- Preparation method of Eperisone hydrochloride impurity F
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The invention provides a preparation method of Eperisone hydrochloride impurity F, which comprises the following steps: 2-bromoethylbenzene is used as a raw material, 1- (2-ethylphenyl) propanol is obtained through Grignard reaction, 2-ethyl propiophenone is obtained through oxidation reaction, and finally the Eperisone hydrochloride impurity F is obtained through Mannich reaction of the 2-ethyl propiophenone, paraformaldehyde and piperidine hydrochloride by a one-pot method. The structure of the Eperisone hydrochloride impurity F is shown as a formula (I), the purity of theEperisone hydrochloride impurity F obtained by adopting the technical scheme provided by the invention can reach 99%, and the Eperisone hydrochloride impurity F can be used as a reference substance for experimental research.
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Paragraph 0021-0022; 0024-0025; 0027-0028
(2021/02/25)
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- An efficient MnCl2-catalyzed tandem acylation-cross-coupling reaction of o-halobenzoyl chloride with diorganyl magnesium compounds
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An efficient tandem cross-coupling reaction of o-chlorobenzoyl chloride with dialkyl and diaryl magnesium compounds in the presence of manganese (II) chloride was developed, which proceeds in good yield under mild conditions. Copyright
- Zhang, Fengmin,Shi, Zhuangzhi,Chen, Feng,Yuan, Yu
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experimental part
p. 57 - 63
(2010/10/21)
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- Regioselectivity of the Base-Induced Ring Cleavage of 1-Oxygenated Derivatives of Cyclobutabenzene
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Oxy anions 3 generated from 1,2-dihydrocyclobutabenzen-1-ones 1 through addition of a charged nucleophile or from 1-hydroxy-1,2-dihydrocyclobutabenzenes 2 by deprotonation with base lead to stable products through distal and/or proximal cleavage of the strained four-membered ring via benzyl carbanion 4 and/or aryl carbanion 5. A systematic study of this process reveals the relative stability of the two isomeric carbanions 4 and 5 as a key factor in determining the course of the ring-cleavage reaction. While benzyl carbanions 4 can be trapped with carbon electrophiles, attempts at trapping aryl carbanions 5 with electrophiles other than H+ failed. In protic solvents, the magnesium salt of the tertiary alcohol 2 shows an increased rate of proximal cleavage as compared to its alkali salts. From this, we conclude that, in contrast to benzyl carbanions 4, free aryl carbanions 5 are of transient existence only. Proximal C,C-bond cleavage seems to occur either through protonation of 5 from a fast, reversible equilibrium 3?5 in which 3 strongly predominates, or in protic solvents possibly even through a rate-limiting protonation of 3 at the aromatic C-atom, bypassing free anion 5 altogether. Thus, additional factors other than just the relative stability of isomeric carbanions 4 and 5 are of importance in determining the regiochemistry of the base-induced C,C-bond cleavage in ketones 1 and in alcohols 2.
- Gokhale, Abha,Schiess, Peter
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p. 251 - 267
(2007/10/03)
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