyde, 44 (99.26), b5-7 125-7°, -, 1.5698, 1.0337, 68-9.5°, like acetophenone; o-cresol (Et), 4-ethoxy-3-methylbenzaldehyde, 61)(100), b4-5 120-7°, 27-30°, -, -, 92.5-3.0°, like mixt. of heliotropin and obepin; o-cresol (Me), 6-methoxy-3-methylbenzaldehyde, 54(100), b3 104°, -, 1.5522, 1.0056, 143-4° like methyl salicylate; tert-butyl m-cresol (Me), methoxymetbyl-tert-butylbenzaldehyde (indeterminate structure), 54-68(99.6), b5 135-7°, 78-84°, -, -, 122-3°, disagreeable.  Similarly, methylguaiacol gave in poor yield 4-hydroxy-5-methoxy-2-methylbenzaldehyde (proposed structure), m. 172-3°.  Product of alkylation of optol (mixt. of pyrocatechol and its homologs) with CH2Cl2 gave 3,4-methylendioxy-6-methylbenzaldehyde (proposed structure), m. 86-7° (oxime, m. 89°), odor like heliotropin, p-Cresol yielded 6-hydroxy-3-methylbenzaldehyde in 24% yield, m. 53% oxime m. 103-4°. 1,2-Ethylenedioxybenzene gave 3,4-ethylendioxybenzaldehyde in 60% yield, m. 52.5°, with heliotropin-like odor.  An attempt to prep. by this method aldehydes from heliotropin, cumene, triisopropylbenzene, benzyl ale., and dibenzylformal was unsuccessful. 

Read and Listen!!!


  • Guest
Nice! Do you have a good preparation of ...
« Reply #1 on: September 11, 2002, 09:20:00 AM »
Nice! Do you have a good preparation of 4-Nitroso-N,N-dimethylaniline handy too?


  • Guest
Another EXCELLENT formylation!
« Reply #2 on: September 11, 2002, 09:48:00 AM »
Very good, Foxy!

Despite the fact that an equimolar qtty of the nitrosodimethylaniline is needed, this could bee a VERY good route to substituted BA's - ESPECIALLY so since it works on phenol ethers!

There is another patent that describes this formylation,

Patent GB145581

- tested on anisol and also some non-methylated phenols.

Seems like all one would need is to get some diMe (or Et) aniline - beecause p-nitroso-diMeaniline is real easy to prepare (


A solution of 300 g. (2.5 moles) of technical dimethylaniline in 1050 cc. of concentrated hydrochloric acid is placed in a large jar or crock and finely divided ice is added until the temperature has fallen to 5°. The contents of the jar are then stirred mechanically, and a solution of 180 g. (2.6 moles) of sodium nitrite in 300 cc. of water is slowly added from a separating funnel, the stem of which dips beneath the surface of the liquid. The addition takes one hour, and the temperature is kept below 8° by the addition of ice if necessary. When all the nitrite has been added the mixture is allowed to stand one hour and then filtered. The solid p-nitrosodimethylaniline hydrochloride is washed with 400 cc. of 1:1 hydrochloric acid and then with 100 cc. of alcohol. After drying in air, it weighs 370–410 g. (80–89 per cent of the theoretical amount) (Note 1).

Very, very interesting.... Hope someone tries this soon :)  (where i live, even dimethylaniline is way too expensive :) )



  • Guest
Zealot: azomethinic (Haack) formylation
« Reply #3 on: November 22, 2002, 08:33:00 AM »
Dear Bees!


Post 363743 (missing)

(zealot: "Ôîðìèëèðîâàíèå ïî Õààêó", Russian HyperLab)
has been lying on my HDD for some time now in the 'to translate ASAP' list. Finally, I got to it, I am happy to say. What you're about to read is a direct continuation of the topic started by Foxy2, but the improvements suggested and tested by Zealot make it something revolutionary different.

The difference is of course insignificant to the bees w/the access to real labs/equipment etc., but for us, kitchen chemists, it has a mind-blowing potential.

Read on. You'll see what I mean ;)

This rxn generally has a very wide range of variations, but for the purposes of a kitchen chemist, the following things should bee taken into concern:

1.   Formyl group is strongly deactivating to the phenolic hydroxies for further metylation, thus, it is desirable to carry out this synth w/completely etherified phenols. And since the latter aren't soluble in water, it is necessary to do the rxn in MeOH or EtOH.

2.   Traditionally, dinethylnitrosoaniline (NDMA) is used in this rxn – however, it is explained by its relative ease of preparation. The reality is that the yield is absolutely the same for both NDMA and p-nitrosophenol (NP) and rarely exceeds 50-60%.

3.   Since paraform is insoluble in alcohols, there's no advantage in using it; it is thus preferrable to use aq. 40% formaline as a cheaper substitute.

4.   The order of addition of the ingredients doesn't play a crucial role. NDMA isn't soluble in aqua, but dissolves in alcohols and dilute mineral acids. NP is soluble in alcohols, hot water, and hot mineral acids w/decomposition.

5.   The speed of the rxn should bee regulated w/addition of either nitroso comp'd or paraform/formaline, but NOT acid – on adding some critical qtty of it, the rxn beecomes uncontrollable and can easily bee spit out of the flask.


I. Anisaldehyde.

In a 500mls 3-necked RBF w/a RC, 20g anisole and 30g wet NP is dissolved in 200mls EtOH. One neck is equipped w/a thermometer, the other one – w/a tube w/a porous glass filter. Thru it there's bubbled a gentle stream of HCl for 10-15mins. Then it is replaced w/a addition funnel, thru which 22mls of 40% formaline is added w/mag stirring so that the tem is kept in interval of about 50-55 C. After the addition is oer, the soln is boiled for 1-1,5 hrs. EtOH is removed in vacuo (to minimize hydrolysis of the methoxies), 100mls 12% NaOH is added and the aldehyde is xtracted w/ether; then purified or simply steam-distilled from the rxn mixtr (applicable to anisaldehyde and piperonal only).

The yield – 13.3g (53% of theory)

II. Heliotropine (piperonal).

The synthesys is done in an analogous manner, using 20g benzodioxole, 26g NP and 18mls formaline.

Yield – 12g (47% of theory)

III. Veratraldehyde.
IV. 2,5-diMeO-benzaldehyde.

Obtained from 20g either o- or p-diMeO-benzene, yielding 14g (58%) and 13.5g (56%) respectively.
I want to note that for p-diMeO-BA, 56% is the upper limit I've ever been able to achieve. All in all, the para-isomer reacts worse than ortho- - probably, due to steric hindrance.

The following prep's of the intermediates were found and submitted by Chemister of HyperLab:

1. P-nitroso-dimethylaniline.

In a porcelain glass equipped w/a stirrer, thermometer and a dripping funnel there's mixed 10.3g (8,6mls) aq. HCl and 5g dimethylaniline (added into the acid), 40g crushed ice and slowly, w/constant stirring, keeping the temp beelow 10 C, there's added over an hour a soln of 3.1 NaNO2 in 10mls water. The rxn takes on an orange coloration and yellow crystals of p-NDMA hydrochloride are deposited. The contents are further stirred for 1hr, the p'p'tate is filtered off, well pressed on a porous plate, washed w/5mls EtOH and dried in an exicator.

Yield 7.2g (90%)

To get the freebase the product is treated in a sepfunnel w/5% Na2CO3 and 20mls ether. The base is xtracted into the ethereal layer which is separated and the solvent is removed. NDMA crystallizes as greenish scales. It can bee further purified by rextallization from pet ether.

2. P-nitrosophenol.

In a porcelain glass equipped w/a stirrer, thermometer and a dripping funnel there's placed 45mls water, dissolved in it are 4.6g NaNO2 and 5g phenol melted in 15mls water are added thereto. Into the mixtr there's added 60g crushed ice and from a addition funnel there's added over an hour a cold soln of 2mls H2SO4 in 7mls water. The addition is done w/intensive stirring and good salt/icebath cooling – the temp should bee kept at 0 C. The rxn is stirred at this temp for further 2hrs, the product is filtered, washed w/cold water until neutral to litmus and dried at 50-60 C.

Yield 5.2g (80%)

These were found by

Patent US3320324

Patent US3320324

Just some procedures for nitrosating phenol.

Ahhhhh……………. I got this burden off my shoulders finally :)  

And finally I'll go to bed. Sleeeeeeeeeeeeeeeeeep……………..

Tired but happy,


  • Guest
3,4,5-TMBA from Gallic Acid
« Reply #4 on: October 02, 2003, 02:50:00 AM »
The result of some mental masturbation as a form of work evasion:

1) Don't recall exact details but gallic acid decomposes at it's melting point to form pyrogallol,

(OH)3.C6H2.COOH __> (OH)3.C6H3 + CO2

2) Methylation (DMS is obvious choice but other agents may be applicable) to 1,2,3-trimethoxy benzene
3) Azomethinic formylation to 3,4,5-TMBA

Or alternatively methylenation and then methylation for myristicinaldehyde ?


  • Guest
sure ?
« Reply #5 on: October 02, 2003, 08:31:00 AM »
Are you sure this would give 345-TMBA, not 234-TMBA ? I've alwas only seen ortho formylations for trimethoxybenzene. Would bee too great !



  • Guest
2,6-Dimethoxyphenol -> Syringaldehyde
« Reply #6 on: October 02, 2003, 12:44:00 PM »
That's unfortunately correct... A quick Beilstein search revealed no direct routes from 1,2,3-trimethoxybenzene to 3,4,5-trimethoxybenzaldehyde.

2,6-Dimethoxyphenol is however easily formylated to 4-hydroxy-3,5-dimethoxybenzaldehyde (syringaldehyde):

CHCl3/NaOH: Chem. Ber. 36, 1033 (1903).

(i) CH3SCHCl2/SnCl4/CH2Cl2
(ii) HgCl2/HCl(aq)
Monatsh. Chem. 102, 425-430 (1971).

HMTA/Trifluoroacetic Acid: J. Med. Chem. 32(2), 450-455 (1989).

HMTA/Glycerol/Boric Acid: Can.J.Res.Sect.B 23, 100 (1945) and

Organic Syntheses, CV 4, 866



  • Guest
« Reply #7 on: October 02, 2003, 11:45:00 PM »
Oh yeah, didn't think of that  :-[ .


  • Guest
dimethylaniline preparation
« Reply #8 on: October 12, 2003, 12:58:00 PM »
aniline + MeOH + I2 (cat.) __> dimethylaniline

Here are a few but probably important words from

Patent DE250236


93 parts Aniline, 96 parts MeOH and 1 part I2 are heated to 230°C for 7h. The reaction product is separated from water and, after removal of I2 with alkalies, distilled in vacuo. Dimethylaniline is gained in quantitative yield.

Also works with EtOH: 235°C / 10h / 100%.

Edit: huh ? they don't say a word about overpressure neither in this patent nor in that to which it is an improvement, but how else are you supposed to keep MeOH at 230°C for 7h ? It surely boils below that, doesn't it ?



  • Guest
« Reply #9 on: October 12, 2003, 08:12:00 PM »
66° Bé H2SO4 is the same as ~96% .

The acid strength of sulfuric acid is designated as percentage sulfuric acid or degrees Baume (ºBé) (IARC1992).
Degrees Baume is a mathematical relationship with specific gravity (Bé = 145 - (145/specificgravity) ) that is consistent at concentrations below 93.2% sulfuric acid. At higher concentrations, the acid is referred to in terms of percentage sulfuric acid.

So I don't know why they use it here, the chart I have goes up to 65.9°Bé = 95.6% (d=1,759)


  • Guest
« Reply #10 on: October 12, 2003, 08:13:00 PM »
I believe that is degrees Baume.  It refers to the density (and therefore the concentration) of the acid solution.


  • Guest
phenol from salicylic acid
« Reply #11 on: October 14, 2003, 10:46:00 PM »
A note from the hardcore precursor department, found in

Patent US2488472


Salicylic acid is decarboxylated by heating the acid with 1% (by weight of the acid) of Ca(OH)2 at a temperature ranging from 170°C to 185°C until the reaction is complete as evidenced by cessation of evolution of carbon dioxide gas.



  • Guest
something similar
« Reply #12 on: November 24, 2003, 01:53:00 PM »
can be found


(, although their goal is not prepn. of phenol. Ning imagines that without the K2CO3, phenol would be the major product.


  • Guest
« Reply #13 on: August 05, 2004, 10:42:00 AM »
The patent number given in

Post 464301 (missing)

(psyloxy: "improved preparation of nitrosophenol", Novel Discourse)
is in error and should read:

Patent US2234692