Untersuchungen zur Synthese neuer tricyclischer Heterocyclen aus 1,4-Benzoxazin- und 1,4-Benzothiazin-3-oximen. 7. Mitteilung über Studien zur Chemie von O,N- und S,N-haltigen Heterocyclen

Summary The behaviour of amidoximes3 and4 under cyclization conditions is reported: Reaction with carbonyldiimidazole yields oxadiazolobenzoxazine11 and oxadiazolobenzothiazine12, respectively.

     

Studien zur Chemie von thienoanellierten O,N-und S,N-haltigen Heterocyclen, 5. Mitt.: Ein Zugang zum Thieno[2,3-b][1,4]oxazin-Ringsystem

Summary The reactivity of 5-acetyl-2-chloro-3-nitrothiophene with -hydroxyesters is described. The influence of the solvent (DMF, tetrahydrofurane, toluene) and of the used base is discussed. These reactions provide an access to substituted thiophene derivatives, which were cyclized after reduction by iron powder/glacial acetic acid to give thieno [2,3-b][1,4]oxazine derivatives.

     

Studien zur Chemie von thienoanellierten O,N- und S,N-haltigen Heterocyclen, 10. Mitt.: Synthese von 2- substituierten Thieno-Diltiazemderivaten

Summary The syntheses of 2-acetyl-, 2-benzyl-, and 2-ethyl-thieno-diltiazem derivatives are described starting from the corresponding 5-substituted 3-nitro-2-thiophenthiolvia reaction with racemic methyltrans-3-(4-methoxyphenyl)-glycidate under different conditions (solvent, catalyst, temperature) to obtain purethreo orerythro products. The nitro groups of these products were reduced and the resulting amino esters cyclized. The thieno[2,3-b][1,4]thiazepin-5(4H)-ones were N-alkylated and acetylated in position 3. The desired 2-substituted 4-(2-dimethylaminoethyl)-4,5,6,7-tetrahydro-7-(4-methoxyphenyl)-5-oxothieno[2,3-b][1,4]thiazepin-6-yl acetates were isolated in good yields.

     

Ein Beitrag zur Chemie des 2,3-Dihydro-3-oxo-benzo[b]thiophen-1,1-dioxids Synthesen mit Nitrilen, 86. Mitt.

Summary 2,3-Dihydro-3-oxo-benzo[b]thiophen-1,1-dioxide (1) reacts as CH-acidic component with amidines of orthoesters and anilines resp. to give the anilinomethylene derivates3, 4, and5. With triethyl orthoformiate the hydroxymethylene-compound7 is obtained. Anilino- and phenylhydrazino derivates8 and9 prove the carbonyl activity of1, azo-coupling leads to10, whereas treatment of1 with sulfur and malononitrile yields the benzo[b]thieno[2,3-d]thiophenes11. Introduction of substituents with active NH-functions in position 2 of the dicyanomethylene-product2, such as azocoupling, reaction with phenyl isocyanate and formation of enamines, leads to ring closure reactions between a nitrile and the NH-group. Thereby the phenyl-benzo[4,5]thieno[2,3-c]pyridazines12, the phenyl-1H-benzo[4,5]thieno[2,3-c]pyridines13 and the phenylamino-benzo[4,5]thieno[2,3-c]pyridines14 are obtained.¹³C and¹⁵N-NMR spectroscopy was used as proof of the ring closure reactions.

     

Heteroaromatization with Sulfonamido Phenyl Ethanone,Part I: Synthesis of Novel Pyrrolo[2,3-D]Pyrimidine and Pyrrolo[3,2-E][1,2,4]Triazolo[1,5-C]Pyrimidine Derivatives Containing Dimethylsulfonamide Moiety

4-(5-Amino-4-cyano-1-p-tolyl-1H-pyrrol-3-yl)-N,N-dimethyl-benzenesulfonamide (4) was prepared and converted to several pyrrolo[2,3-d]pyrimidin-5-yl)-N,N-dimethyl-benzenesulfonamide derivatives (5,7,9, and 13). Cyclocondensation of 13 with different electrophilic carbon reagents afforded several 4-(N,N-dimethylaminosulfonylphenyl)]pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]-pyrimidine derivatives (14–17,19, and 20); IR, ¹HNMR, and mass spectra of the newly synthesized compounds were recorded. Most of the obtained compounds were screened against Gram-positive and Gram-negative bacteria and fungi, for which some of these derivatives gave promising results.     

Acetylenchemie 7. Mitt.: Mechanistische Studien zur Synthese von Pyrano-[3,2-c]chinolin-Alkaloiden aus 4-Hydroxychinolin-2-onen und 3-Chlor-3-methylbut-1-in

The pyrano-cyclisation of 4-hydroxy-(1-methyl)-1H-quinoline-2-one with 3-chlor-3-methylbut-1-yne, supposed to proceed via an ether or vinyl intermediate, is studied by alkylating different 4-hydroxyquinolines. The nine derivatives characterized favour the ether-pathway (Späth type chromene synthesis).