Acetone hydrazone derivative

The hydrazinium nicotinate group on these reagents commonly is protected against reaction with the active ester by the addition of acetone to form the acetone hydrazone derivative. This hydrazone protective group is readily reversible at neutral or mildly acidic pH and will immediately exchange with a benzaldehyde on the corresponding chemoselective partner to form a stable hydrazone linkage. 

Homocuprates like (58) were used by Heathcock in the course of a total synthesis of lycopodine. In this case, the cuprate derived from acetone dimethylhydrazone (63) was added to the cyano enone (64). In this example, the hydrazone-derived azaallylcuprate was about as effective as lithium dimethylallylcu-prate addition followed by ozonolysis, and gave a lower overall yield than the Sakurai method using methallyltrimethylsilane and titanium tetrachloride. The product (65) was formed as a mixture of isomers (equation 28). 

The half wave potential (E1/2 versus standard calomel electrode) of the acetone derivative of phenelzine was reported (7) as -1.33V in pH 5.9 phosphate buffer (0.1 M KH2PO1, Na2HPO 2H2O) employing a 0.01% gelatin solution as a maximum suppressor. The diffusion current constant (I ) was approximately 2.5. Four electrons were transferred for the reduction of the hydrazone derivative. Waveheight was proportional to concentration in the range of 2.5 x 10 to 2.5 X 10 M in pH 5.9 phosphate buffer. 

Mercaptobenzoylhydrazones of aryl aldehydes, 2-HS-QH4-CONHN=CH-C6H4-X (X=3- or 4-substituent), exist as EtZ isomers in DMSO and also tautomerize to cyclic benzo-l,3,4-thiadiazepines logXj correlates with A method for asymmetric a,a-bisalkylation of a ketone having both a- and protons has been described. For the example of acetone, a chiral A-amino cyclic carbonate hydrazone derivative (45) is treated sequentially with two alkylating agents ... 

Some monosubstituted acetone hydrazones 190 react with phenylcarbonyl isothiocyanate to give the oxatriazepine derivatives 191... 

Although the addition of hydrazine and its derivatives to acetylenic ketones has been studied in considerable detail, their interaction with hydrazones and mono-alkylhydrazones is less well known. Yandovskii and Klindukhova (74ZOR730) have studied the reaction between hydrazones and alkylhydrazones of aliphatic ketones with dipropynylketones and showed that hydrazones of acetone, methyl-ethylketone, and cyclohexane easily add to one of the triple bonds of dipropynylketone to form 4-methyl-1,1,3-trialkyl-2,3-diaza-l,4-nonadien-7-yn-6-ones (yields... 

Figure 1.110 The reaction of SANH with an amine-containing molecule results in an amide bond derivative that terminates in a protected hydrazine group. Reaction with an aldehyde-containing molecule results in release of the acetone-protecting group and formation of a stable hydrazone bond.

Alkyl- and aryl-hydrazones of aldehydes and ketones readily peroxidise in solution and rearrange to azo hydroperoxides [1], some of which are explosively unstable [2], Dry samples of the p-bromo- and p-fluoro-hydroperoxybenzylazobenzenes, prepared by oxygenation of benzene solutions of the phenylhydrazones, exploded while on filter paper in the dark, initiated by vibration of the table or tapping the paper. Samples were later stored moist with benzene at —60°C to prevent explosion [3], A series of a-phenylazo hydroperoxides derived from the phenyl-or p-bromophcnyl-hydrazones of acetone, acetophenone or cyclohexanone, and useful for epoxidation of alkenes, are all explosive [4], The stability of several substituted phenylazo hydroperoxides was found to be strongly controlled by novel substituent effects [5],... 

Functional modifiers are used in binary nomenclature to name anhydrides, e.g. acetic anhydride for (CH3-C0)20, and derivatives of ketones and aldehydes such as oximes, hydrazones and semicarbazones, e.g. acetone oxime for (CH3)2C=NOH. 

An interesting case of the addition of ketone hydrazone is observed in the reaction of acetone dimethylhydrazone with DMAD, wherein the initial nucleophilic attack is through the imino nitrogen, leading to products such as dimethyl A-isopropylidine-lV-dimethylamino-2-aminomaleate (132) and the dihydropyridine derivative (133). A small amount of the dimethylhydrazone of oxaloacetic ester (134) has also been observed in this reaction (Scheme 20). ... 

The carbonyl ylide precursor can be generated by lead tetraacetate oxidation of the hydrazone 58. Thermolysis of 59 in the presence of perdeuterated acetone led to a variety of products, some of which are shown above. An internal quench of the ylide via a 1,4-proton migration led to enol ether 61, while cycloaddition with perdeuterated acetone formed the dioxolane 62 and its regioisomer. Interestingly, the presence of products such as acetone and propene-t/s are proposed to indicate a reversible fragmentation of the ylide to a carbonyl derivative and a carbene. 

Similar reactions occur with other amines, particularly hydrazine, NH2NH2, and its derivatives which form good stable crystalline imines known as hydrazones. hat compound would be formed from hydrazine and acetone ... 

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... 

The (R)-enantiomer of (242) has also been prepared and used as a chiral auxiliary in an enantioselective aldol synthesis of (+)-(S )-gingerol (79CB3703). (R )-Glutamic acid (246) was thus converted into (i )-pyroglutamic acid by simply heating in water. Conversion of (247) to its methyl ester and LAH reduction delivered alcohol (248). Ethyl nitrite treatment of (248) gave nitrosoamine (249), which was methylated to furnish (250). Exposure of (250) to LAH completed the synthesis of the required chiral auxiliary RAMP [(R)- l-amino-2-(methoxymethyl)pyrrolidine]. The hydrazone (252), derived from RAMP and acetone, was... 

The reaction of the nickel(II) perchlorate complex (89) with acetone and related ketones yields simple hydrazone complexes rather than macrocyclic complexes resulting from a Curtis-type reaction. Acetylacetone also fails to bridge the bis(hydrazine) and instead yields a pyrazole derivative (Scheme 37).197 198 In contrast to this result, 1,4-dihydrazinophthalazine undergoes a template reaction with 2,2-dimethoxypropane, a source of acetone, in the presence of nickel(II) fluoroborate and a trace of fluoroboric acid (Scheme 38).199... 

Cleavage of hydrazones, oximes, and semicarbazones. Amberlyst 15, an ion-exchange resin with sulfonic acid groups, is a superior reagent for exchange of nitrogeneous derivatives of carbonyl compounds with acetone. Yields are 85-95% with reactions that proceed at room temperature.1... 

Recent work on the thermal indolization of arylhydrazones has introduced new synthetic possibilities for azaindoles. Kelly et al. refluxed cyclohexanone and deoxybenzoin 2-pyridylhydrazones in diethylene glycol to give 5,6,7,8-tetrahydro-a-carboline (42, R = H) and 2,3-diphenyl-7-azaindole in 70 and 56% yields, respectively, compared with 53 and 12% reported earlier. Similarly, y-carboline 29 was obtained in 95 % yield from cyclohexanone 4-pyTidylhydrazone (lit. 48% ). Several 7-azaindole derivatives were prepared in the same manner. The yields ranged from 5 % for azaindolenine (31) to 88% for 3-phenyl-7-azaindole. 3,3-Dimethyl-7-azaindolenine was obtained in 47 % yield from the isobutyralaldehyde hydrazone. The novel cyclic compounds 40 and 41 were obtained from the 2-pyridylhydrazones of cyclopentanone, a-indanone, and a-tetralone in 67, 95, and 77% yields, respectively. Unfortunately, all attempts to cyclize the acetone, pyruvic acid, and ethyl pyruvate hydrazones were unsuccessful. Also, cyclohexanone and methyl ethyl ketone 5-nitro-2-... 

Annelation, The Gilman ate reagents derived from acetone N,N-dimethyl-hydrazone, either the homocuprate derivative (7, 149) or the more recently developed phenylthio heterocuprate derivative, add in a conjugate fashion to ethyl 1-cyclohexene-1-carboxylate (1) to afford the keto ester (2, 60-70% yield) after hydrolysis of the N,N-dimethylhydrazone group. The keto ester 2 serves as a versatile intermediate tor the preparation of several complementary annelation products 4-8. 

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