Schmidt Reaction on 2-Aryl-1,2,3,4-tetrahydro-4-quinolone

Synthesis and stereochemistry of 2-aryl-1,2,3,4-tetrahydro-5H-1,4-benzodiazepin-5-one and 2-aryl-2,3-dihydro-4H-tetrazolo [1,5-d]-1H-1,4-benzodiazepine is reported by the Schmidt reaction on 2-aryl-1,2,3,4-tetrahydro-4-quinolone.     

Synthesis of 5-substituted 6-methoxy-1,2,3,4-tetrahydro-β-carbolin-1-ones

The nitration and bromination of 6-methoxy-1,2,3,4-tetrahydro--carbolin-1-one were studied. 5-Nitro and 5-bromo derivatives were obtained. 5-Acetyl-1,2,3,4-tetrahydrocarbolin-1-one oxime was obtained, and its Beckmann rearrangement was studied. The use of lithium aluminum hydride leads to reduction of the 5-acetyl group to give an alcohol group, whereas reduction of the acetyl group to an ethyl group occurs in the case of reduction with a palladium catalyst. Saponification of 5-substituted carbolin-1-ones with alcoholic alkali makes it possible to obtain 4-substituted tryptamines with a carbonyl group in the 2 position. The structures of the compounds were established by means of the PMR and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 80–85, January, 1979.     

Derivate des 5, 9-Methano-6, 7,8, 9-tetrahydro-5 H-benzocycloheptens und Umlagerungen zum 1, 4-Äthano-1,2,3,4-tetrahydronaphtalin-System

Derivatives of 5,9-Methano,7,8,9-tetrahydro-5H-benzocycloheptene and Rearrangements to the 1,4-Ethano-I,2,3,4-tetrahydronaphthalene System Reduction of the oxime 2 with Raney alloy gives the amine 3a , with AlH₃ a mixture of the isomeric amines 3a and 3b , whilst LiAlH₄ yields the aziridines 4a and 4b . The bicyclo[3.2.1]octane 4b rearranges under acidic conditions to the bicyclo[2.2.2]octane 5 . The olefin 7 can be converted to the aminoalcohol 9 via the epoxide 8 and to the amine 13 using iodine isocyanate: the carbon skeleto. remains intact. However, treatment of the olefin 17 with iodine isocyanate leads to the bicyclo[2.2.2]octanes 21 and 24 in which a skeletal rearrangement has taken place. The configuration was determined by NMR. and X-ray analysis.     

Conformation of 1,2,3,4-tetrahydro-2-pyrimidinones

The conformation of a number of 1,2,3,4-tetrahydro-2-pyrimidinones with various substituents in the ring was established on the basis of the vicinal ³J₃₄ constants found from the ¹H NMR spectra of these compounds. It is shown that in solution rapid conformational transformations between the two possible boat conformations evidently occur.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 524–525, April, 1981.     

Bromine-substituted 1,2,3,4-tetrahydro-4-methylspiro[quinoline-2-cyclohexanes]

The bromination of 1,2,3,4-tetrahydro-4-methylspiro[quinoline-2-cyclohexane] has been carried out under various conditions. Dibromo and monobromo derivatives have been obtained; the monobromo derivatives were synthesized by cyclization of 1-allyl-1-bromophenylaminocyclohexanes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1350–1353, October, 1991.     

Conversions of 5-hydroxy-5, 6-dihydro-4H-1, 2, 5-oxadiazines

Oxidation of 5-hydroxy-5, 6-dihydro-4H-1, 2, 5-oxadiazines leads to the formation of 6H-1,2, 5-oxadiazine-5-oxides. Acid treatment of 5, 6-dihydro-4H-1, 2, 5-oxadiazines and 6H-1, 2, 5-oxadiazine-5-oxides results in heterocyclic-ring contraction with the formation of imidazole 3-oxides and 1-hydroxyimidazole 3-oxides. The structures of the products are established by their spectral properties and confirmed by independent synthesis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1264–1266, September, 1970.     

Preparation of 4-aryl-1,2,3,4-tetrahydro-3,3-dimethylisoquinolines and 1,2,3,4-tetrahydro-3,3-dimethyl-4-phenylbenz[h]isoquinolines

Synthetic procedures to prepare a number of 4-aryl-1,2,3,4-tetrahydro-3,3-dimethylisoquinolines and their benzo-homogues 3 through a series of intermediates are described. The condensation of α-(1-amino-1-methylethyl)arylmethanols 5 with arylaldehydes 6 gave imino derivatives 7 which on reduction with borohydride gave secondary amines 8 . The treatment of 8 with mineral acids gave the target compounds 3 . Biological activities of 3 are briefly discussed.     

Free-radical oxidation of 1,2,3,4-tetrahydro-2-oxopyrimidines

Abstract  

Free-radical oxidation of 4-substituted 5-acetyl- and 5-carboethoxy-1,2,3,4-tetrahydro-2-oxopyrimidines using benzoyl peroxide under thermal conditions has been investigated to elucidate the effects of the nature of the substituents in the 4- and 5-positions on the rate of reaction. Whereas the presence of the acetyl group instead of the carboethoxy group in position 5 decreases the rate of oxidation, the nature of the additional substituent (electron-releasing or electron-withdrawing group) and also its location on the phenyl ring attached to C-4 of the tetrahydropyrimidinone ring effectively influence the rate of reaction. The latter observation supports the proposal that the removal of the 4-hydrogen on the heterocyclic ring occurs in the rate-determining step.     

Combinatorial solid-phase synthesis of 6-hydroxy-1,2,3,4-tetrahydro-beta-carbolines from l-5-hydroxytryptophan

A library of biologically relevant 6-hydroxy-tetrahydro-beta-carbolines (6-OH-THBCs) based on the L-5-OH-tryptophan scaffold was prepared. A solid-phase synthesis was developed, utilizing aminomethyl polystyrene resin and solid-phase-optimized reactions, such as Pictet-Spengler condensation. The library was designed such that three points of diversity would be readily introduced, making the strategy potentially suitable for generation of a large number of compounds.     

Beiträge zur Chemie des Phosphors. 66. Kristall- und Molekülstrukturen von 1,2,3,4-Tetraphenyl-cyclo-5-carba-1,2,3,4-tetraphosphan, (PC6H5)4CH2, und 1,4-Dithio-1,2,3,4-tetraphenyl-cyclo-5-carba-1,2,3,4-tetraphosphan, (PC6H5)4CH2S2

Contributions to the Chemistry of Phosphorus. 66. Crystal and Molecular Structure of 1,2,3,4-Tetraphenyl-cyclo-5-carba-1,2,3,4-tetraphosphane, (PC₆H₅)₄CH₂, and 1,4-Dithio-1,2,3,4-tetraphenyl-cyclo-5-carba-1,2,3,4-tetraphosphane, (PC₆H₅)₄CH₂S₂ The following results were achieved by X-ray structure analyses of 1,2,3,4-Tetraphenyl-cyclo-5-carba-1,2,3,4-tetraphosphane 1 and 1,4-Dithio-1,2,3,4-tetraphenyl-cyclo-5-carba-1,2,3,4-tetraphosphane 2 :

• crystallises in the monoclinic space group Cc with a = 22.272, b = 13.726, c = 7.492 Å, β = 96.82° and Z = 4. The P₄C-ring has an envelope conformation. The phenyl groups are arranged alternately on both sides of the ring.
• forms triclinic crystals, space group P1 , with a = 10.900, b = 10.663, c = 12.233 Å, α = 106.26, β = 100.04, γ = 70.65°, Z = 2. The P₄C-ring has twist conformation, the carbon atom lies almost in the mean plane of the ring. The sulfur atoms are bonded in exo position to the phosphorus atoms neighbouring the carbon atom and in trans position to each other.

     

Short syntheses of 1,2,3,5-tetrahydro-5-oxopyrrolo-[1,2-a]quinoline-4-carboxylic acid and 1,2,3,4-tetrahydro-6H-6-oxopyrido[1,2-a]quinoline-5-carboxylic acid derivatives

Short and efficient syntheses of 7-fluoro-8-(4-methylpiperazin-1-yl)-1,2,3,5-tetrahydro-5-oxopyrrolo[1,2-a]-quinoline-4-carboxylic acid and 8-fluoro-9-(4-methylpiperazin-1-yl)-1,2,3,4-tetrahydro-6H-6-oxopyrido[1,2-a]-quinoline-5-carboxylic acid are described. Both basic heterocycles were synthesized in two steps by the condensation of a benzoylacetate with an imino ether followed by an intramolecular nucleophilic displacement cyclization reaction.