Acetone azine

Bayer ketazine A process for making hydrazine by the reaction of sodium hypochlorite with ammonia in the presence of acetone. Acetone azine is an intermediate. Never commercialized. See also Raschig (1). 

Acetic anhydride, with 2-hep-tanone to give 3-n-butyl-2, 4-pentanedione, 51, 90 ACETIC FORMIC ANHYDRIDE, 50, 1 Acetone azine, 50, 2 ACETONE HYDRAZONE, 50, 2, 28 Acetophenone, 54, 93 as sensitizer for irradiation of bicyclo[2.2.1]hepta-2,5-diene to give quadricyclane,... 

Azine, This term has the following meanings a)Pyridine(Ref 2) b)Sym di-ylidene derivs of hydrazones of ketones or aldehydes, such as acetone azine. (CHj CiN-N CfCHj) (Ref 3) c)The group (Ns)a is called free azine" or nitrine. According to Walden Audrieth (Ref 1), the halides of azine are extremely expl substs which undergo spontaneous de-compn at RT... 

Soviet chemists have used the Diels-Alder reaction of acetone azine (309) with azotrifluoromethane (310) for the preparation of 3,3,6,6-tetramethyl-l,2-bis(trifluoromethyl)-l,2,3,6-tetrahydro-l,2,4,5-tetrazine (311) (62DOK(i42)354>. 

AH90 CeHi2Ng acetone azine 1Y UNNUY acetone aq PY H2S04 0.025 TXIOO - 30 DME/SCE 0-0 -... 

Acetone, AB82 Acetone azine, AH90 Acetone benzoylhydrazone, AR73 Acetone cyanoacetic acid hydra-zone, AH6l... 

The Diels-Alder adduct isolated from the reaction of hexafluoro-acetone azine and 2,3-dimethyl-1,3-butadiene at elevated temperatures [75JCS(P1)1411] in fact is the result of a two-step process, namely of a [3-1-2] cycloaddition reaction and a subsequent [3.2] sigmatropic rearrangement [82JFC( 19)589]. 

A. Acetone azine. In a 500-ml. round-bottomed flask fitted with a mechanical stirrer (Note 1) and dropping funnel is placed 145 g. (183 ml., 2.5 moles) of acetone (Note 2). The flask is cooled in an ice bath and, with vigorous stirring, 65.5 g. (1.31 moles) of 100% hydrazine hydrate (Note 2) is added at such a rate that the temperature is maintained below 35° by the ice bath. The addition takes 20-30 minutes. The mixture is stirred for an additional 10-15 minutes, and then 50 g. of potassium hydroxide pellets is added with vigorous stirring and continued cooling (Note 3). The upper liquid layer is separated and allowed to stand over 25 g. of potassium hydroxide pellets for 30 minutes with occasional swirling (Note 4). After filtration, the liquid is further dried with two successive 12.5-g. portions of potassium... 

A mixture of 112 g. (1.0 mole) of acetone azine and 32 g. (1.0 mole) of anhydrous hydrazine is placed in a 300-ml. round-bottomed flask fitted with a reflux air condenser and drying tube, and kept at 100° for 12-16 hours. (Caution This reaction and the subsequent distillation should be carried out behind a protective screen.) The crude product is then rapidly distilled through a water-cooled condenser and the colorless fraction boiling at 122-126° collected, n22D 1.4607 (Note 7). It weighs 111-127 g. (77-88%, Notes 7 and 8) and is essentially pure acetone hydra-zone (Note 9). 

The distillation gives a small forerun, b.p. 120-128°, containing hydrazine and acetone hydrazone. There is virtually no distillation residue. The submitters carried out the preparation of both acetone azine and acetone hydrazone on a fourfold scale with comparable results. 

The forerun contains hydrazine. Material boiling above 126° contains much acetone azine. With a slow rate of distillation, disproportionation occurs and the yield of acetone hydrazone is reduced. If the forerun and material boiling above 126° are combined and reheated at 100° for 12-16 hours, they give more acetone hydrazone on redistillation. With further repetitions of this procedure, the yield is almost quantitative. 

The hydrazone should be used as soon as possible. If it is stored, care must be taken to exclude moisture, which catalyzes disproportionation to hydrazine and acetone azine.5 7 Even in the absence of moisture it disproportionates slowly at room temperature and so should be redistilled immediately before use. Old samples can be regenerated fairly satisfactorily by reheating them for 12-16 hours at 100° before redistillation, but there is always some irreversible decomposition to high-boiling products during storage. 

The procedure for acetone azine is essentially that of Curtius and Thun.5 The method for acetone hydrazone is adapted from that of Staudinger and Gaule.8 The hydrazone has been prepared directly from acetone and hydrazine, but this is much less satisfactory.6... 

The solution is ca. 2 M. Yields were determined by nitrogen evolution on adding acetic acid, or spectrometrically from the visible absorption band at 500 m fi, which has e 2 as calculated from the nitrogen evolution. Yields estimated by addition of a standard solution of benzoic acid and titration with alkali were consistently much lower. Both methods underestimate the yield, since decomposition with acid gives tetramethyl-ethylene and some acetone azine in addition to the isopropyl ester.3 The nitrogen evolution method (and therefore the spectrometric method) probably underestimates the yield by ca. 10-20%, the titration method by more than 50%. 

This hydrazine is available by catalytic reduction of acetone azine. ... 

P-D-XylopyranosyI)-L-serine 16. To a solution of 0-benzoyl protected xylosyl serine (0.23 g, 0.4 mmol) in methanol (20 mL) is added at room temperature hydrazine hydrate (100%, 20 mL). Monitoring by TLC (ethyl acetate-methanol-water 13 5 2.4) proves the reaction to be complete within 30 min. After 40 min, acetone (50 mL) is added to transform the hydrazine to the acetone azine (which is volatile). After stirring for 1 h, the solution is concentrated in vacuo, the residue is stirred with ethyl acetate to extract impurities and give a pure product yield, 80 mg (86%), mp 215°-218°C (decomposition) reported [39] 230°-235°C, [a] -49.8° (c 0.3, HjO), reported [39] [a] -12° (c 1.0, H O). 

Sodium hypochlorite solution (ca. 1.5 mol/L), ammonia and acetone in a molar ratio of 1 15 to 20 2 are reacted together at 35°C. A solution results consisting of 5 to 7% by weight of acetone azine together with sodium chloride and excess ammonia. This ammonia is distilled off and returned to the reaction. Next, the acetone azine-water-azeotrope (b.p. 95°C) is distilled off leaving the sodium chloride solution. Herein lies the essential difference from the Raschig process in which the hydrazine water mixture has to be separated from solid sodium chloride. 

Finally, the acetone azine is hydrolyzed with water in a reaction distillation tower into acetone (head product) and a 10% aqueous hydrazine solution (sump product) at temperatures up to 180°C and pressures of 8 to 12 bar. The hydrazine solution is concentrated to its azeotrope composition of 64% by weight of hydrazine. The hydrazine yield is 80 to 90%, based on the hypochlorite utilized. 

This hydrazine is available by catalytic reduction of acetone azine.1 Protection of carboxylic acids.2 The reagent reacts with carboxylic acid derivatives (the acyl chloride or mixed anhydride) to give a monoacylhydrazide, RCON(CHMe2)-NH(CHMe2). The derivatives are stable to both acids and bases. They are reconverted into carboxylic acids by selective oxidation, preferably with lead tetraacetate. The new method of protection has been used for penicillins. 

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