92471-86-8Relevant academic research and scientific papers
Efficient halogenation synthesis method of aryl halide
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Paragraph 0206-0210, (2021/03/31)
The invention discloses an efficient halogenation synthesis method of aryl halide. The method comprises the following step: in the presence of a catalyst (sulfoxide or oxynitride), a halogenation reagent and a solvent, carrying out a halogenation reaction on an aromatic ring compound to obtain the aryl halide. According to the present invention, in the presence of a catalyst (sulfoxide or nitrogenoxide), a halogenation reagent and a solvent, the aromatic ring is subjected to an efficient halogenation reaction, such that the very useful aryl halide can be obtained with high activity and high selectivity; and by adopting the method disclosed by the invention, aryl halides can be efficiently synthesized, and the method has a wide application prospect in actual production.
Asymmetric synthesis of iridoid derivatives using resolved 2-phenylindoline as a chiral auxiliary
Santangelo, Ellen M.,Liblikas, Ilme,Mudalige, Anoma,Toernroos, Karl W.,Norrby, Per-Ola,Unelius, C. Rikard
experimental part, p. 5915 - 5921 (2009/05/27)
An asymmetric synthetic route to cis,cis-nepetalactol (component of the sex pheromone for the hop aphid, Phorodon humuli) is presented. 2-Phenylindoline was resolved to provide a chiral auxiliary for the cycloaddition of oxocitral. The resolution was made by chromatographic separation of the diastereomers of the urea derivative made from 2-phenylindoline and with (R)-(+)-α- methylbenzyl isocyanate, followed by reductive cleavage of the isolated diasteromers using diborane. The cycloaddition of oxocitral using (S)-2-phenylindoline yielded an enantiopure product after chromatography. Hydrolysis of the cycloaddition adduct yielded gastrolactol (3). As gastrolactol is a versatile synthon for the synthesis of iridoids, the overall procedure provides a general asymmetric route to elaborated iridoids. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
Photochemical Rearrangement of α-Chloro-Propiophenones to α-Arylpropanoic Acids: Studies on Chirality Transfer and Synthesis of (S)-(+)-Ibuprofen and (S)-(+)-Ketoprofen
Sonawane, Harikisan,Bellur, Nanjundiah S.,Kulkarni, Dilip G.,Ayyangar, Nagaraj R.
, p. 1243 - 1260 (2007/10/02)
A new single-step efficient photochemical approach for α-arylpropanoic acids (4) from α-chloro-propiophenones (5) is described.It involves carbonyl triplet excited state directed 1,2-aryl migration of the aryl group which has been found to be highly dependent upon the nature of the aryl substituent.The mode of the rearrangement is probed by the study of the photobehaviour of a set of optically active α-chloro-propiophenones.The results suggest that the nature of the carbonyl triplets (n, ?*/ ?, ?*) plays an important role in the chirality transfer.This method finds application in the synthesis of optically active ibuprofen (4e) and ketoprofen (26), though in moderate optical yields.
Carboxylic acid synthesis process
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, (2008/06/13)
A process is described for preparing alpha-arylalkanoic acids, which comprises preparing and subsequently rearranging ketals of formula STR1 (in which Ar, R, R1, R2 and R4 have the meanings given in the description). The ketals of formula II are prepared from the corresponding alpha-hydroxyketals. The rearrangement reaction is conducted under mild conditions.
A UNIQUE 1,2-SHIFT SELECTIVITY IN 2-HYDROXYPROPIOPHENONE DIMETHYLACETALS: GENERATION OF NEW METHODOLOGIES FOR METHYL-2-ARYLPROPANOATES AND 1,2-CARBONYL TRANSPOSITION
Sonawane, H. R.,Nanjundiah, B. S.,Kulkarni, D. G.,Ahuja, Jaimala R.
, p. 7319 - 7324 (2007/10/02)
α-Hydroxydimethylacetals I have been shown to undergo two different rearrangements involving highly selective 1,2-shifts under mild conditions.When treated with Ph3P/CCl4 in the presence of pyridine, I were cleanly transformed via 1,2-aryl shifts into methyl 2-arylpropanoates, an important class of antiinflammatory agents; a pronounced substituent effect has been observed in this rearrangement. On the other hand, treatment of I with catalytic amount of Ph3P/I2 in benzene furnished α-methoxy-α-aryl propan-2-ones in excellent yields and culminated in the development of a new methodology for 1,2-carbonyl transposition.
Carboxylic acid synthesis process
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, (2008/06/13)
A process is described for preparing alpha-arylalkanoic acids, which comprises preparing and subsequently rearranging ketals of formula (in which Ar, R, R1, R2 and R4 have the meanings given in the description). The ketals of formula II are prepared from the corresponding alpha-hydroxyketals. The rearrangement reaction is conducted under mild conditions.
Process for preparing naproxen
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, (2008/06/13)
Process for preparing Naproxen via a sequence of stereospecific reactions which comprises: condensation of 1-chloro-2-methoxy-naphthalene with a (S)-2-halo-propionyl halide according to the Friedel-Crafts reaction, ketalization of the thus obtained (S)-2-halo-1-(5'-chloro-6'-methoxy-2'-naphthyl)-propan-1-one, rearrangement of said ketal to afford an ester, hydrolysis of the ester and removal of the chlorine atom in 5-position by hydrogenolysis. New (S) 2-halo-1-(5'-chloro-6'-methoxy-2'-naphthyl)-propan-1-ones.
Zinc Salt Catalyzed Rearrangement of Acetals of Optically Active Aryl 1-Chloroethyl Ketones: Synthesis of Optically Active 2-Arylpropionic Acids and Esters
Piccolo, Oreste,Spreafico, Franca,Visentin, Giuseppina,Valoti, Ermanno
, p. 10 - 14 (2007/10/02)
The preparation of (S)-2-(4'-isobutylphenyl)propionic acid ((S)-Ibuprofen) (82percent optical purity) and (S)-2-(6'-methoxy-2'-naphthyl)propionic acid (Naproxen) (96percent optical purity) has been accomplished by starting from optically pure (S)-2-chloropropionyl chloride.The investigation for finding the best experimental conditions and minimizing racemization phenomena is presented.
