Alkaloids of the Australian Rutaceae: Pentaceras australis Hook. F. I. Isolation of the Alkaloids and Identification of Canthin-6-one

1952 ◽  
Vol 5 (2) ◽  
pp. 387 ◽  
Author(s):  
HF Haynes ◽  
ER Nelson ◽  
JR Price
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Trans Isomer ◽  
Total Yield ◽  
Forest Tree ◽  
Ring System ◽  
Root Bark ◽  
Mature Trees ◽  
Plant Kingdom ◽  
Lactam Ring

Three alkaloids, with molecular formulae C14H8ON2, C15H10O2N2, and C15H10OSN2,, have been isolated from the ram-forest tree Pentaceras australis Hook. f. All three are present in the bark of mature trees, the total yield of alkaloids varying from c. 0.2 per cent. (branch bark) to c. 1 per cent. (root bark). The wood contains 0.2 per cent. of a mixture of two of the alkaloids, C14H8ON2 and C15H10OSN2, while the leaves contain less than 0.01 per cent. of a mixture in which the alkaloids C14H8ON2 and C15H10O2N2 are present.The alkaloid C14H8ON2 is shown to be representative of a ring system not previously found In the plant kingdom. It is canthm-6-one (II). The principal reactions on which this structure is based are (a) oxidation of the alkaloid to β-carboline-1-carboxylic acid and (b) the reversible opening of a lactam ring with alkali to give cis-2-(1'-β-carbolyl) acrylic acid (III) which may be transformed to the trans-isomer from which the alkaloid is not regenerated. Other reactions of the alkaloid support the canthinone structure. Among the compounds described is a dihydro-derivative (XI) of the parent base canthine

scholarly journals Crystal structure of (E)-2-cyano-3-(12-methyl-12H-benzo[b]phenothiazin-11-yl)acrylic acid

2014 ◽  
Vol 70 (9) ◽  
pp. o1026-o1027
Author(s):  
Motonori Watanabe ◽  
Tatsumi Ishihara
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Acrylic Acid ◽  
Bond Angle ◽  
Ring System ◽  
Boat Conformation ◽  
Compound C ◽  
Thiazine Ring ◽  
Donor Acceptor

In the title compound, C21H14N2O2S, a donor–acceptor type of benzo[b]phenothiazine (bpz) derivative, the thiazine ring adopts a boat conformation and the bond-angle sum at the N atom is 360.0°. The dihedral angle between the benzene ring and the naphthelene ring system fused to the thiazine ring is 32.76 (5)°. In the crystal, carboxylic-acid inversion dimers linked by pairs of O—H...O hydrogen bonds generateR22(8) loops. Aromatic π–π stacking [shortest centroid–centroid separaton = 3.5242 (13)Å] consolidates the structure and very weak C—H...O and C—H...N interactions also occur.

Alkaloids of the Australian Rutaceae: Pentaceras australis Hook. F. III. Identification of 4-Methylthiocanthin-6-one

1952 ◽  
Vol 5 (4) ◽  
pp. 768 ◽  
Author(s):  
ER Nelson ◽  
JR Price
Keyword(s):  
Carboxylic Acid ◽  
Hydrochloric Acid ◽  
Acrylic Acid ◽  
Absorption Spectra ◽  
Acid Chloride ◽  
Ethyl Esters ◽  
Methyl Mercaptan ◽  
Malonic Ester ◽  
Alcoholic Alkali ◽  
Lactam Ring

The alkaloid C15H10OSN2 occurring in the bark of Pentaceras australis Hook. f. is shown to be 4-methylthiocanthin-6-one. The lactam ring is opened by alcoholic alkali giving 2-methylthio-2-(1'-β-carbolyl)acrylic acid, followed by the elimination of methyl mercaptan and recyclization to 4-hydroxycanthin-6-one. Confirmation of the relation- ship of the alkaloid to canthinone is provided by (i) the ultraviolet absorption spectra, (ii) the formation of methyl mercaptan and 4,5-dihydrocanthine by treatment with zinc and hydrochloric acid, and (iii) the formation, by treatment with Raney nickel, of canthinone, 4,5-dihydrocanthinone, or the methyl or ethyl esters of β-carbolylpropionic acid, depending on the conditions employed. The alkaloid has been synthesized from β-carboline-1-carboxylic acid by conversion of the acid chloride with malonic ester, followed by cyclization, to 4-hydroxycanthinone, thence to 4-chlorocanthinone which with potassium methyl mercaptide yields 4-methylthiocanthinone. The low basicity of the alkaloid is discussed, particularly in relation to the basicity of 4-methoxy- canthinone.

scholarly journals Regioselective Base-induced Condensations of Acrylic Acid Derivatives

1999 ◽  
Vol 23 (3) ◽  
pp. 174-175
Author(s):  
E. Abdel-Ghani
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Dicarboxylic Acid ◽  
Ethyl Acetoacetate ◽  
Tobacco Necrosis Virus ◽  
Necrosis Virus ◽  
Antiviral Activities

The orientation of cyclization of the reaction of methyl aroylacrylate (1) and aroylacrylic acid (8) with ethyl acetoacetate and/or thiourea leading to the formation of 4-aroylmethylcyclopentane-1,3-dione (2) 5-aryl-3-oxocyclohexene-1,2-dicarboxylic acid (9), 2-imino-5-aroylmethylthiazolidin-4-one (11) and 6-aryl-2-sulfonylpyrimidine-4-carboxylic acid (14) depends on the medium employed; some compounds show moderate antiviral activities against tobacco necrosis virus.

α-CYANO-β-ARYLACRYLIC ACIDS

1945 ◽  
Vol 23b (2) ◽  
pp. 84-87 ◽  
Author(s):  
C. Y. Hopkins ◽  
Mary Chisholm ◽  
Ruth Michael
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid

α-Cyano-β-arylacrylic acids have been prepared by condensing the following aldehydes with sodium cyanoacetate: 1-naphthaldehyde, 2,3-dimethoxybenzaldehyde, 3,4-diethoxybenzaldehyde, 6-chloropiperonal, 4-isopropylbenzaldehyde, 2-acetoxy-3-methoxybenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde. The last-named gave α-cyano-β (2-hydroxy-3-methoxyphenyl) acrylic acid, which was readily converted to 8-methoxycoumarin-3-carboxylic acid.

scholarly journals Studies of Strained Ring Systems: Cyclopropa[1]Phenanthrenes

2021 ◽  
Author(s):  
◽  
Barry Roy Dent
Keyword(s):  
Carboxylic Acid ◽  
Model Compound ◽  
Structural Type ◽  
Ring System ◽  
Convincing Evidence ◽  
Conclusive Evidence ◽  
Oxidative Decarboxylation ◽  
Fluoride Ion ◽  
Allyl Cation ◽  
Dichloro Derivative

<p>The aim of the present study has been the synthesis of 1H-cyclo-Propa[1]phenanthrene (16a) and its derivatives, the sole remaining unknown structural type of the cycloproparenes. Established procedures for cycloproparene synthesis are not readily adaptable to this ring system, and routes based upon new bridge-head-substituted 1a,9b-dihydrocyclopropa[1]phenanthrenes are examined. 1, 1-Dichloro-1a-phenylseleno-1a, 9b-dihydrocyclopropa [1] phenanthrene (73) is prepared by the addition of dichlorocarbene to the corresponding phenanthrenyl selenide (72). syn-Selenoxide elimination of PhSeOH from the derived selenoxide (74) gives 1,1-dichloro-1H-cyclopropa[1]phenanthrene (76) which is intercepted by methanolysis. Labelling studies provide convincing evidence for the intermediacy of the 1H-cycloproparene. The viability of an oxidative decarboxylation route to 1,1-dialkyl-1H-cyclopropa[1]phenanthrenes is investigated for the model compound 7,7-dimethylbicyclo[4.1.0]hept-3-ene-1-carboxylic acid (122). A product of formal cyclopropyl-allyl cation rearrangement, is isolated. 1a-Methylseleno-1a,9b-dihydrocyclopropa[1]phenanthrenes (174) is prepared by the unprecedented addition of methylselenide anion to 1aH-cyclopropa[1]phenanthrene (63) (generated by a new route involving the fluoride ion-promoted elimination of the elements of chlorotrimethylsilane from the isomeric 1-chloro-1a-trimethylsilyl-1a, 9b-dihydrocyclopropa[1]phenanthrenes (170) and (171)). Treatment of the drived dimethylselenonium tetra-fluoroborate (179) with base in the presence of furan gives the endo- and exo-furan cycloadducts (180) and (181) of 1H-cyclopropa[1]phenanthrene (16a). The results presented herein provide the first conclusive evidence for the existence of the 1H-cyclopropa[1]phenanthrene ring system, both as the parent hydrocarbon (16a) and the 1,1-dichloro-derivative(76).</p>

scholarly journals 6-(Hex-5-enyloxy)naphthalene-2-carboxylic acid

2014 ◽  
Vol 70 (6) ◽  
pp. o696-o697
Author(s):  
Md. Lutfor Rahman ◽  
H. T. Srinivasa ◽  
Mashitah Mohd. Yusoff ◽  
Huey Chong Kwong ◽  
Ching Kheng Quah
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Ring System ◽  
Dihedral Angles ◽  
Carbonyl Groups ◽  
Asymmetric Unit ◽  
Compound C ◽  
Independent Molecules

The asymmetric unit of the title compound, C17H18O3, comprises three independent molecules with similar geometries. In each molecule, the carbonyl group is twisted away from the napthalene ring system, making dihedral angles of 1.0 (2), 1.05 (19)° and 1.5 (2)°. The butene group in all three molecules are disordered over two sets of sites, with a refined occupancy ratio of 0.664 (6):0.336 (6). In the crystal, molecules are oriented with respect to their carbonyl groups, forming head-to-head dimersviaO—H...O hydrogen bonds. Adjacent dimers are further interconnected by C—H...O hydrogen bonds into chains along thea-axis direction. The crystal structure is further stabilized by weak C—H...π interactions.

Nexafs Studies of Unsaturated Carboxylic Acids and Alcohols Adsorbed on the Si(111)(7×7) Surface

1986 ◽  
Vol 77 ◽  
Author(s):  
D. A. Outka ◽  
J. Stöhr ◽  
R. J. Madix ◽  
H. H. Rotermund ◽  
B. Hermsmeier ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Formic Acid ◽  
Silicon Substrate ◽  
Silicon Surface ◽  
Alcohol Group ◽  
Triple Bonds ◽  
Unsaturated Carboxylic Acids ◽  
Propiolic Acid

ABSTRACTThe adsorption of formic acid (HCOOH), acrylic acid (CH2= CHCO2H), propiolic acid (HC=CCO2H), and the corresponding alcohols on the Si(111)(7×7) surface have been investigated by NEXAFS. In each case, well-defined dipole transitions to σ* and π* molecular orbital s were observed above the C and 0 K-edges and used to probe the orientation and chemistry of these molecules on this silicon surface. Monolayer coverages of these molecules on silicon, bond strongly to the silicon surface via the carboxylic acid or alcohol group. In contrast, the C-C double and triple bonds of these molecules do not react initially with the silicon surface. Upon heating, however, the C-C double and triple bonds which are held in proximity to the surface by the carboxylic acid or alcohol group, are lost either by polymerization on the surface or reaction with the silicon substrate. These results illustrate the capabilities of NEXAFS to investigate molecular orientations on surfaces and the electronic structure of polyatomic adsorbates.

A kinetic investigation of the effects of molecular complexing on the acidities of some π donor carboxylic acids

1977 ◽  
Vol 55 (6) ◽  
pp. 1028-1038 ◽  
Author(s):  
Allan K. Colter ◽  
R. James Kersting
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Carboxylic Acids ◽  
Rate Constants ◽  
Association Constants ◽  
Second Order ◽  
Kinetic Investigation ◽  
Rate Data ◽  
Dihydroxybenzoic Acid ◽  
Order Rate

Rates of reaction of the five π donor acids indole-3-acrylic acid (IAA), indole-5-carboxylic acid (ICA), 3,4,5-trimethoxybenzoic acid (TMBA), 2,4-dihydroxybenzoic acid (DHBA), and 3,4,5-trihydroxybenzoic acid (THBA) with 4-chlorodiphenyldiazomethane (4-ClDDM) in ethanol at 30 °C were measured in the presence of the π acceptors 1,3,5-trinitrobenzene (TNB), benzotrifuroxan (BTF), and 1,2,4,5-tetracyanobenzene (TCNB) and in the absence of acceptor. For 12 of the 13combinations studied, added acceptor produced rate enhancements. The rate data were combined with independently-determined 1:1 acceptor – donor acid association constants to obtain second-order rate constants for reaction of the 1:1 acceptor – donor acid complexes. From the increase in the rate constant resulting from complexation, estimates of the increase in Ka(H2O, 25 °C) produced by complexation were obtained for 13 acceptor – donor acid combinations. Second-order rate constants for reaction of 4-ClDDM with 10 other carboxylic acids and p-toluenesulfonic acid in ethanol at 30°C were also measured and the pattern of reactivity shown to parallel very closely that of diphenyldiazomethane.

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