The synthesis of a linear tröger's base derived from naphthalene: 7H‐15H‐6,14‐methanodinaphtho[2,3‐b:2′,3′‐f][1,5]diazocine

The title compound 3 was prepared in four steps from commercial 3‐amino‐2‐naphthoic acid in an overall 75 % yield. Attempts to use the same approach in the case of 2‐aminonicotinic acid methyl ester failed. All the compounds were characterized by NMR.     

Synthesis and anti‐staphylococcal activity of new halogenated pyrroles related to Pyrrolomycins F

The chemical synthesis of new halogenated pyrroles related to pyrrolomycins F is described and the anti‐staphylococcal activity compared. The replacement of 4′‐bromo atom of parent compounds with two chloro atoms at 3′ and 5′ position increase the antibacterial activity against a reference strain of S. aureus.     

Photodegradation of 2‐mercaptobenzothiazole disulfide and related benzothiazoles

The photodegradation of 2‐mercaptobenzothiazole disulfide, 2‐mercaptobenzothiazole and benzothia‐zole was investigated. Benzothiazole was found to undergo photodimerization into 2,2′‐bibenzothiazole, and in the presence of oxygen to give two additional photoproducts ‐ 2‐hydroxybenzothiazole and 2‐methylbenzothiazole. The major degradation products of 2‐mercaptobenzothiazole are benzothiazole and 2‐benzothiazolesulfonic acid, with 2,2′‐thiobisbenzothiazole and 2‐mercaptobenzothiazole disulfide as the minor degradation products. Direct photolysis of 2‐mercaptobenzothiazole disulfide gave 2‐mercapto‐benzothiazole and in acetonitrile 2‐thiocyanatobenzothiazole was also detected. A mechanism is proposed to rationalize the formation of photodegradation products.     

Synthesis of N‐benzoylamino‐1,2,3,6‐tetrahydropyridine derivatives as potential anti‐inflammatory agents

N‐Benzoylamino‐1,2,3,6‐tetrahydropyridines 9a‐q were synthesized from 4‐substituted pyridines in four steps. Amination of pyridines was carried out to prepare intermediate N‐aminopyridinium mesylates using mesytelenesulfonyl hydroxmate (MSH) as aminating agent. N‐aminopyridinium mestylates reacted with appropriately substituted acyl chlorides to form N‐ylides as stable crystalline solids. Partial reduction of N‐ylides with mild reducing agent afforded N‐benzoylamino‐1,2,3,6‐tetrahydropyridines in fair to good yields.     

Synthesis and anti‐HIV activity of n‐(3‐amino‐3,4‐dihydro‐4‐oxopyrimidin‐2‐yl)‐4‐chloro‐2‐mercapto‐5‐methylbenzenesulfonamide derivatives

A series of N‐(3‐amino‐3,4‐dihydro‐4‐oxopyrimidin‐2‐yl)‐4‐chloro‐2‐mercapto‐5‐methylbenzenesulfonamide derivatives 10‐17 have been synthesized as potential anti‐HIV agents. The in vitro anti‐HIV‐1 activity of these compounds has been tested at the national Cancer Institute (Bethesda, MD), and the structure‐activity relationships are discussed. The selected N‐[3‐amino‐3,4‐dihydro‐6‐(tert‐butyl)‐4‐oxothieno[2,3‐e]pyrimidin‐2‐yl]‐4‐chloro‐2‐metcapto‐5‐methylbenzenesulfonamide ( 14 ) showed good anti‐HIV‐1 activity with 50% effective concentration (EC₅₀) value of 15 μM and weak cytotoxic effect (IC₅₀ = 106 μM).     

Modeling of Nitroxide‐Mediated Semibatch Radical Polymerization

A mechanistic model is developed for high‐temperature (138 °C) styrene semibatch thermally and conventionally initiated FRP, as well as NMP with a two‐component initiating system (tert‐butyl peroxyacetate, 4‐hydroxy‐TEMPO). The model, using kinetic coefficients from literature, provides a good representation of the FRP experimental results. Implementation of a gel effect correlation to represent the change in the diffusion‐controlled termination rate coefficient with conversion improves the fit to the thermally initiated system, but is not required to represent the production of low molecular weight material ( Dalton) by conventionally initiated FRP or NMP. The low initiator efficiency found in NMP is well explained by a reaction network involving combination of free nitroxide with methyl radicals formed from initiator decomposition.

     

Practical Microwave Synthesis for Organic Chemists.Strategies,Instruments, and Protocols. Edited by C. Oliver Kappe,Doris Dallinger and Shaun Murphree.

Wiley‐VCH, Weinheim 2008. 300 pp., hardcover € 59.00.—ISBN 978‐3527320974

     

A facile rearrangement of pyrroloindoline derivative to pyrroloquinoline: A new analogues of duocarmycins

Free‐radical generated at C‐7 position of indole derivative bearing N‐(3′‐chloroallyl) group prompted a regioselective intramolecular cyclization to furnish pyrroloindoline derivative, through the more favorable 5‐exo‐trig cyclization mode. The pyrroloindoline compound smoothly rearranged to pyrroloquinoline under mild conditions.     

Synthesis of thiazolo[3,2‐d][1,2,4] triazines through palladium‐catalyzed heteroannulation of acetylenic compounds

The reaction of 6‐methyl‐5‐(prop‐2‐ynylthio)‐5,6‐dihydro‐1,2,4‐triazin‐3(4H)‐one 1 with various iodobenzenes 2 in the presence of palladium catalyst leads to the formation of substituted triazolotriazines.