3.5- dioxo-6-ethyl-2-methyl

The reactions of 4,6-dioxo-2-methyl-2-(4-nitrophenyl)-l, 3-dioxane (441, R1 = Me, R2 = 4-N02Ph), ethyl orthoformate, and anilines in boiling acetic acid for 5 min gave arylaminomethylenemalonates (442, R = aryl, R1 = Me, R2 = 4-N02Ph) in 65-70% yields [78ZN(B)I550]. 

Telluran [2-(2,5-Dioxo-tetrahydro-imidazol-4-yl)-ethyl]-methyl-E12b, 393 [(H3C)2Te2 + Na-R] Tellurinane 3,5-Bis-[hydroximino]-2-methyl- E12b, 450 (Oxo ->Oxim)... 

Amino-2,4-dioxo-l-methyl-5-propylamino-l,2,3,4-tetrahydro-E15/3, 2766 (Br - NH-R) Sydnon 4-Ethyl-3-(2-methyl-propyl)-E8c, 401 (5-NO-imino - 5-Oxo)... 

Aza-bicyclo[3.2.1 oct-2-en 2-Carboxy-8-methyl- V/Id, 394 Bicyclo[2.2.1 hepten 5,6-Dimethyl-5-nitro- X/l, 397f. 5-Ethyl-5-nitro- X/l, 397f. Cyclobuten 2-Diethylamino-3,4-dioxo-1-methyl-E15/2. 1427 (F/Cl -> Oxo)... 

Acetyl-ethyl-aminol-2,4-dioxo-l-methyl-l,2,3,4-tetrahydro- E15/3, 2786 (NH - N-CO-R)... 

Cyclohexan 1,3-Dioxo-2-methyl-2-(1-methyl-1-nitro-ethyl)- E19a, 746 (Dion A Nitro-alkan) Cyclopentan 2-Acetyl-2-(1-methyl-l-nitro-ethyl)-l-oxo- E19a, 1128 (R-X A R-M)... 

Imidazolidin 5-(l,2-Dibrom-2-phenyl-ethyl)-2,4-dioxo-5-methyl- V/4. 79... 

Ami no-2,4-dioxo-6-methyl-hexahydro- 557 4,6-Dimethyl-2-(4-ethyl-5-nitro-l,3-thiazol-2-ylthio)- 294... 

Further breakdown to mono-pyrrolic oxygenation products as further remains of Chls have also been considered (3, 102). These studies received further support from recent work by Shioi and coworkers, who obtained evidence for the presence of hematinic acid (4-methyl-2,5-dioxo-2,5-dihydropynole-3-propionic acid), ethyl-methyl-maleimide and a putative bicyclic degradation product of the ring-C-E section of Pheo a (103). 

Using an oxalic ester replaces a reactive hydrogen atom by an oxo ester (alkoxalyl) group.750 Thus diethyl 3-methyl-2-oxoglutarate is obtained in 70% yield from ethyl propionate and diethyl oxalate 751 and dimethyl dioxo-homonorcamphorate [methyl(3-methoxycarbonyl-2-oxocyclopentyl)glyoxalate] can be prepared in 90% yield from ethyl 2-oxocyclopentanecarboxylate and methyl oxalate 752... 

The synthesis of AM281 [A-(morpholin-4-yl)-l-(2,4-dichlorophenyl)-5-(4-iodophenyl) -methyl-l//-pyrazole-3-carboxamide] (61) is outlined in Scheme 15. 4 -Bromopropiophenone was reacted with diethyl oxalate in anhydrous diethyl ether under basic condihons to afford the lithium salt of ethyl 2,4-dioxo-3-methyl-4-(4-bromophenyl) butanoate 63, which was further reacted with 2,4-... 

Synonyms Dichlozolinate Ethyl 3-(3,5-dichlorophenyl)-5-methyl-2,4-dioxo-1,3-oxazolidine-5-carboxylate Ethyl 3-(3,5-dichlorophenyl)-5-methyl-2,4-dioxo-5-oxazolidine carboxylate Ethyl (RS) 3-(3,5-dichlorophenyl)-5-methyl-2,4-dioxo-1,3-oxazolidine-5-carboxylate Oxazolidine-5-carboxylic acid, 3-(3,5-dichlorophenyl)-2,4-dioxo-5-methyl-, ethyl ester Empirical C13H11CI2NO5... 

Oxazolidine A. See Dimethyl oxazolidine Oxazolidine-5-carboxylic acid, 3-(3,5-dichlorophenyl)-2,4-dioxo-5-methyl-, ethyl ester. See Chlozolinate Oxazolidinone CAS 70-07-5... 

In this connection it is important to mention the finding that the thioxo derivatives (52) can be converted in several ways to the 3,5-dioxo derivatives. By alkylation with methyl iodide in alkaline solution, methylmercapto derivatives (53) are produced which are readily hydrolyzed to dioxo derivatives. A similar course is followed in the reaction with ethyl chloroacetate. Finally, oxidation with hypo-... 

Chemical Name 7-[D-(-)-0 -(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-a-(4-hydroxyphenyl )acetamidol -3-[(1-methyl-1 H-tetrazol-5-yl)thiomethyl] -3[Pg.266]

To a suspension of 3.0 g of 7-[D-(-)-a-amino-p-hydroxyphenylacetamido] -3-[5-(1-methyl-1,2,3,4-tetrazolyl)thiomethyl] -A3arboxylic acid in 29 ml of water was added 0.95 g of anhydrous potassium carbonate. After the solution was formed, 15 ml of ethyl acetate was added to the solution, and 1.35 g of 4-ethyl-2,3-dioxo-1 -piperazinocarbonyl chloride was added to the resulting solution at 0°C to 5°C over a period of 15 minutes, and then the mixture was reacted at 0°C to 5°C for 30 minutes. After the reaction, an aqueous layer was separated off, 40 ml of ethyl acetate and 10 ml of acetone were added to the aqueous layer, and then the resulting solution was adjusted to a pH of 2.0 by addition of dilute hydrochloric acid. Thereafter, an organic layer was separated off, the organic layer was washed two times with 10 ml of water, dried over anhydrous magnesium sulfate, and the solvent was removed by distillation under reduced pressure. The residue was dissolved in 10 mi of acetone, and 60 ml of 2-propanol was added to the solution to deposit crystals. The deposited crystals were collected by filtration, washed with 2-propanol, and then dried to obtain 3.27 g of 7-[D-(-)-a-(4-ethyl-2,3-dioxo)-1 -piperazinocarbonylamino)-p-hydroxyphenylacetamido] -3-[5-(1 -methyl-1,2,3,4-tetrazolyl)thiomethyl]-A product forms crystals, MP 1BB°C to 190°C (with decomposition). 

R-( 1 a,2p,4p)]-2-ethyl-1,2,3,4,6,11 -hexahydro-2,5,7-trihydroxy-6,11 -dioxo-4-[[2,3,6-trideoxy-4-0-[2,6-dideoxy-4-0-[(2R-frani)-tetrahydro-6-methyl-5-oxo-2f/-pyran-2-yl]-a-L-/yxo-hexopyranosyl]-3-(dimethylamino)-a-L-/yx o-hexopyranosyl]oxy]-l-naphthacenecarboxylic acid methyl ester... 

CN [6i -[6a,7a,7(27 , 3 S )]]-7-[[2-[[(4-ethyl-2,3-dioxo-l-piperazinyI)carbonyl]amino]-3-hydroxy-l-oxobutyl]amino]-7-methoxy-3-[[( 1 -methyl- l//-tetrazol-5-yl)thio]methyl]-8-oxo-5-thia-1 -azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid... 

Stereostructures of a co-crystal of (li )-l- 4-[(9aA)-perhydropyrido[l,2- ]pyrazin-2-yl]phenyl -2-phenyl-7-hydroxy-l, 2,3,4-tetrahydroisoquinoline with ERa-LBD301-553/C — S triple mutant <2005JME364> and iV-[2-(4-hydroxyphenyl)ethyl]-a-propyl-3-[(4-hydroxyphenyl)methyl]-l,4-dioxo-l,2,3,4,ll,l la-hexahydro-67/-pyrazino[l,2- ]isoquinoline-3-acetamide with fructose-1,6-biphosphatase <2003JBC51176> were determined by X-ray crystallography. The structure of a complex formed from 3-[( -methylphenyl)amino]-4-[(4-methylphenyl)imino]-4//-pyrido[l,2-tf]pyrazine with sodium bis(trimethylsilyl)amide and (norbornadiene)Mo(CO)4 in THF was characterized by single crystal X-ray diffraction <1995JPR38>. 

The crystal structure of ethyl 4-(4-rert-butoxycarbonyl-l-piperazinyl)-5-fluoro-2,3-dihydro-l-methyl-2,7-dioxo-l//,7//-pyrido[3,2,l-iy]cinnoline-8-carboxylate (186, R = Et, R = tert-Qu, R = 4-tm-butoxycarbonyl-l-piperazinyl) was determined by means of X-ray diffraction investigation [95T11125]. 

Ring transformation of ethyl 2,4-dioxo-l,2,3,4-tetrahydropyrido[2,3- pyrimidine-5-carboxylates 317 with 80% hydrazine hydrate in boiling ethanol gave a mixture of 5-methyl/allyl/benzylamino-l,2,3,4-tetrahydro-l,4-dioxopyr-ido[3,4-i/ pyridazines 318, pyrido[2,3,4-< <7]pyridazino[3,4-/ [l,2,4]triazepines 319, and a low yield of 2,3,4,6,7-penta-azaphenalene 320. The reaction of 317 with hydrazine hydrate was also performed without a solvent in an oil bath at 125 °C for 1 h to give the same products, but higher yields of 318 and lower yield of 319 as well as traces of 320 were obtained (Equation 25) <1997FA657>. 

Versuche zur enantioselektiven Synthese von a-Aminosauren durch diastereoselektive Alkylierung des aus 2,4-Dioxo-3-[(7 )-l-phcnyl-ethyl]-imidazolidin mit Methoxycarbonyl-oxy-methyl-magnesium4 gebildeten Chelats blieben erfolglos Man erhalt ein 1 1-Dia-... 

When the above-mentioned ring expansion with diazomethane 74) of trimethyl-dioxo[2.2]metacyclophane 65 (methylation was necessary to increase the inversion barrier to > 130 kJ) was performed in the presence of optically active alcohols at —60 °C, asymmetric induction occurred to an extent of ca. 40% ee (enantiomeric excess as determined by nmr-spectroscopy in the presence of chiral shift reagents)85). (+)-DibutyI tartrate favoured the dextrorotatory diketone 66 ([a]D 160° for the optically pure product) — the isomeric 67 was formed only with 3% ee (—)-ethyl lactate on the other hand led to an excess of (+)-67 ([a]D +240°) but gave (+)-66 with only 10% ee85). 

Zi)-/V-Benzyl-/V- (1/ )-2-(ferf-butyldimethylsiloxy)-l-[(4V)-3,7-dioxo-1,2-diazepan-4-yl]ethyl)-2- [1-(phenylsulfonyl)-1/7-indol-3-yl]methyl)hexa-3,5-dienainide (63) lm ... 

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