4.5- Dicarboxy-2-methyl

Furazan-2-oxid 3,4-Diactyl- E8c, 736 (H3C-CO-CH3 + HN03) Imidazo 4,5-Dicarboxy-2-methyl-E8c, 13... 

Further elucidation of the structure of insularinic acid came when it (LXXII) was heated at 130-145° in a sealed bomb with hydrogen bromide for one and one-half hours. The resulting product (LXIXVIII) on catalytic reduction followed by methylation with diazomethane and saponification yielded 4,5 -dicarboxy-2 -methyl-2,3-dimethoxydiphenyl ether (LXXIX). This was synthesized from the potassium salt of methyl 4-hydroxy-3-methylbenzoate and methyl 3-bromo-4,5-dimethoxybenzoate by the Ullmann condensation. 

Estradiol-17 8 slows the inactivation and excess /J-mercaptoethanol stops it. When tritiated 16a-bromoacetoxyestradiol 3-raethyl ether is used, subsequent hydrolysis and amino acid analyses indicate dicarboxy-methylation of a histidyl residue at the site of enzyme catalysis. The histidyl residue labeled by this procedure must certainly be different... 

Thiazolo[3,2-a]pyridinium, anhydro-5-chloro-2,3-dihydro-8-hydroxy- H NMR, 6, 675 <77ACS(B)919) Thiazolo[3,2-a]pyridinium, anhydro- 2a,3y8-dicarboxy-2,3 -dihy dro-5-methyl-X-ray, 6, 670 (71 ACS 118) Thiazolo[3,2-a]pyridinium, anhydro-2,3-dihydro-8-hydroxy-... 

Pyridinium salts, 3-cyano-l-methyl-covalent amination, 2, 239 Pyridinium salts, 3,5-dicarboxy-l-methyl-reactions... 

Thiazolo[3,2-a]pyridinium hydroxide, anhydro-2a,3/3-dicarboxy-2,3-dihydro-5-methyl-structure, 6, 672 X-ray diffraction, 6, 670... 

Thiophene, 3,5-di-t-butyl-2-methyl-sulfonation, 4, 764 Thiophene, 2,4-dicarboxy-synthesis, 4, 870 Thiophene, 2,3-dichloro-synthesis, 4, 933 Thiophene, 2,5-dichloro-synthesis, 4, 933 Thiophene, 3,4-dichloro-... 

Optical activity owing to restricted rotation (atropisomerism) has been demonstrated in two phenylthiophenes 2-(6-methyl-2-nitro-phenyI)-3-thiophenecarboxylic acid (41), which rapidly racemized in solution, and 2,5-dimethyl-4- (6 -methyl-2 -nitrophenyl) 3-thio-phenecarboxylic acid (42), which was optically stable (at room temperature). Recently the first bithienyl, 2,2 -dicarboxy-4,4 -dibromo-5,5 -dimethyl-3,3 -bithienyl (43), has been resolved into optical anti-podes which were optically stable. 

Amino-2 -methyl-4,5-bis-[hydroxymethyl]- 158 3 -Amino-2 -methyl-4,5 -dicarboxy- 158... 

Nitro-2-athoxycarbonyl- 694 2 -Nitro-2-carboxy- 694 2-Nitro-2 -formyl- 693 Octachlor-4,4 -bis-[trichlor-vinyl]- 62 7 Octachlor-4,4 -diathinyl- 627 Octachlor-4 -(trichlor-vinyl)-4-athinyl- 627 2,2, 6,6 -Tetrakis-[hydroxyamino]- 695 2,2, 6,6 -Tetranitro- 695 2,2, 4,4 -Tetranitro-6.6 -dicarboxy- 689 4,4, 6,6 -Tetranitro-2,2 -dicarboxy- 660 2-(Trichlorsilyl-methyl)- 555... 

Dicarboxy-l-methyl-imidazol kann selektiv sowohl zu 5-Carboxy-l-methyl-imidazol (Erhitzen in Acetanhydrid auf 100° 95%) als auch zu 4-Carboxy-l-methyl-imidazol (Erhitzen in Dimethylacetamid auf 180° 64-75%) decarboxyliert werden534, 535. Durch Erhitzen in Anilin wird 4-Anilinocarbonyl-l-methyl-imidazol erhalten535. 

Carboxy-l-methyl-imidazol535 Man erhitzt eine Suspension von 3,4 g (20 mmol) 4,5-Dicarboxy-l -methyl-imidazol in 100 ml Essigsaureanhydrid 4 h auf 100°. Die danach homogene Reaktionsmischung wird i. Vak. zur Trockene eingedampft. Dann wird der Ruckstand mit Aceton gewaschen und aus Ethanol umkristal-lisiert Ausbeute 2,5 g (99%) Schmp. 257° (Zers.),... 

Die Carboxy-methyl-furazan-2-oxide sind stabiler als 3,4-Dicarboxy-furazan-2-oxid (s.u.) das trockene Kalium-Salz von 3-Carboxy-4-methyl-furazan-2-oxid ist explosiv (Erwarmen auf 115°)399. Zu weiteren Reaktionen der Carboxy-methyl-furazan-2-oxide s. Lit.398,400-402. 

Diphenyl-4,10-dicarboxy-6-methyl-l,7-phenanthroline (25) has been obtained179 along with the quinoline derivative (24) by the alkaline condensation of acetophenone with the substituted isatin (23). 

A mixture of palladium chloride and triphenylphosphine effectively catalyzes carboxylation of linoleic and linolenic acids and their methyl esters with water at 110°-140°C and carbon monoxide at 4000 psig. The main products are 1,3-and 1,4-dicarboxy acids from dienes and tricarboxy acids from trienes. Other products include unsaturated monocar-boxy and dicarboxy acids, carbomethoxy esters, and substituted a,J3-unsaturated cyclic ketones. The mechanism postulated for dicarboxylation involves cyclic unsaturated acylr-PdCl-PhsP complexes. These intermediates control double bond isomerization and the position of the second carboxyl group. This mechanism is consistent with our finding of double bond isomerization in polyenes and not in monoenes. A 1,3-hydrogen shift process for double bond isomerization in polyenes is also consistent with the data. 

To elucidate further the reaction sequence, competitive catalytic carboxylation was studied with mixtures of methyl linoleate and conjugated linoleate. At 120 °C methyl linoleate carboxylates initially more rapidly than conjugated linoleate (Figure 3). With this mixture, monocarboxy acids are formed in larger amounts than the dicarboxy acids. 

Figure 8 shows kinetic data on the catalytic hydrocarboxylation of methyl linolenate. There is initial conjugation of the triene system. Monocarboxy acids formed as initial products peak after 2 hrs and disappear almost completely. The dicarboxy acids are important intermediates and carboxylate further to give tricarboxy acids. The conversion to tricarboxy acids at 140°C does not exceed 50 to 53% (Runs 9 and 11, Table I). Cyclic ketones are formed as in linoleate in small but significant amounts. 

Oxidation of the methyl group occurs during TNT manuf, with 2-4% of yield loss occurring in this way (Ref 62). Under certain conditions, the alcohol (as its nitrate) and the aldehyde are thus formed they react to form 2,2f-dicarboxy-3,3 f,5,5 -tetranitroazoxybenzene ( white compound ) ... 

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