Ethyl a-methylacetoacetate

Similar investigations were reported by this group using /S-oxoesters as the precursors to be aminated products in the presence of CaO and 3n as amination reagent . Ethyl acetoacetate gave a-monoaminated and a-bisaminated products (Scheme 35) depending on the substrate base ratio. An A-aminated product was also obtained in the amination of ethyl a-methylacetoacetate. 

In the recent patent literature a procedure is given for coupling a diazonium salt with ethyl a-methylacetoacetate to afford an azo compound which could be used as an acetylating agent because its acetyl group was readily cleaved under mild conditions [26], In the coupling reaction, relatively weak bases such as pyridine, picolines, quinoline, and collidine are said to be effective. The example is given here for illustration only. It is to be noted that this is a composition of matter patent. 

Dicarbonyl compounds such as ethyl a-methylacetoacetate (54) can be efficiently alkylated in good yields with vinyl ethers in the presence of Cu2+ and Mn3+ as shown in... 

Edwards and Matsumoto (151) have synthesized these acids by the Reformatsky reaction using ethyl a-methylacetoacetate and ethyl... 

Carbonyl reduction. Many substrates have been reduced enantioselectively to give alcohols trifluoromethyl ketones, a-acetoxyketones, pyridinophenones, ethyl a-methylacetoacetate, a-keto acid derivatives," and 3-chloro-2-oxoaIkanoic esters a,/3-Epoxy ketones undergo reduction and hydrolytic ring opening/... 

Ethyl a-methylacetoacetate added at ca. 50° with stirring to a soln. of K in ferf-butanol, then trichloroacrylonitrile dropped in rapidly with ice-cooling,... 

Hydroxy-2-methyl-4//-pyrido[l,2-n]pyrimidin-4-one was prepared in the reaction of 2-amino-3-benzyloxypyridine and ethyl acetoacetate at 60 °C, then at 100 °C for 3 h in 22% yield (96MIP1). Reaction of 2-amino-3-hydroxypyridine and ethyl 2-methylacetoacetate in a 1 2 mixture of... 

In our previous research, we found that the antialgal allelochemical Ethyl 2-Methylacetoacetate (EMA) caused loss of cell membrane integrity. It hinted that EMA may cause a change in the membrane. It is reported that environmental stress may increase the concentration of ROS in plant cell. The excessive ROS may cause a decrease of antioxidation enzymes activity and lipid peroxidation. The effect of EMA on the activity of SOD and POD and lipid fatty acids of Chlorella pyrenoidosa, Chlorella vulagaris and Microcystis aeruginosa were evaluated to elucidate the mode of action of EMA. 

Ethyl orthoacetate, 48 Ethyl orthobenzoate, 54 Ethyl orthobromoacetate, 60 Ethyl orthodibromoacetate, 60 Ethyl orthoformate, 50 Ethyl orthothioformate, 50 Ethyl a-phenylazo-a-methylacetoacetate, 299... 

Although other condensation reactions with 4-aminopyridine are reported to fail, they have in most cases succeeded with 4-aminoquinoline.59 Dey and Joullie87 have prepared a series of trifluoro-methylbenzo[A]-l,6-naphthyridines by condensing ethyl trifluoro-methylacetoacetate with 4-aminoquinaldine. 

Earlier reported syntheses have been shown to give isoxazolin-5-ones. Other isoxazolin-3-ones have been prepared by the reaction of methylacetoacetic esters and hydroxylamine. An additional synthesis was reported by the action at 0°C of hydroxylamine on ethyl a-benzoylpropionate to produce an insoluble hydroxamic acid which cyclized on acid treatment. The hydroxamic acid acetal was similarly transformed into the isoxazolin-3-one (Scheme 149) (71BSF3664, 70BSF1978). 

In 1887, in an attempt to prepare the azo ester 4 by coupling benzenediazonium chloride 2 with ethyl 2-methylacetoacetate 1, Japp and Klingemann obtained a product which was recognized as the phenylhydrazone of ethyl pyruvate 3.1"4... 

To a 1 1.5 molar ratio mixture of resorcinol (starting with 8 mmol) and ethyl 2-methylacetoacetate at 0°C was added an excess amount of 98% H2SO4 over 1 h. Then the mixture was stirred at room temperature until the reaction was complete as monitored by TLC ( 16 h). The mixture was poured into ice water and allowed to stand overnight. The precipitated solid was filtered, washed with water until neutral, and dried in vacuo to afford 87% 3,4-dimethyl-7-hydroxycoumarin, which formed colorless crystals from EtOH, m.p., 220°C dec. 

Table 15.2 Enantioselective Mannich reaction of ethyl 2-methylacetoacetate with N-tosyl-a-imino methyl ester catalyzed by Pr-trisox/Cu(CI04)2 or Pr-B0X/Cu(CI04)2 [24a].

As test reactions, the a-hydrazination of ethyl 2 methylacetoacetate and the Henry reaction of nitromethane and 2-nitrobenzaldehyde were chosen. In both cases, a significant difference between the bis-oxazoline (BOX) and trisox-based catalysts was notable. The performance of all the trisox-based catalysts proved to be inferior for both reactions, both in terms of the activities and enantio-selectivities. While the attachment of a linker at the ligand backbone and the immobilization only moderately affected the BOX-based catalysts for both reactions, the effect on the trisox-based catalysts led to a dramatic decrease in activity. 

There are some other synthetic methods to obtain fluorine-containing quinolines which are based on using of fluorinated anilines with a free ortfe>-position and three-carbon reagents. Forinstance, 8-fluoro-2,3,6-trialkyl substituted4-hydroxyquinohnes 15 were synthesized by the reaction of 13 with ethyl 2-methylacetoacetate and cycUzation of the obtained enamines 14 into 8-flnoroquinolines 15 (Scheme 5) [10]. 

Methyl Ethyl Ketone. 1 mole (20 g) of methylacetoacetic ester are refluxed with 250 cc of baryta water (saturated) until the oily layer disappears. Distill on a water bath to 90°. Stir violently or shake for three hours with a saturated solution of sodium bisulfate, and collect the crystals and distill with an excess of dilute sulfuric acid at 90°. The distillate is dried over calcium chloride and distilled again, retaining the fraction at 79-82°. Yield 70% theoretical (7 g). 

Nitrosohydroxylamino)-1-propanoic Acid or a-lsonitraminopropionic Acid a-[Nitroso-hydroxylamino] -propionsaure or a-Isonitra-mino-propionsaure HO.N(NO).CH(CH3 ).COOH mw 134.09, N 20.89%. It is stable only in solns. May be prepd by warming with soda the crude soln obtained by the action of nitric oxide on ethylic methylacetoacetate, until the alcohol is driven off the acid is then precipitated as the Lead Salt, PbC3H4N204, which is explosive Refs 1) Beil 4, 576 2) W. Traube, Ber 28,... 

Ethyl thallio(I)methylacetoacetate allowed to react at room temp, with a suspension of the startg. thiophanium bromide in dimethylformamide product. Y almost 100%. D. G. Martin, L. J. Hanka, and L. M. Reineke, Tetrah. Let. 1971, 3791. 

The catalytic reaction of buta-1,3-diene with ethyl methylacetoacetate in the presence of [Pd(T)2-buta-l,3-diene) R2P(CH2)nPR2 l complexes has been investigated . The product was found to be a mixture of 1 1 adducts and the reaction to be fastest when n=2 and R = Pr in dichloromethane as the solvent. The X-ray crystal structure of a side product [ ( H n -CgHi2)Pd 2 Me2P(CH2)2PMe2 ] (42), formed by dimerisation of the butadiene ligand, has been determined. 

The German cockroach (Blattella germanica) uses the doubly branched methyl ketones (603, Scheme 101) and (615, Scheme 102) as sex pheromones. A number of syntheses of (603) have proceeded via bromide (600) or an analog unsaturated at the methyl branch. The branched methyl ketone moiety was introduced by alkylation of ethyl (260) or benzyl 2-methylacetoacetate (261) or of the lithium salt of (2-oxo-butylidene)triphenyl phosphorane (262). Rosenblum et al. (263) coupled... 

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