The structure-activity relationships of some cyclopentadienyltitanium (IV) complexes of 1, 3-dihydro-1, 3-dioxo-α-(substituted)-2H-isoindole-2-acetates

The newly synthesized η-cyclopentadienyltitanium complexes of 1,3-dihydro-1, 3-dioxo-α-(substituted)-2H-isoindole-2-acetates have been screened for their toxicity against Columba livia (Gmelin) (the blue rock pigeon) and exhibit moderate toxicity towards this non-target bird. The bis- derivatives have been observed to be generally more active than the mono- ones, indicating the dominant contribution of ligands towards toxicity compared with cyclopentadienyl rings and chlorine atoms.     

Simple synthetic routes to 5-(3,6-dihydro-2-oxo-2H-1,3,4-thiadiazin-5-yl)-1H-indole-2,3-diones and their Derivatives

Two different synthetic routes to 5-(3,6-dihydro-2-oxo-2H-1,3,4-thiadiazin-5-yl)-1H-indole-2,3-diones are described. The reaction sequences represent a facile entry into these series of isatin derivatives.     

Stereoselective Synthesis of Alkyl Z -2-(2-Amino-4-oxo-1,3-thiazol-5(4 H )-yliden)Acetates in Solventless Conditions

Tiourea reacts with dialkyl acetylenedicarboxylates in solventless conditions to form 1:1 adducts, which undergo a cyclization reaction to produce alkyl Z-2-(2-amino-4-oxo-1,3-thiazol-5(4H)-yliden)acetates in fairly good yields. The stereochemistry of the ethyl Z-2-(2-amino-4-oxo-1,3-thiazol-5(4H)-yliden)acetate was established by the use of X-ray single crystal structure analysis. The reaction is completely stereoselective.     

Synthesis and Crystal Structure of 4-tert-Butyl-6-（4-chlorophenyl）-3,6- dihydro-2H-1,3-thiazin-2-iminium Chloride

The title compound, 4-tert-butyl-6-（4-chlorophenyl）-3,6-dihydro-2H-1,3-thiazin- 2-iminium chloride （C14H18C12N2S）, has been synthesized by the reaction of 1-（4-chlorophenyl）- 4,4-dimethylpent-1-en-3-one with thiourea, and its crystal structure was determined by single- crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P211c with a = 16.3064（11）, b = 9.4471（6）, c = 11.2626 （8）A, β = 108.400（1）°, Z = 4, V = 1646.28（19） A^3, Mr = 317.26, Dc = 1.280 g/cm^3, S = 1.078,μ = 0.510 mm^-1, F（000） = 664, the final R = 0.0514 and wR = 0.1412 for 3210 observed reflections （I 〉 2σ（I））. The thiazine ring system displays a twisted boat conformation, and three N-H,..Cl hydrogen bonds exist in the crystal. The combination of two N-H...Cl hydrogen bonds generate an R2^1 （6） ring.     

Synthesis of 3-[5-anilino-(2,3-d)-dioxole-1,3]-1-oxo-1,3-dihydro-2-benzofurane

A microscale synthesis (500 mg) of the product 3-[5-anilino-(2,3-d)-dioxole-1,3]-1-oxo-1, 3-dihydro-2-benzofurane (COR.01.126) is described. This method, which requires only four steps, is principally available for the ¹⁴C-labeled synthesis with labeled phthalic anhydride as starting material.     

Synthesis of 1,3-dihydro-5(r)-7,8-ethylenedioxy-2h-1,4-benzo-diazepin-2-ones

1,4-Diazepin-2-ones have been prepared from 1,4-benzodioxine for the first time.M. V. Lomonosov State University, Moscow 119899. Translated from Khimiya Geterotsiklcheskikh Soedinenii, No. 5, pp. 601–607, May, 1994. Original article submitted April 10, 1994.     

Synthesis of 5-(5-amino-3,6-dichloro-1,4-benzoquinon-2-yl)-2-dimethylaminothiazoles and their properties

In the reaction of 2-dimethylamino-5-(3,5,6-trichloro-1,4-benzoquinon-2-yl)thiazole with primary and secondary amines, the chlorine atom at the 5-position of the benzoquinone ring is substituted, according to the ¹³C NMR spectroscopy data, by an amino group. The chemical, spectroscopic, and electrochemical properties of 5-(5-amino-3,6-dichloro-1,4-benzoquinon-2-yl)-2-dimethylaminothiazoles were revealed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 410–415, March, 1991.     

Synthesis of 1,3-dialkyl-5-(pyrrol-1-yl)-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones

Russian Journal of Organic Chemistry -     

One-Pot Stereoselective Synthesis of Alkyl Z-2-[2-Amino-4-oxo-1,3-selenazol-5(4H)-yliden] Acetates

Abstract

Selenourea reacts with dialkyl acetylenedicarboxylates in acetone to form 1:1 adducts, which undergo a cyclization reaction to produce alkyl Z-2-(2-amino-4-oxo-1,3-selenazol-5(4H)-yliden) acetates in fairly good yields. The reaction is completely stereoselective.     

Formation of 3-[amino(aryl)-methylidene]-1,3-dihydro-2H-indol-2-ones involving ring transformation of 2-aryl-5-(2-aminophenyl)-4-hydroxy-1,3-thiazoles

The reaction of 3-bromooxindole with substituted (hetero)aromatic thioamides in acetonitrile was studied. At room temperature the reaction preferably gives products of ring transformation i.e. 2-aryl-5-(2-aminophenyl)-4-hydroxy-1,3-thiazoles (3b-f,h) whereas at elevated temperature products of an Eschenmoser coupling reaction, i.e. 3-[amino(aryl)-methylidene]-1,3-dihydro-2H-indol-2-ones (2b-f), are formed exclusively. There exist only two exceptions (4-methoxy and 2-pyridinthioamide) in which the Eschenmoser coupling reaction always takes place giving 2a and 2g. Also N-methylation of the starting 3-bromooxindole completely prevents formation of thiazoles. The prepared thiazoles 3b-f are unstable in solution and they undergo slow ring transformation to 2b-f. The rate limiting step of this rearrangement involves cleavage of an intermediary thiirane ring, which is slowed down by electron-withdrawing substituents on the thioamide (ρ = ?1.15).     

Acid-catalysed cyclisation of 2-methyl-2[3-(2,4-dimethoxyphenyl)-5-methoxypent-2-enyl]-cyclopentane-1,3-dione: Structure of a novel product

Acid-catalysed reaction of the title compound (3a) with boiling ethanolic HCl afforded a complex mixture of compounds from which a crystalline keto alcohol was isolated. On the basis of spectral data (UV, IR, NMR and MS), this keto alcohol was assigned the tricyclodecane structure 7a. Acetylation of the keto alcohol followed by hydrogenation gave the dihydro keto acetate 8b which was brominated using dioxane dibromide to give the bromo compound 8c. X-ray crystal structure analysis of the bromo compound confirmed the structure of this compound as well as the parent keto alcohol 7a.     

Determination of 7-iodo-1,3-dihydro-1-methyl-5(2'-fluorophenyl)-2h-1,4-benzodiazepin-2-one (Ro 7-9957) and its major biotransformation products in blood and urine by electron capture-gas-liquid chromatography.

A sensitive and specific electron capture-gas chromatographic assay was developed for the determination of 7-iodo-1,3-dihydro-1-methyl-5(2'-fluorophenyl)-2H-1,4-benzodiazepin-2-one (I) and its major metabolites in blood and urine. The overall recovery of I and its N-desmethyl metabolite (II) from blood is apparently quantitative. The recovery of the major urinary metabolite, the N-desmethyl-3-hydroxy analog (IV), and the minor metabolites, the N-desmethyl analog (II) and the N-methyl-3-hydroxy analog (III) added to urine as authentic reference standards ranged from 80 to 85%. The sensitivity limits of detection are of the order of 2-3 ng of I and 4-5 ng of II per ml of blood or urine. The method was applied to the determination of blood levels and the urinary excretion pattern in a dog following oral and intravenous administration of a 1-mg/kg dose (total 13 mg), and in man following the intravenous administration of single 5- and 10-mg doses. The N-desmethyl metabolite II was more predominant in dog blood than was the orally or intravenously administered I, but II was barely measurable in human blood.     

Eleuthesides and their analogs: IV. Synthesis of (1R,5R,6S)-6-(1,3-dithian-2-yl)-1-(2-hydroxyethyl)-5-methylcyclohex-3-ene and its O-tert-butyldimethylsilyl derivative

Two schemes for the preparation of chiral alcohols as key synthons for the synthesis of eleutheside analog at the A ring have been developed on the basis of the Diels-Alder adduct of levoglucosenone with piperylene.