Ethyl Benzoyl Acetate

Although phenols have not participated in the Conrad-Limpach reaction under certain conditions thiophenols were not as innocent. Lee and coworkers reported mixtures of thiochromenones and quinolones from reactions of amino-thiophenols with ethyl benzoyl acetate. Amino-thiophenol 67 reacted with ethyl benzoylacetate 68 in PPA to give a mixture of thiochromenone 70 and quinolone 69 in which the quinolone predominated. 

The mercaptals obtained by the acid catalyzed reaction of J3-ketoesters, e.g., ethyl acetoacetate, with methyl thioglycolate (73) undergo the Dieckmann cyclization with alcoholic potassium hydroxide at lower temperatures to give ethyl 3-hydroxy-5-methyl-2-thiophenecarboxylate (74) in 75% yield. ° Besides ethyl acetoacetate, ethyl a-ethylacetoacetate, ethyl benzoyl acetate, and ethyl cyclopentanonecarboxylate were also used in this reaction/ It is claimed that /8-diketones, hydroxy- or alkoxy-methyleneketones, or /8-ketoaldehyde acetals also can be used in this reaction. From acetylacetone and thioglycolic acid, 3,5-dimethyl-2-thiophenecarboxyl-ic acid is obtained. ... 

The condensation of arylsulfonyl acetonitriles 369a-c with 22a proceeds via addition of the in-situ formed anion 370 to the arylsulfonyl acetonitriles 369 to afford the dimers 371, in 69-94% yield, and hexamethyldisiloxane 7 [136]. Furthermore, y9-dicarbonyl compounds such as ethyl acetoacetate 372 a or ethyl benzoyl-acetate 372b are O-silylated by 22 a or 22 c to rather stable alkyl 3-O-trimethylsilyl-oxycrotonoate 373a and alkyl 3-0-trimethylsilyloxy-3-phenyl acrylate 373b [130]. Aliphatic nitro compounds such as nitromethane are O-trimethylsilylated and further transformed into oligomers [132] (cf Section 7.6) and are thus unsuitable reactants for silylation-C-substitutions (Scheme 4.50). 

Highest yields are obtained when the reaction is carried out in boiling toluene until all water and ethanol are eliminated by azeotropic distillation. Other /S-ketocarboxylic esters such as ethyl benzoyl acetate, o-methoxybenzoyl acetate and ethyl acetonedicarboxylate react similarly with aromatic amidoximes (50). 

By reacting 2-amino-3,4,5,6-tetrahydropyridine (118) with ethyl aceto-acetate or ethyl benzoyl acetate in pyridine, Wamhofif and Lichtenthaler178 obtained 1 4 equilibrium mixtures of the tautomers 119 and 120. 

Amide formation, from a carboxylic acid and urea, 37, 50 from 2 ammo 5 nitroamsole and ethyl benzoylacetate, 37, 4 from aniline and ethyl benzoyl acetate, 37, 3... 

Ethoxyquin, 23 Ethyl Acetoacetate, 72 Ethyl Benzoyl Acetate, 72 Ethyl-(E)-2-butenoate, 72 Ethyl-fraras -2-butenoate, 72 Ethyl Crotonate, 72 Ethylene Brassylate, 72... 

Ethyl Acrylate, 486, 686 Ethyl Alcohol, 136, 849 Ethyl Alcohol, 136 Ethyl o-Aminobenzoate, 486 Ethylp-Anisate, 486, 686 Ethyl Anthranilate, 486, 687 Ethyl Benzoate, 486, 655 Ethyl Benzoyl Acetate, 486, (S3)72 Ethyl-(E)-2-butenoate, 486, (S3)72 Ethyl-fraraj -2-butenoate, 486, (S3)72 Ethyl Butyl Ketone, 502 Ethyl Butyraldehyde, (Sl)72... 

I, Br 11 diethyl malonate, ethyl acetoacetate, ethyl benzoyl acetate Cul, CS2CO3 DMSO, 40-50°C [67]... 

CuI/L-proUne (LI) was proved to be a quite efficient catalytic system for this coupling. The reaction proceeded smoothly in DMSO at 40-50°C in the presence of CS2CO3 (Table 9.14, entry 1) [67]. Both aryl iodides and bromides were suitable substrates. A wide range of activated methylene compounds, including ethyl ace-toacetate, ethyl benzoyl acetate, and diethyl malonate were compatible with these reaction conditions. This catalytic system could also be used for the arylation of aryl iodides with acetylacetone and ethyl cyanoacetate (entry 2) [68]. Recently, it was found that 2-picoUnic acid (L4) could lead to the arylation of aryl iodides and diethyl malonate worked at room temperature (entry 3) [69]. For hindered substrates or aryl bromides, higher reaction temperatures were still required. Additionally, Chxn-Py-Al (L16) was revealed to accelerate the Cul-catalyzed coupling of iodobenzene with diethyl malonate, ethyl cyanoacetate and malononitrile (entry 4) [26],... 

A mixture of 384 mg ethyl benzoyl acetate (2 mmol) and 126 mg phloroglucinol (1 mmol) was irradiated with microwaves (ETHOS D, Millestone, at 80% of a total output of 1000 W or with the temperature control set to 240°C) for 3 min. The crude product was dissolved in 20 mL 10% aqueous NaOH and washed with diethyl ether (2 x 20 niL) the product was precipitated by adding concentrated HCl. The product was filtered, washed with water, and vacuum dried to give 243 mg chrysin, in a yield of 96%. Pure chrysin can be obtained by crystallization from dichloromethane-methanol, m.p. 288-290°C. 

Oxobenz (de) anthracene. See Benzanthrone P-Oxobenzenepropanoic acid ethyl ester. See Ethyl benzoyl acetate 2-Oxo-1,2-benzopyran. SeeCoumarin 2-Oxobornane. See Camphor a-(2-Oxoborn-3-ylidene) toluene-4 sulfonic acid. See Benzylidene camphor sulfonic acid... 

Yamazaki, Y, Miyagawa, X, and Hasegawa, X, Photocychsation of (alkylthio)ethyl benzoyl acetates via remote proton transfer fohowing charge transfer interaction between excited ketone carbonyl and thioether chromophore, /. Chem. Soc., Perkin Trans.l, 2971, 1997. 

---