Aldehyde ammonia

This reaction consists of the condensation of two molecular equivalents of a 1,3 diketone (or a J3-keto-ester) with one equivalent of an aldehyde and one of ammonia. Thus the interaction of ethyl acetoacetate and acetaldehyde and ammonia affords the 1,4-dihy dro-pyridine derivative (1), which when boiled with dilute nitric acid readily undergoes dehydrogenation and aromatisation" to gb e the diethyl ester of collidine (or 2,4,6-trimethyl-pyridine-3,5 dicarboxylic acid (II)). For the initial condensation the solid aldehyde-ammonia can conveniently be used in place of the separate reagents. 

Required Ethyl acetoacetate, 32 g. (32 ml.) acetaldehyde-ammonia, lO g. Note. The aldehyde-ammonia should preferably be fresh material the quantity should be increased to 15 g. if an old sample, which has formed brown sticky lumps, is employed.)... 

Gently warm a mixture of 32 g. (32 ml.) of ethyl acetoacetate and 10 g. of aldehyde-ammonia in a 400 ml. beaker by direct heating on a gauze, stirring the mixture carefully with a thermometer. As soon as the reaction starts, remove the heating, and replace it when the reaction slackens, but do not allow the temperature of the mixture to exceed 100-no the reaction is rapidly completed. Add to the mixture about twice its volume of 2A -hydrochloric acid, and stir the mass until the deposit either becomes solid or forms a thick paste, according to the quality of the aldehyde-ammonia employed. Decant the aqueous acid layer, repeat the extraction of the deposit with more acid, and again decant the acid, or filter off the deposit if it is solid. Transfer the deposit to a conical flask and recrystallise it twice from ethanol (or methylated spirit) diluted with an equal volume of water. The i,4-dihydro-collidine-3,5-dicarboxylic diethyl ester (I) is obtained as colourless crystals, m.p. 130-131°. Yield 12 5 g,... 

Unlike aliphatic aldehydes (with the exception of formaldehyde which 3delds hexamethylenetetramine. Section 111,67) benzaldehyde yields hydrobenzamide (and not an aldehyde ammonia) with ammonia ... 

Chloral forms well-crystallized adducts (126) with diaziridines containing at least one NH group (B-67MI50800). Carbonyl addition products to formaldehyde or cyclohexanone were also described. Mixtures of aldehydes and ammonia react with unsubstituted diaziridines with formation of a triazolidine ring (128). Fused diaziridines like (128) are always obtained in ring synthesis of diaziridines (127) from aldehyde, ammonia and chloramine. The existence of three stereoisomers of compounds (128) was demonstrated (76JOC3221). Diaziridines form Mannich bases with morpholine and formaldehyde (64JMC626), e.g. (129). 

Syntheses of alkyldiazirines (287) must start from the diazirinotriazolidines (128) formed from an aldehyde, ammonia and (-butyl hypochlorite. Since the three-membered ring in (128) is much more stable towards acids than the five-membered ring (Section 5.08.3.2.2), the diazirines are obtained by acid hydrolysis of compounds (128) in the presence of an oxidant (62CB795). 

The flask is attached to an upright condenser in which the water is kept at a temperature of 30—SS""- Alcohol and aqueous vapour condense in the condcnsei the aldehyde, on the other hand, passes by a tube attached to a roo c c. pipette into two narrow (100 c.c.) cylinders, onc-tlnid filled with the diy ether, and cooled in ice-natei. The aldehyde leadily dissohes in the ether and is lapidly absoibecl. If the etheieal solution is now saturated with diy ammonia gas, the whole of the aldehyde separates out in the form of coloui-less crystals of aldehyde-ammonia,... 

The ether is then decanted from the crystals, wdiich are drained at the filter-pump, w ashed wfith a little ether, and finally diied in (he air on filter-paper. Yield of aldehyde-ammonia, 25—30 grams. It may be used for the reactions described on p. 67. 

Pure aldehyde may be prepared from the aldehyde-ammonia as follows The crystals are dissolved m an equal weight... 

Compound 74 belongs to a special group which forms cyclic aldehyde ammonia 75 (cotarnine) by interaction of the secondary amine group with the aldehyde group. This aldehyde ammonia can be considered to be a pseudo base. 

Heterocyclic enamines A -pyrroline and A -piperideine are the precursors of compounds containing the pyrrolidine or piperidine rings in the molecule. Such compounds and their N-methylated analogs are believed to originate from arginine and lysine (291) by metabolic conversion. Under cellular conditions the proper reaction with an active methylene compound proceeds via an aldehyde ammonia, which is in equilibrium with other possible tautomeric forms. It is necessary to admit the involvement of the corresponding a-ketoacid (12,292) instead of an enamine. The a-ketoacid constitutes an intermediate state in the degradation of an amino acid to an aldehyde. a-Ketoacids or suitably substituted aromatic compounds may function as components in active methylene reactions (Scheme 17). 

The simplest compounds, -pyrroline and -piperideine,donotexistin the monomeric form. Schdpf et al. (29S) described two geometric isomers of J -piperideine trimer and called them a- and -tripiperideines (182). An equilibrium exists between A -piperideine and both trimers which, therefore, react as typical aldehyde ammonia. The trimer rearranges at pH 9-10 in an almost quantitative yield to isotripiperideine (183) which, in turn, is in equilibrium with tetrahydroanabasine (184) and -piperideine. 

In the case of the bases derived from quaternary heterocyclic ammonium salts, the carbinolamines (5) can react as cyclic aldehyde-ammonias with many reagents with which the amino-aldehyde (7) could react. However, reactions of the carbinolamines which are not characteristic of amino-aldehydes are also known. Carbinolamines can easily be reconverted into the quaternary salts by the action of dilute acids, and they form alkyl ethers very easily with alcohols. If these last reactions do not occur, then this is convincing evidence for the base possessing the amino-aldehyde structure. However, if these reactions do occur this does not provide unambiguous confirmation of the carbinolamine structure. They are also given by the bi-molecular ethers (8), and, in the case of a tautomeric equilibrium... 

The rate of iodine formation depends on the degree of A"-substitu-tion. Compounds which are unsubstituted on both the iV-atoms (35) and those wdth a single A -substituent (43) liberate instantly the calculated quantity of iodine in the cold. However, the 1,2-disubstituted diaziridines (44) need brief heating with the acid iodine solution they then give 95-100% of the calculated iodine. " This effect of substitution is so well defined that it can be used for a proof of constitution. The diaziridino-triazolidincs (37) prepared from aldehydes, ammonia, and chloramine give complete iodine liberation only on heating. Thus the structure 57 which is isomeric with 37 can be eliminated. ... 

In the former Soviet Union much use is made of industrial by-products to prepare acid inhibitors. The PB class is obtained by treating technical butyraldehyde with ammonia and polymerising the resulting aldehyde-ammonia. PB-5, for example, with O-Ol-O-15% of an arsenic salt is used in 20-25% HCl. A mixture of urotropine (hexamethyleneimine, hexamine) with potassium iodide, a regulator and a foaming agent is the ChM inhibitor. BA-6 is prepared from the condensation product of hexamine with aniline. A more recent development is the Katapin series which consists of /7-alkyl benzyl pyridine chlorides Katapin A, for example, is the /7-dodecyl compound. 

Reaction between aldehydes, ammonia or amines, and an active... 

Reaction between aldehydes, ammonia, and carboxylic acids or... 

Ammonia itself yields imines, R2C=NH, with carbonyl compounds but these derivatives are unstable and react with each other to form polymers of varying size. The classical aldehyde ammonias are found to be hydrated cyclic trimers, but from aldehydes carrying powerfully electron-withdrawing substituents it is possible to isolate the simple ammonia adduct [73, cf. (72), and hydrates, p. 208, hemi-acetals,... 

Taurine is generally prepared from ox bile1 or the large muscle of the abalone.2 It has been synthesized from isethionic add through chloroethanesulfonic acid followed by the action of aqueous ammonia 3 from ethyleneimine and sulfur dioxide 4 from 2-mercaptothiazoline by oxidation with bromine water 5 from bromoethylamine and ammonium sulfite 6 and from acetaldehyde by a complex set of reactions involving sulfonation, formation of the aldehyde ammonia and the imido sulfonic add and finally reduction.7 The method given in the procedure has recently appeared in the literature.8 9... 

Anthrapyrimidine and its substituted derivatives are obtained by condensation of 1-aminoanthraquinone (or its derivatives) with formamide or aqueous form-aldehyde/ammonia in the presence of an oxidant, such as ammonium vanadate or m-nitrobenzosulfonic acid. A newly developed, more simple route proceeds via formamidinium chloride, which is prepared from 1-aminoanthraquinone with di-methylformamide and thionyl chloride or phosphorus oxychloride. Cyclization in a solvent in the presence of ammonium acetate affords the desired product ... 

Since the acetaldehyde cannot be separated by fractional distillation from the ether in which it has been collected, it is converted into the crystalline aldehyde-ammonia. The contents of the two receivers are transferred to a small filter jar which is cooled in a freezing mixture, and ammonia gas is led in from a cylinder. The delivery tube for the current of ammonia is a straight calcium chloride tube with its wide end deeply submerged in the liquid. To break up the crystalline mass which is formed, this tube is frequently moved to and fro. The jar is kept covered with a clock-glass (bored), piece of cardboard, or copper gauze. On account of the ether which evaporates, all flames in the vicinity must be extinguished. 

Ammonia is passed into the ethereal solution of aldehyde for about thirty times this litre period (determined above), and the mixture is left for one hour for complete crystallisation a sample of the liquid portion is then treated in a test tube with more ammonia gas in order to ascertain whether further precipitation occurs. If this is not so the aldehyde-ammonia is separated at the pump, washed a few times with absolute ether, and dried first on filter paper and then in a non-evacuated desiccator over sulphuric acid. If kept in a well-closed container the dry substance can be preserved for a long time impure material turns brown and decomposes in a few days. Yield 50-60 g. 

To obtain the free aldehyde 25 g. of the aldehyde ammonia are dissolved in 25 c.c. of water, a cooled mixture of water (40 c.c.) and concentrated sulphuric acid (30 c.c.) is added, and the acetaldehyde liberated is distilled from the water bath through a calcium chloride U-tube (gently warmed if the external temperature is low) and through an efficient coil condenser. In order to prevent autoxida-tion of the acetaldehyde the apparatus is filled with carbon dioxide before distillation, and, since the vapour pressure of the aldehyde is high, a slow current of carbon dioxide is passed again, for a short time only, at the end of the distillation. Since acetaldehyde boils at 21° the receiver, which is attached to the condenser by means of a cork stopper, must be well cooled in an ice-salt freezing mixture. 

In from eight to ten hours up to 10 1. of acetylene are taken up. The colourless intermediate mercury compound very soon begins to separate. After the passing in of acetylene has ceased the whole of the reaction mixture is transferred to a round-bottomed flask and heated on a conical (Babo) air bath, while steam is passed through to decompose the mercury compound. The acetaldehyde liberated distils with the steam. An apparatus similar to that described under (a) is used one receiver containing ether and cooled in a freezing mixture is sufficient. The aldehyde is precipitated from the ethereal solution as aldehyde-ammonia in the manner described above. Yield of aldehyde-ammonia 5-6 g. 

Acetaldehyde combines with ammonia to form aldehyde-ammonia, as was shown by the method of preparation described. 

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