The Synthesis of 5,7-Dichlorocoumaran-3-one and Related Problems

1960 ◽  
Vol 13 (1) ◽  
pp. 95 ◽  
Author(s):  
WLF Armarego

5,7-Dichlorocoumaran-3-one has been prepared from methyl 2-hydroxy-3,5-dichlorobenzoate by a three stage synthesis. It could not be prepared by (i) intramolecular cyclization of 2,4-dichlorophenoxy- acetic acid or 2,4-dichlorophenoxyacetyl chloride or (ii) by the reaction of ω-bromo-2-hydroxy-3,5-dichloroacetophenone with bases. The reaction of 2,4-dichlorophenoxyacetic acid with phosphorus pentoxide in benzene gave 2,4-dichlorophenol, 2',4'-dichlorophenyl 2,4-dichlorophenoxyacetate, and diphenylmethane. By the use of 14C-labelled acids the methylene carbon atom of the diphenylmethane was shown to be derived from the methylene carbon atom of 2,4-dichlorophenoxyacetic acid. A possible mechanism is proposed for this reaction.

Synthesis ◽  
2021 ◽  
Author(s):  
Akira Nakamura ◽  
Kouhei Yamamoto ◽  
Ryo Murakami ◽  
Norihito Kawashita ◽  
Kouichi Matsumoto ◽  
...  

A method for synthesizing six-membered heterocyclic compounds was developed based on the features of O,P-acetals. Sequential reactions of intramolecular cyclization between the methylene carbon atom of O,P-acetal and its electrophilic functional group (ester or protected carbamate) was followed by Horner-Wadsworth-Emmons (HWE) olefination with various aldehydes. The developed one-pot method yielded isochroman-4-one and benzoxazin-3-one derivatives with an alkylidene moiety.


1976 ◽  
Vol 59 (5) ◽  
pp. 1097-1100
Author(s):  
Norio Hazemoto ◽  
Naoki Kamo ◽  
Yonosuke Kobatake

Abstract An electrode responsive to 2,4-D (2,4-dichlorophenoxy acetic acid) was constructed by dissolving tetrazolium derivatives as an ion exchanger in a liquid membrane. The electrode exhibited rapid and Nernstian response to solutions of 2,4-D over the concentration range 10−1 to 10−4M. The presence of diverse substances such as acetate, benzoate, and 3-indoleacetate showed no appreciable effect on the electromotive force of the electrode.


2015 ◽  
Vol 44 (1) ◽  
pp. 123-132
Author(s):  
J. Zakrzewski

Growth response of <i>Pinus silvestris</i> hypocotyl sections to some synthetic growth regulators and related substances was studied. Elongation of hypocotyl sections was stimulated by naphtaleneacetic acid, indole-3-acetic acid, in-dole-3-propionic acid, indole-3-butyric acid, 2,4-dichlorophenoxyacetic acid, indoleaoetic amide, indoleacetic nitrile and coumarin. Indole-3-acetic acid and naphtaleneacetic acid extended period of growth up to 16 and 24 hours, respectively. Growth was inhibited by kinetin, trans-cinnamic acid and 2,3,5-tri-iodobenzoic acid. No effect of gibberellic acid, tryptophan and biotin was observed.


Author(s):  
Alex G. Alexander

Indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid, and maleic hydrazide were applied as foliar sprays to 10-week-old sugarcane plants during initial studies of the interrelationships of growth-regulating materials with the sugar-metabolizing enzymes of sugarcane. Leaf samples were harvested at 1, 3, 9, and 27 days following treatment for sugar and enzyme assays. Sugar analyses were run for total ketoses, sucrose, fructose, and total reducing sugars, with glucose being determined by calculation. A series of acid phosphatase assays were conducted using as substrates the following compounds: ß-glycerophosphate, adenosinetriphosphate, uridine diphosphate glucose, glucose-1-phosphate, glucose-6-phosphate, fructose-6- phosphate, fructose-1,6-diphosphate, and 3-phosphoglyceric acid. Additional enzymes included invertase, amylase, hexokinase, phosphohexose isomerase, aldolase, triosephosphate dehydrogenase, phosphoglyceryl kinase, condensing enzyme, isocitric acid dehydrogenase, transaminase, peroxidase, and glucose oxidase. All enzyme preparations consisted of dialyzed water-soluble protein extracted from freeze-dried leaf tissue and precipitated with ammonium sulfate between 35 and 95 percent of saturation.


1997 ◽  
Vol 35 (4) ◽  
pp. 31-39 ◽  
Author(s):  
María I. Cabrera ◽  
Carlos A. Martín ◽  
Orlando M. Alfano ◽  
Alberto E. Cassano

The intrinsic kinetics of the photochemical decomposition of 2,4-dichlorophenoxyacetic acid in aqueous solution has been studied using light of 253.7 nm. Experiments were carried out in a well stirred batch reactor irradiated from its bottom by means of a tubular lamp and a parabolic reflector. Results were analyzed in terms of a very simple kinetic expression. Absorbed radiation effects were duly quantified by means of a one-dimensional radiation field model. This approach incorporates a variable absorption coefficient that is a function of the 2,4-D conversion. The decomposition kinetics can be properly represented with a point valued equation of the following form: RD, λ = − ΦD,λ eλ(y).


1982 ◽  
Vol 60 (12) ◽  
pp. 2547-2555 ◽  
Author(s):  
Gaëtan Harvais

A new medium for growing Cypripedium reginae Walt. axenically from seed was designed. Liquid culture proved unsuitable, hence a 1% agar medium supplemented with 5% potato extract was used to investigate optimal mineral element, vitamin, amino acid, sugar, and growth regulator supplements for germination, and subsequent growth. A modified Pfeffer solution with 1400 mg/L NH4NO3 + 19 mg/L ammonium citrate + 2% dextrose + 10 mg/L niacin + 5 mg/L calcium pantothenate + 5 mg/L thiamine HCl + 1 mg/L kinetin + 0.1 mg/L α-naphthaleneacetic acid gave best germination and growth to 2 years with little or no phenolic production. Gamborg's B5 medium and Murashige–Skoog (MS) medium were less than optimal when tested against the above medium. Growth regulators were more active when sterilized by membrane filtration instead of autoclaving. Of the three aminopurines tested, kinetin, benzylaminopurine (BAP), and 6(γ,γ-dimethylallylamino) purine (γγ), the order of activity was initially γγ → BAP → kinetin, but kinetin produced better greening of protocorms and plantlets, and eventually greater survival. Hence, it was chosen for further study. The auxins indole-3-acetic acid (IAA), naphthalene acetic acid (NAA), indole-3-butyric acid (IBA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were also tested alone and in combination with the aminopurines. They did not stimulate germination, but improved growth and survival when combined with aminopurines. The most active of the auxins were NAA → IAA → IBA → 2,4-D. A kinetin:NAA ratio of 10:1 was very satisfactory.


1968 ◽  
Vol 106 (1) ◽  
pp. 185-192 ◽  
Author(s):  
A. Gajdos ◽  
M. Gajdos-Török ◽  
A. Gorchein ◽  
A. Neuberger ◽  
G. H. Tait

1. ATP, GTP, CTP and UTP at concentrations of 1mm markedly decrease the amount of coproporphyrin excreted by Rhodopseudomonas spheroides illuminated in a medium containing glycine, succinate and fumarate. 2. The effect of ATP is decreased if ethionine is also added to the medium. 3. Evidence is presented showing that ATP is taken up by the organisms from the medium. 4. ATP is shown to have a marked effect on the utilization of glycine. In the presence of ATP the incorporation of the methylene carbon atom of glycine into the fatty acid moieties of the phospholipids is greatly increased, and more of the carboxyl carbon atom is lost, probably as carbon dioxide. 5. ATP has little effect on the utilization of succinate or fumarate. 6. The possible significance of these results with regard to the control by ATP of porphyrin synthesis and excretion and glycine metabolism is discussed.


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