2- Amino-3-ethoxycarbonyl-4- 3,4-dihydro

Thiophene, 2-amino-3-cyano-5-phenyl-synthesis, 4, 888-889 Thiophene, 3-amino-4,5-dihydro-cycloaddition reactions, 4, 848 Thiophene, 2-amino-3-ethoxycarbonyl-ring opening, 4, 73 Thiophene, 2-amino-5-methyl-synthesis, 4, 73 Thiophene, 2-anilino-synthesis, 4, 923-924 Thiophene, aryl-synthesis, 4, 836, 914-916 Thiophene, 2-(arylamino)-3-nitro-synthesis, 4, 892 Thiophene, azido-nitrenes, 4, 818-820 reactions, 4, 818-820 thermal fragmentation, 4, 819-820 Thiophene, 3-azido-4-formyl-reactions... 

Chloro-3- [(1 -ethoxycarbonyl-1 -methylethyl)amino] -4-nitrobenzene (61) gave 6-chloro-3,3-dimethyl-3,4-dihydro-2(l //)-quinoxalinone (62) (TiCl3, AcONa, HeO-MeOH, 20°C, 2.5 h >95%).1042... 

R1 = R2 = H) gave the triazolo[l,5-a]pyrimidines (125), but with 124 (R1 = R2 = Me) afforded the dioxo derivative 126, and with a-cyano- y-butyrolactones (127) or 2-amino-3-ethoxycarbonyl-5,6-dihydro-4//-thiopyran (129) gave the triazolopyrimidines 128 and 130, respectively (81JHC1287). Treatment of 4-ethoxymethylene-2-phenyl-5(4//)-oxazolone (131) with 5-amino-3-methylthio-l//-1,2,4-triazoles gave the triazolo[l,5-a]pyrimidi-none 132 and the [4,3-a] isomer 133 (93H955) (Scheme 24). 

A suspension of the diazonium salt in toluene was gradually heated and kept at 120°C (bath temp.) for 30 minutes with stirring. After evaporation of the solvent under reduced pressure, the residue was made alkaline with 10% sodium carbonate and then extracted with chloroform. The chloroform extract was dried over anhydrous potassium carbonate. After evaporation of the solvent, the crystalline residue was recrystallized from ethyl acetate to give 6-acetylamino-2-(4-ethoxycarbonyl-l-piperazinyl)-3-fluoropyridine (mp 132°-133°C). The 3-fluoro derivative was hydrolyzed with a mixture of 15% hydrochloric acid and methanol (1 2 v/v) to give 6-amino-2-(4-ethoxycarbonyl-l-piperazinyl)-3-fluoropyridine. This compound was treated with diethyl ethoxymethylenemalonate at 130°-140°C to give N-[2-(4-ethoxycarbonyl-l-piperazinyl)-3-fluoro-6-pyridinyl]aminomethylenemalonate (mp 144°-145°C) and then the product was cyclized by heating at 255°C to give ethyl 7-(4-ethoxycarbonyl-l-piperazinyl)-6-fluoro-l,4-dihydro-4-oxo-l,8-naphthyridine-3-carboxylate (mp 279°-281°C). 

The starting material is produced by reacting 6-amino-2-methylthiopyrimidine with ethoxymethylene malonic acid diethyl ester. That intermediate is thermally treated in diphenyl ether to give 6-ethoxycarbonyl-2-methylthio-5-oxo-5,8-dihydro-pyrido[2,3-d]pyrimidine. The ethoxy group is hydrolyzed off with sodium hydroxide and one nitrogen is ethylated with diethyl sulfate to give the starting material. These are the same initial steps as used in the pipemidic acid syntheses earlier in this volume. 

Amino-3-cyanobenzodiazepinium chloride reacted with sodium boro-hydride to give a mixture of 2,3-dihydro- and 2,3,4,5-tetrahydro-3-cyano-benzodiazepines. It was suggested that deamination, brought about by hydride attack at C-2, preceded reduction (81CPB1165). Similar reduction of the 2-amino-3-ethoxycarbonyl analog provided only 3-ethoxycarbonyl-2,3-dihydrobenzodiazepine. 

H-Pyran 6-Methoxycarbonyl-amino-5,6-dihydro- VI/4, 363 Pyrrolidine (S)-2-Ethoxycarbonyl-5-oxo- E21f, 5814 (2-NH2-pentandioic Acid Cyclisier.)... 

Pentan 3-Aminomethylen-2,4-dioxo-1-ethoxy- XI/1. 199 4H-Pyran 6-(Ethoxycarbonyl-amino)-5,6-dihydro- Vl/4, 363 3H-Pyrrol... 

Azetidin 2-Oxo-l-(2,4,6-trimethoxy-benzyl)- El6b, 550 (aus Azetidin) 1-Benzofuran 3-Amino-2,3-dime-thyl-2-ethoxycarbonyl-5-hydro-xy-2,3-dihydro- E6b/1, 109 [HjC—C(NH2) = C(CH3) -COOR 1,4-Chinon] Bernsteinsaure -(benzyloxyamid)-ethylester E5, 1151 (R —CO — CHN2 + Ar —O—NH2) Carbamidsaure N-(4-Methyl-... 

Heating equimolar amounts of 5-amino-l-methylimidazole-2(3//)-thione (391) with diethyl ethoxymethylenemalonate (390) gave the diethyl ester of [(5-amino-2,3-dihydro-1-methyl-2-thioxo-lH-imidazol-4-yl)methylene]propanedioic acid (392), which cyclized in 10% aqueous sodium hydroxide to 6-ethoxycarbonyl-3-methyl-2(lH)-thioxoimidazo[4,5-fc]pyridin-5(4//)-one (393) (78H(10)24l). 

Bei der Behandlung von 3-Amino-5-ethoxycarbonyl-4-methyl-2-methylimino-2,3-dihydro-l,3-thiazol mit Natriumnitrit kommt es zur Deaminierung und Einfiihrung einer Nitroso-Gruppe in die 2-standige Amino-Gruppe1129 ... 

Alkyl-5-ethoxycarbonyl-1 -phenyl- 673 6-Amino-l-methyI-7-oxo-5-phenyI-6,7-dihydro- 673... 

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