Ethyl 4,4,4-trifluoro-2- acetoacetate

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,... 

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

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.

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

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... 

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)... 

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],... 

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