1123-19-9Relevant academic research and scientific papers
Pentazocine prodrug as well as preparation method and application thereof
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Paragraph 0040-0043; 0078-0080; 0082-0084; 0111-0112, (2020/07/15)
The invention discloses a pentazocine prodrug shown as a formula (I), a preparation method thereof and medical application of a pharmaceutical preparation containing the pentazocine prodrug, wherein Ris hydrogen or deuterium. The water solubility of the prodrug compound is improved by 20 times or above at room temperature, the prodrug compound is chemically stable, the onset time is delayed, thedrug effect is prolonged, meanwhile, the same parent drug blood concentration is generated at a low dosage, and the prodrug compound has a wide clinical application prospect.
Preparation method of pentazocine intermediate
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Paragraph 0095-0097; 0116-0117; 0127-0128, (2019/04/04)
The invention discloses a preparation method of a pentazocine intermediate and belongs to the technical field of chemical synthesis. A compound 11, namely the prepared pentazocine intermediate, is obtained through a methylation reaction, a ring-opening reaction, a reduction reaction, a protection reaction, a substitution-reduction reaction, an esterification reaction, an elimination reaction, a hydrazinolysis reaction, a ring-closing reaction and a condensation-demethylation reaction. The problems of low yield and resource waste in existing pentazocine preparation methods are solved, the current situation that industrial production is difficult to realize due to use of explosion substances and high pressure condition is eliminated, the key intermediate is obtained with a simple method, themethod is high in yield, simple in process and applicable to industrial production, resources are saved, and the production cost is reduced.
A new 2H-azirin-3-amine as a synthon for 2-methylaspartate
Brun, Kathrin A.,Heimgartner, Heinz
, p. 2951 - 2959 (2007/10/03)
The synthesis of a novel 2,2-disubstituted 2H-azirin-3-amine 3a as a building block for racemic Asp(2Me) is described. This synthon contains an ester group in the side chain. The reaction of 3a with thiobenzoic acid and the amino acid Z-Val-OH yielded the racemic monothiodiamide 10a and the dipeptide 11 as a mixture of diastereoisomers, respectively (Scheme 2). In 11, each of the protecting groups was removed selectively (Scheme 3). First attempts toward the preparation of enantiomerically pure synthons for Asp(2Me) with a chiral auxiliary group in the side chain are described. Synthons 3b with a 1-(naphthalen-1-yl)ethyl ester group and 3c with a menthyl ester group were prepared and reacted with thiobenzoic acid to form monothiodiamides 10b and 10c (Scheme 2). However, the diastereoisomers of the synthons 3b and 3c could not be separated by chromatography.
Synthesis of the bis-spiroacetal moiety of the polyether antibiotic CP44,161
Allen, Paul R.,Brimble, Margaret A.,Prabaharan, Hishani
, p. 379 - 389 (2007/10/03)
The syntheses of bis-spiroacetals 25a, 25c and 40 which constitute the central framework of the polyether antibiotic CP44,161 4, are described. The tricyclic bis-spiroacetal ring is formed by oxidative cyclisation of hydroxyspiroacetal 9 which in turn is assembled from lactone 10 and acetylene 11. The key stereogenic centres in acetylene 11 were assembled using a Sharpless asymmetric dihydroxylation and an Evans asymmetric alkylation of a chiral oxazolidinone. Asymmetric dihydroxylation of alkene 14 using (DHQ)2PHAL (hydroquinine phthalazine-1,4-diyl diether) led to acetylene 22 which in turn was converted to bis-spiroacetals 25a and 25c. Construction of the isomeric acetylene 11 was effected via Sharpless asymmetric dihydroxylation of alkene 14 using the pseudoenantiomeric chiral ligand (DHQD)2PHAL which in turn led to the formation of bis-spiroacetal 40 with the same configuration at C-2 as that present in antibiotic CP44,161 4. Barbier addition of bromide 8 to bisspiroacetal aldehyde 27 afforded alcohol 28 which was then converted to polyethers 32 and 33 via an epoxidation cyclization strategy. This latter reaction sequence demonstrated the feasibility of appending the E ring to the tricyclic bis-spiroacetal BCD ring system of antibiotic CP44,161 4.
Selective Alkylation of β-Ketoester Enolates using O-Methyl Aminosulfoxonium salts; the First Example of C-alkylation using Sulfoxonium Salt Electrophiles
Pickersgill, I. Fraser,Marchington, Allan P.,Rayner, Christopher M.
, p. 2597 - 2598 (2007/10/02)
The alkylation of β-ketoester enolates with O-methyl aminosulfoxonium tetraphenylborate salts is reported; good to excellent selectivity for C- vs.O-alkylation is observed, and is found to be dependent on the nature of the β-ketoester, solvent, metal counterion and aminosulfoxonium salt.
Grignard Addition Reactions to 1,4-Difunctionalized But-2-ynes
Silva, Anthony N. De,Francis, Craig L.,Ward, A. David
, p. 1657 - 1672 (2007/10/02)
Trisubstituted alkenes of E geometry have been prepared by anti addition of Grignard reagents to 1,4-difunctionalized but-2-ynes.Addition of primary, secondary and aromatic Grignard reagents to but-2-yne-1,4-diol provided (E)-2-substituted but-2-ene-1,4-diols as major products along with the corresponding 2-substituted buta-2,3-dien-1-ols.Addition of phenylmagnesium bromide to the mono- and di-methyl ethers of but-2-yne-1,4-diol gave 2,3-diphenyl-1,3-diene.Treatment of 4-dimethylaminobut-2-yn-1-ol with primary alkyl and alkenyl Grignard reagents afforded the 2-substituted anti addition product regiospecifically, stereospecifically and in high yield.Reaction of 1-dimethylamino-4-methoxybut-2-yne with butylmagnesium bromide provided only the 3-substituted anti addition product in good yield.
La reaction d'ω-azidocetones avec la triphenylphosphine: une voie d'acces generale aux imines cycliques
Vaultier, M.,Lambert, P. H.,Carrie, R.
, p. 83 - 92 (2007/10/02)
The ω-azidoketones RC(=O)-CH(R')-(CH2)n-CH(R'')-N3 react with triphenylphosphine in anhydrous media to give 5, 6 and 7 membered cyclic imines via an intramolecular aza-Wittig reaction with good yields.A general synthesis of ω-haloketones which are the precursors of the azidoketones was also devised.
SYNTHESIS OF SINGLE ISOMERS (E OR Z) OF PROTECTED γ,δ-UNSATURATED KETONES BY THE HORNER-WITTIG REACTION
Cornish Christopher A.,Warren, Stuart
, p. 2585 - 2598 (2007/10/02)
The lithium derivative of the γ-diphenylphosphinoyl ketal (10a) added to aldehydes and ketones to give stable Horner-Wittig intermediates (11) which were separated and converted into single isomers (E or Z) or γ,δ-unsaturated ketals (12). erythro-Adducts (11) and hence Z-(12), were selectively formed by addition of aldehydes and threo adducts (11), and hence E-(12), by reduction of the corresponding α-diphenylphosphinoyl ketones (13), prepared by acylation of the same γ-diphenylphosphinoyl ketal (10a).
Reinvestigation of the Stevens Rearrangement of 1-Benzyl-1,3,4-trimethyl-1,2,5,6-tetrahydropyridinium Salts II. Synthesis of 2-Aryl-3-isopropenyl-1,3-dimethylpyrrolidines
Bosh, Joan,Rubiralta, Mario
, p. 485 - 494 (2007/10/02)
cis-2-Aryl-3-isopropenyl-1,3-dimethylpyrrolidines IIa and IIb have been synthesized by an unambiguous way, thus confirming the structure of the methylene derivatives obtained as by-products in the Stevens rearrangement of 1-benzyl-1,3,4-trimethyl-1,2,5,6-tetrahydropyridinium salts Ia and Ib.The synthesis is based on the acid-induced intramolecular cyclization between an iminium salt and the α-position of a ketal group.Thus, condensation between amino ketal XXI, prepared via Gabriel synthesis from 5-chloro-3-methyl-2-pentanone, and the appropriate aldehyde afforded imines XXI.Their treatment with dry hydrogen chloride followed by acid hydrolysis and methylation gave 3-acetylpyrrolidines IV, which were transformed into the isopropenyl derivatives II by reaction with methyl-lithium and further dehydration.
