Amidine als Zwischenprodukte bei Umamidierungsreaktionen. 9. Mitteilung über Umamidierungsreaktionen

Amidines as Intermediates in Transamidation Reactions By loss of water in the presence of p-toluenesulfonic acid/xylole N-aminoalkyllactames form bicyclic amidines. The corresponding N-alkylaminoalkyl-lactames' react to bicyclic amidinium salts or to transamidated products, ring-enlarged by the N-alkylamino residue, respectively (s. Scheme 1). The bicyclic amidines and amidinium salts are partially hydrolyzed by KOH/H₂O to lactames (s. Scheme 2). Which of the two possible isomeric lactames are formed is discussed.     

Chinazoline und 1,4-Benzodiazepine, 35. Mitt.: Darstellung und Umlagerungsreaktionen eines 3,1,4-Benzoxadiazepines

Zusammenfassung Das 7-Chlor-2-methylamino-5-phenyl-3,1,4-benzoxadiazepin wurde dargestellt und die Umlagerungsreaktionen dieser Verbindung wurden untersucht. Je nach den Reaktionsbedingungen wurden Indazol-, Benzoxazin- oder Chinazolinderivate erhalten.

---

7-Chloro-2-methylamino-5-phenyl-3,1,4-benzoxadiazepine was prepared and the rearrangement reactions of this compound were investigated. Depending on the reaction conditions, indazole, benzoxazine or quinazoline derivatives were obtained.

---

---

Meinem hochverehrten Lehrer, Herrn Professor Dr.F. Wessely zum 70. Geburtstag gewidmet! Werner Metlesics.

---

34. Mitt.:A. Stempel, I. Douvan, E. Reeder undL. H. Sternbach, J. Org. Chem., im Druck.     

Reaktionen bei dem thermochemischen ZnSe-Cyclus zur Darstellung von Wasserstoff

Ohne Zusammenfassung     

Eine einfache Methode zur Bestimmung des Prothrombinverbrauchs als diagnostischen Test bei Blutuntersuchungen

Ohne Zusammenfassung     

Versuche zur Darstellung von Dicyanoxid

Zusammenfassung Alkalicyanate reagieren mit Cyanchlorid zu einer Verbindung C₅N₅O₃ M (M=K, Cs), wobei vermutlich Dicyanoxid als Zwischenprodukt gebildet wird. Als Strukturformel wird die eines Alkalisalzes des 4,6-Dicyanato-s-triazin-2-ols angenommen. Bei der Vakuumthermolyse des Salzes entsteht ab 650° Cyanisocyanat. Bei der Reaktion von Tetracyanmethan mit Alkalicyanaten entsteht Tricyanmethylalkalisalz und ein Polymeres, das nicht mehr depolymerisierbar ist. Bei keiner der untersuchten Reaktionen konnte monomeres Dicyanoxid isoliert werden.

---

Attempted synthesis of dicyanogen oxide

Alkali cyanates react with cyanogen chloride to C₅N₅O₃ M (M=K, Cs), which probably is formed via dicyanogen oxide as an intermediate. The compound is assumed to be an alkali salt of 4.6-dicyanato-s-triazin-2-ol. On pyrolysis in vacuo cyanogen isocyanate is formed above 650°. Tetracyanomethane reacts with alkali cyanates to tricyanomethanide alkali salt and a polymer, which cannot be depolymerized. No monomeric dicyanogen oxide could be isolated.

     

Notiz zur Darstellung vonN-substituierten Aminoglycerinaldehyden

O-Benzyl-N-(benzyloxycarbonyl)-DL-serine methyl ester (1a) and peptides1 b–d with C-terminalO-benzylserine ester have been reduced with diisobutylaluminium hydride to yield the N-substituted aminoglyceraldehydes2 a–d. Using lithium tetrahydridoaluminate as the reducing agent the corresponding alcohols3 a–d have been obtained.

Herrn Dr.Albert Groß (Fa. Kulzer) zum 60. Geburtstag gewidmet.     

Synthetic Strategies Applicable in the Synthesis of Privileged Scaffold: 1,4-Benzodiazepine

The development of new synthetic approaches to the 1,4-benzodiazepine ring system and their further elaboration have provided access to a broad range of functionalized derivatives. In this review an attempt has been made to summarize those synthetic strategies involved for the synthesis of privileged scaffold 1,4-benzodiazepine over time.     

Eine Blockierungsmethode zur Darstellung molekulareinheitlicher Hydroxyphenylenmethylen-Verbindungen

Ohne Zusammenfassung     

Eine biamperometrische Methode zur Bestimmung einiger Zwischenprodukte beim Abbau von Hyodesoxychols?ure

Ohne Zusammenfassung     

Chalkogenoniobate als Ausgangsverbindungen zur Darstellung neuer heterobimetallischer Niobium‐Münzmetall‐Chalkogenido‐Cluster

Chalcogenoniobates as Reagents for the Synthesis of New Heterobimetallic Niobium Coinage Metal Chalcogenide Clusters In the presence of phosphine chalcogenoniobates such as Li₃[NbS₄] · 4 CH₃CN ( I ), (NEt₄)₄[Nb₆S₁₇] · 3 CH₃CN ( II ) and (NEt₄)₂[NbE′₃(E^tBu)] ( III a : E′ = E = S; III b : E = Se, E′ = S; III c : E = E′ = Se) respectively react with copper and gold salts to give a number of new heterobimetallic niobium copper(gold) chalcogenide clusters. These clusters show metal chalcogenide units already known from the complex chemistry of the tetrachalcogenometalates [ME₄]^n– (M = V, n = 3, E = S; M = Mo, W, n = 2, E = S, Se). The compounds 1 – 8 owe a central tetrahedral [NbE₄] structural unit, which coordinates η² from two to five coinage metal atoms, employing the chalcogenide atoms of the [NbE₄] edges. The compounds 9 – 11 have a [M′₂Nb₂E₄] (M′ = Cu, Au) heterocubane unit in common, involving a metal metal bond between the niobium atoms, while the compounds 12 and 13 show a complete and 14 an incomplete [M′₃NbE₃X] heterocubane structure (X = Cl, Br). 15 consists of a Cu₆Nb₂ cube with the six planes capped by μ₄ bridging selenide ligands forming an octahedra. The compounds 1 – 15 are listed below: (NEt₄) [Cu₂NbSe₂S₂(dppe)₂] · 2 DMF ( 1 ), [Cu₃NbS₄(PPh₃)₄] ( 2 ), [Au₃NbSe₄(PPh₃)₄] · Et₂O ( 3 ), [Cu₄NbS₄Cl(PCy₃)₄] ( 4 ), [Cu₄NbS₄Cl(P^tBu₃)₄] · 0,5 DMF ( 5 ), [Cu₄NbSe₄(NCS)(P^tBu₃)₄] · DMF ( 6 ), [Cu₄NbS₄(NCS)(dppm)₄] · Et₂O ( 7 ), [Cu₅NbSe₄Cl₂‐ (dppm)₄] · 3 DMF ( 8 ), [Cu₂Nb₂S₄Cl₂(PMe₃)₆] · DMF ( 9 ), [Au₂Nb₂Se₄Cl₂(PMe₃)₆] · DMF ( 10 ), (NEt₄)₂[Cu₃Nb₂S₄(NCS)₅(dppm)₂(dmf)] · 4 DMF ( 11 ), [Cu₃NbS₃Br(PPh₃)₃(dmf)₃]Br · [CuBr(PPh₃)₃] · PPh₃ · OPPh₃ · 3 DMF ( 12 ), [Cu₃NbS₃Cl₂(PPh₃)₃(dmf)₂] · 1.5 DMF ( 13 ), (NEt₄)[Cu₃NbSe₃Cl₃(dmf)₃] ( 14 ), [Cu₆Nb₂Se₆O₂(PMe₃)₆] ( 15 ). The structures of these compounds were obtained by X‐ray single crystal structure analysis.     

Notiz zur Darstellung von 4-Hydroxy-6-methyl-5,6-dihydro-2H-pyran-2-on

Meldrum's acid (2) is acylated by diketen affording the acylMeldrum's acid3. In aqueous bicarbonate its 3-oxogroup is selectively reduced by sodium tetrahydroborate giving the alcohol4, which readily undergoes cyclization in refluxing dioxane leading to the title pyrone7. Under identical conditions3 produces the pyrone6 with the pyrone carboxylic acid5 as intermediate.