Acetoacetate, Trifluoro

Trifluoro acetoacetic ester 52 reacts with 30 yielding mixtures of ami-nodihydropyran 53 and piperidone 54 (06T2255) (Scheme 6). 

There have been some further examples of the use of the Conrad-Limpach reaction on substituted 5-aminoquinolines for the synthesis of 4-hydroxy-1,7-phenanthrolines, although the products (see Section IV,F,1) should properly be designated as phenanthrolinones.169 Hot diphenyl ether is often employed as the medium for ring closure.170 Ethyl trifluoro-acetoacetate has been used successfully in place of ethyl aceto-acetate, and this variation has allowed entry to 2-trifluoromethyl-substituted 1,7-phenanthrolines.96 Extensions of the Conrad-Limpach type of synthesis starting with m-phenylenediamine (20) and utilizing diethyl ethoxymethylene malonate or ethyl ethoxalylacetate, reagents frequently used in quinoline syntheses, have afforded, after hydrolysis,... 

In this section, for the reasons outlined above (Fig. 3.1) and with the purpose of exemplification, three model xenobiotics are considered ethyl acetoacetate (compound 1), ethyl 4-chloro-acetoacetate (2), and ethyl 4,4,4-trifluoro-acetoacetate (3), the structures of which are given in Fig. 3.3. 

Fig. 3.48 Stereoselective reduction of (R)-ethyl-4,4,4-trifluoro-acetoacetate by aldehyde reductase.

A. Ethyl 4,4,4-trifluoro-2-(trlphenylphosphoranylidene)acetoacetate. A 2-L, four-necked, round-bottomed flask is equipped with a nitrogen line attached to a bubbier, a 250-mL pressure-equalizing funnel, an overhead stirrer and a thermometer. The flask Is charged with 215 g (0.5 mol) of (carbethoxymethyl)triphenylphosphonium bromide and 1.1 L of anhydrous tetrahydrofuran (THF) (Notes 1 and 2). The stirred suspension is cooled in an ice water bath and treated with 150 mL (1.1 mol) of triethylamine (Note 3) added dropwise over 5 min. After the mixture is stirred for an additional 30 min at 5°C, it is treated dropwise with 78 mL (116 g, 0.55 mol) of trifluoroacetic anhydride (Note 4) in such a manner that the reaction temperature is... 

The conversion of 5,5,5-trifluoro-4-trifluoromethylpent-3-en-2-one with methyl acetoacetate in the presence of sodium hydride opens a new reaction pathway for the preparation of molecules which might show some biological and medical activities. The first step of this reaction is the anti-Michael addition of the nucleophile (a-metallated ester) to the 3-position of 5,5,5-trifluoro-4-trifluoromethylpent-3-en-2-one. In the next step metallation in the /-position yields the enolate which attacks nucleophilically the olefinic CF2-carbon forming 4-acetyl-2-fluoro-6-methyl-5-methoxy-carbonyl-3-trifluoromethylpyran by fluoride elimination. 

Ethyl acetoacetate was acylated with 3,4,5-trifluoro-2,6-dimethoxybenzoyl chloride to give ethyl 3-oxo-2(3,4,5-trifluoro-2,6-dimethoxybenzoyl)butyrate (01IZV1090), preparated as in (01MC76). The compound was used for the synthesis of 6,7,8-trifluoro-5-hydroxy-2-methylchromone (Scheme 168). 

Ethyl 4,4,4-trifluoro-2-(triphenylphosphoranylidene)acetoacetate Butanoic acid, 4,4,4-trifluoro-3-oxo-2-(triphenylphosphoranylidene)-, ethyl ester (11) (83961-56-2) (Carbethoxymethyl)triphenylphosphonium bromide Phosphonium, (carboxymethyt)triphenyl-, bromide, ethyl ester (8) Phosphonium, (2-ethoxy-2-oxoethyl)triphenyl-, bromide (9) (1530-45-6)... 

Trifluormethylated furans (35) are available via iodolactonization of y-substituted ethyl trifluoro-acetoacetates tetrahydrofurans are intermediates in this reaction (Scheme 34) <93JCS(Pl)2787>. 

Isomeric furans 110-112 were obtained by reaction of 103 or ethyl acetoacetate 108 with l,l,l-trifluoro-3-bromoacetone 109 [87, 88], Reaction of 109 with 2,6-diaminopyrimidin-4-one 113 produced bicyclic adduct 114 aromatization of which gave furo[2,3-d]pyrimidine 115 [89, 90],... 

Cyanidiutn caldarlum) reduced aromatic ketones. Plant cell cultures (Nicotiana tabacum var. Samsun NN cells) reduced t-butyl acetoacetate to the corresponding (S)-alcohol with high optical yield. Radish (Raphanus sativus L.) sprout reduced a, a, a-trifluoro-acetophenone and Arabidopsis seedlings sprout reduced f-butyl acetoacetate to the corresponding chiral alcohol in eantiomeric excess. 

C6H7F3O3 4,4,4-trifluoro-acetoacetic acid ethyl ester 372-31-6 ... 

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