Ring synthesis 3-ethoxycarbonyl

A new, broadly based synthesis of l,4-benzodiazepine-3,5-diones has been described by Bergman et al. <04JOC6371>. It utilises the A-substituted anthranilic acid 86, which was N-nitrosated to give 87 and then cyclized to the dione 89 via 88. Removal of the A-nitroso group then afforded 90 this represents a novel use of the A-nitroso group in 7-membered ring synthesis. The compound 91 was also used to prepare an A-ethoxycarbonyl derivative of 90. 

Azepine, 5-bromo- 1-ethoxycarbonyl-X-ray crystallography, 7, 520 1 //-Azepine, 5-cyano-4,5-dihydro-rearrangement, 7, 512 1 //-Azepine, 3-cyclopropyl-2-diethylamino-synthesis, 7, 536 1//-azepine, 2,6-dicyano-ring contractions, 7, 506 1//-Azepine, 2,3-dihydro-synthesis, 7, 42 1 //-Azepine, 2,5-dihydro-valence tautomerism, 7, 506 1 //-Azepine, 2,7-dihydro-rearrangement, 7, 507 1//-Azepine, 4,5-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... 

The synthesis of CMDBSSu involves the random carboxymethylation of hydroxyl groups on the glucose units, the benzylamidation of some of the carboxylic groups with benzylamine in the presence of N-ethoxycarbonyl-2-ethoxy-l,2-dihydroquinoline (EEDQ) to carboxymethyl dextran benzylamide (CMDB), the sulfonation of phenyl rings and sulfation of remaining hydroxyl groups at the polymer backbone (Fig. 39, [108,222]). 

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