1567-75-5Relevant articles and documents
Pentazocine prodrug as well as preparation method and application thereof
-
Paragraph 0040; 0046-0047; 0080; 0087-0088, (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.
Mechanistic organic chemistry in a microreactor. Zeolite-controlled photooxidations of organic sulfides
Clennan, Edward L.,Zhou, Wenhui,Chan, Jacqueline
, p. 9368 - 9378 (2007/10/03)
The intrazeolite and solution photooxygenations of a series of sulfides have been compared. The unusual zeolite environment enhances the rates of reaction, it suppresses the Pummerer rearrangements, and it has a dramatic effect on the sulfoxide/sulfone ratio. A detailed kinetic study utilizing trapping experiments and intramolecular competition provides evidence for cation complexation to a persulfoxide intermediate as the underlying phenomenon for the unique intrazeolite behavior. For example, the enhanced rate of reaction is traced to the cation stabilization of the persulfoxide toward unproductive decomposition to substrate and triplet oxygen.
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.
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.
Deamination Reactions, 42. Addition of Diazocyclopropanes to Carbonyl Compounds
Kirmse, Wolfgang,Hellwig, Georg,Chiem, Pham van
, p. 1511 - 1524 (2007/10/02)
Diazocyclopropanes (6, 38, 57) were generated in equilibrium with cyclopropanediazonium ions by base-induced cleavage of the analogous nitrosoureas in methanol.Efficient trapping of the diazocyclopropanes occurred in dilute solution with a slight excess of carbonyl compounds.The reactivity of the resulting 1-(α-hydroxyalkyl)cyclopropanediazonium ions (10) depended strongly on the α-substituents.Pinacol rearrangements predominated with aldehyde adducts, the migratory aptitudes being H > Ph > CH3.These 1,2-shifts are thought to proceed with inversion at the terminus - the preferred exo-attack of acetaldehyde at 7-diazonorcarane (38) led to the endo-ketone 40.The major product derived from the acetone adduct 22 was the epoxide 26 whose reaction(s) with metanol were also examined.The intramolecular addition of 8-diazobicyclooctan-4-one (57) gave rise to 6-methoxybicyclooct-4-en-1-ol (60).Due to steric constraints, the intermediate 58 underwent exclusive cyclopropyl-allyl transformations (otherwise a minor reaction).
Attempted Halogen Exchange in Methyl Substituted Mono- and Dibromocyclobutanes
Hittich, Reinhard,Mach, Helmut,Griesbaum, Karl
, p. 2738 - 2747 (2007/10/02)
Reactions of AgBF4 with 1-bromo-1-methyl- (1a) and with 1,3-dibromo-1,3-dimethylcyclobutanes (2a, 3a) afforded a partial of complete exchange of bromine for fluorine, depending on the reactant ratios.In 1,3-dibromo-1,2-dimethyl- (4a - 7a) and in 1,2-dibromo-1,2-dimethylcyclobutanes (8a), however, only one bromine substituent was exchanged for fluorine.From 8a products having cyclopropane structures (9, 10) and acyclic dihalo compounds (11a, b) were also formed.Reactions of SbCl5 with 1,3-dibromo-1,3-dimethylcyclobutane (2a, 3a) afforded a complete, reactions with 1,3-dibromo-1,2-dimethyl- (7a) and with 1.2-dibromo-1,2-dimethylcyclobutane (8a), however, only a partial exchange of bromine for chlorine.From 8a acyclic products were additionally formed.
VINYL MIGRATION IN THE OXYTHALLATION OF SOME 1,3-DIENES
Murakami, Masashi,Nishida, Shinya
, p. 997 - 1000 (2007/10/02)
The oxythallation of certain 1,3-dienes with thallium (III) nitrate trihydrate in MeOH-CH2Cl2 at 0-20 deg C gave products after vinyl migration .Methyl 1-methylcyclopropyl ketone, obtained in the reaction of 2,3-dimethyl-1,3-butadiene, was presumably derived from a cyclopropylmethyl cation, an intermediate in the vinyl migration.
Wanderungstendenzen cyclischer, polycyclischer und methylverzweigter Alkylreste bei der Beckmann-Umlagerung
Langhals, Heinz,Ruechardt, Christoph
, p. 3831 - 3854 (2007/10/02)
The migration aptitudes of polycyclic bridgehead groups, cycloalkyl groups as well as of β-, γ- and δ-branched alkyl groups in the Chapman variant of the Beckmann rearrangement were determined.From these data it is concluded that at transition state 2 the migrating group is not resembling a planarised carbenium ion R+, but rather a pentacoordinated carbonium ion structure.Because only small geometrical changes occur in the migrating group vertical stabilisation of charge at transition state is believed to have significant influence on the migration aptitudes.