Cyclohexanone reaction with hydrazine

Formation of a 1,2-disubstituted hydrazine by acid hydrolysis of an appropriately substituted pyrazolidine has been noted (67HC(22)l), but the most interesting ring fission of pyrazolidines involves the N(l)—N(2) bond of 1-phenylpyrazolidines (421). If, instead of phenylhydrazone, compound (421) is used in the Fischer indole synthesis, N- aminopropylin-doles are formed (73T4045). Scheme 39 shows the reaction with cyclohexanone. 

The fixed geometry of a, 3-unsaturated ketones in the S-cis form, as observed in arylidene alkanones, influences their reactivity. For example, the reaction of arylhydrazines with 3,5-diarylidene-4-piperidones, 2-arylidene-l-tetralones, 2,6-diarylidenecyclohexanones and 2-arylideneindan-l,3-diones requires stronger conditions than for the case of their noncyclic analogues [76, 77, 78, 79, 80, 81, 82, 83, 84]. However, arylidene derivatives of cyclohexanone, 1-indanone, 4-chromanone, 4-thiochromanone and TV-methyl-4-piperidone hydrochloride react with hydrazines more easily [85,86,87,88], It is interesting to note that the more complicated and sterically hindered unsaturated ketones of the spiro type 64 react with hydrazine and phenylhydrazine very easily in the presence of piperidine, leading to pyrazoles 65 in high yields [89] (Scheme 2.16). 

Using Table 9.1 as a guide, write an equation for the reaction of hydrazine with cyclohexanone. 

Secondary amines reacted to form hydrazines in yields of 90% and better. Aniline can be converted to phenylhydrazine. Sometimes the addition was followed by the elimination of water rather than the aminated nucleophile. For example, treatment of 3,3-pentamethyleneoxaziridine with methoxide ion produced cyclohexanone oxime (9-methyl ether. Formanilide reacted with 3-phenyloxaziridine in the presence of sodium ethoxide to produce benzaldehyde phenyUiydrazone. " Of considerable interest is the reaction of Schiff bases with these oxaziridines to produce diaziridines. Other examples are given in Schmitz recent review. One intramolecular version of this kind of amination is known oxaziridine 57 was converted to benzophenone and 5,6-dihydro-4H-l, 2-thiazine 58 upon heating. ... 

The reaction of cyclohexanone with sodium cyanide and hydrazine sulfate in aqueous solution involves production in situ of both hydrogen cyanide and hydrazine. ... 

Freshly sublimed AICI3 (134 g, 1 mol) was added to -BuPyCl (50 g, 0.5 mol) at r.t. under N2 to provide the chloroaluminate ionic liquid. A mixture of phenyl hydrazine (0.9 g, 8.3 mmol) and cyclohexanone (0.8 g, 8.3 mmol) was added dropwise to ionic liquid (1.5 mL, 6.5 mmol), at 180-185 °C for 3 h under efficient stirring under N2. After the reaction was complete (monitored by TLC), it was quenched with water/conc. HCl, extracted Et20, and the Et20 solution was passed through anhyd. Na2S04. The Et20 was removed to obtain the desired product, which was purified by recrystallization (EtOH) (92% yield). 

Borsche—Drechsel Cyclization Reaction of Cyclohexanone with (2,5-Dimethyl-4-Nitrophenyl)Hydrazine to Provide 1,4-Dimethyl-3-Nitro-9H-Carbazole ... 

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