Synthesis of 3′,4′‐disubstituted terthiophenes. Characterization and electropolymerization. I. 3′,4′‐dibromo‐2,2′:5′,2″‐terthiophene in photovoltaic display

Recent studies on conducting polymers have demonstrated that polymers of 3‐substituted thiophene produce very stable compounds. Although this kind of substitution improves the regularity, structural defects still exist. To overcome this drawback, the polymerization of 3,4‐disubstituted thiophene is proposed as a convenient way of synthesizing regular, highly conjugated conductive polymers. Our interest is thus focused on the synthesis of tetra‐substituted thiophene derivatives, their polymerization, electrochemical properties, spectral characteristics, oxidizing potential, and the feasibility of photocells development. In this article, we report the synthesis and characterization of 3′,4′‐dibromo‐2,2′:5′,2″‐terthiophene which, as such or modified, may be a good starting product for obtaining new monomers of 3′,4′‐disubstituted terthiophenes, that would allow the effect of the substituents on the properties of the respective polymers to be studied. In addition, the monomer was electropolymerized and the resulting deposit was electrochemically and morphologically characterized. Two conclusions were drawn: first, more uniform and homogeneous layers than those of polythiophene are obtained; second, the thin layers of the polymer, electron acceptors, absorb in the visible. Finally, photocells were assembled to investigate their photovoltaic effect. Although the so prepared solar cells showed some photovoltaic effect, the yield was low.© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5314–5321, 2006     

Katalysatoren des Leuna Werkes 1945 – 1988: Von der Empirie zur Wissenschaft. Teil III: Hydroraffinationskatalysatoren

Focus of the two preceding papers within this publication series were the development and manufacturing of technical catalysts at the Leuna Werke company from 1921 – 1945 (part I) and 1950 – 1991 (part II) for the reforming and isomerization catalysts. This article describes the genesis of the hydrofining group of catalysts as cornerstones of the GDR economy. 36 catalysts and 15 special aluminum oxides, X‐ray amorphous as well as crystalline aluminum silicates, were developed and brought into service for the Leuna hydrogenation and other refineries. During that time, a vast knowledge base was generated; new chemical processes were pioneered and equipped with tailor‐made catalysts developed in Leuna.     

Crystallography and Structure–Property Relationships in 2,2′,2″,2′′′,4,4′,4″,4′′′,6,6′,6″,6′′′‐Dodecanitro‐1,1′ : 3′1″ : 3″,1′′′‐ Quaterphenyl (DODECA)

X‐ray crystallographic study of 2,2′,2″,2′′′,4,4′,4″,4′′′,6,6′,6″,6′′′‐dodecanitro‐1,1′ : 3′1″ : 3″,1′′′‐quaterphenyl (DODECA) has been carried out. Nonbonding interatomic distances of oxygen atoms inside of all the nitro groups are shorter than those corresponding to the intermolecular contact radii for oxygen. By means of the DFT B3LYP/6‐31(d, p) method a difference of 136 kJ mol⁻¹ between the X‐ray and DFT structures of DODECA was found. The bearer of the highest initiation reactivity in its molecule in solid phase should be the nitro group at 4′′′‐position, in contrast to those at 2′‐ or 2″‐positions in its isolated molecule. The most reactive nitro group in the DODECA molecule can be well specified by the relationship between net charges on nitro groups and charges on their nitrogen atoms, both of them for the X‐ray structure. The ¹⁵N chemical shift, corresponding to this nitro group for the initiation by impact and shock, correlates very well with these shifts of the reaction centers of the other six “genuine” polynitro arenes.     

Katalysatoren des Leuna Werkes von 1960 – 1986: Von der Empirie zur Wissenschaft. Teil IV: Hydrospaltkatalysatoren

The historic development of technical catalysts at the Leuna chemical site is shown in a series of four articles. Although the research resulted in more than 300 patents, this paper does not intent to constitute a formula for success for the development of new catalysts. Instead, it aims at highlighting the remarkable and internationally recognized accomplishments of the Leuna R&D teams in the field of catalyst and process development from the 1950s until the late 1980s. In addition to the the economic value of hundreds of millions of Mark (the GDR currency), an significant result of these R&D activities was a much more elaborated concept on the properties and mode of action of technical catalysts. Part 4 looks at hydrocracking catalysts and the corresponding industrial processes developed in the former GDR.     

Katalysatoren des Leuna Werkes 1945 – 1991: Von der Empirie zur Wissenschaft. Teil II: Reformier‐ und Isomerisierungskatalysatoren

Subject of the first part of this publication series was the development and manufacturing of technical catalysts within the Leuna Werke company from 1921 – 1945. Part II as well as part III and IV will focus on this topic as well, looking at the years from 1945 to 1991. Within this timeframe, a high‐performing research and development as well as an efficient production line for new catalysts was implemented, facing a new and challenging macroeconomic environment. In recognition of the fact that the first newly developed catalyst after WW II was a reforming catalyst, this article will describe the development path of this group of catalysts as well as the closely related isomerization catalysts.     

Mikroverfahrenstechnik: Komponenten – Anlagenkonzeption – Anwenderakzeptanz – Teil 3

Microtechnology: Components – Plant Concepts – User Acceptance Many activities over the last five or so years have focussed on the thus far underdeveloped field of carrying out reactions on small scales. Due to the rapid development of new components, this paper touches on recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous size difference between the microchannels and the fluid periphery of possible components this is not just a technical question, it touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development, are questions that are addressed here with respect to the big industrial interest in microreactors.     

Mikroverfahrenstechnik: Komponenten – Anlagenkonzeption – Anwenderakzeptanz – Teil 2

Microtechnology: Components – Plant Concepts – User Acceptance Many activities over the last five or so years have focussed on the thus far underdeveloped field of carrying out reactions on small scales. Due to the rapid development of new components, this paper touches on recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous size difference between the microchannels and the fluid periphery of possible components this is not just a technical question, it touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development, are questions that are addressed here with respect to the big industrial interest in microreactors.     

Discovery of 5′′‐Chloro‐N‐[(5,6‐dimethoxypyridin‐2‐yl)methyl]‐2,2′:5′,3′′‐terpyridine‐3′‐carboxamide (MK‐1064): A Selective Orexin 2 Receptor Antagonist (2‐SORA) for the Treatment of Insomnia

The field of small‐molecule orexin antagonist research has evolved rapidly in the last 15 years from the discovery of the orexin peptides to clinical proof‐of‐concept for the treatment of insomnia. Clinical programs have focused on the development of antagonists that reversibly block the action of endogenous peptides at both the orexin 1 and orexin 2 receptors (OX₁R and OX₂R), termed dual orexin receptor antagonists (DORAs), affording late‐stage development candidates including Merck’s suvorexant (new drug application filed 2012). Full characterization of the pharmacology associated with antagonism of either OX₁R or OX₂R alone has been hampered by the dearth of suitable subtype‐selective, orally bioavailable ligands. Herein, we report the development of a selective orexin 2 antagonist (2‐SORA) series to afford a potent, orally bioavailable 2‐SORA ligand. Several challenging medicinal chemistry issues were identified and overcome during the development of these 2,5‐disubstituted nicotinamides, including reversible CYP inhibition, physiochemical properties, P‐glycoprotein efflux and bioactivation. This article highlights structural modifications the team utilized to drive compound design, as well as in vivo characterization of our 2‐SORA clinical candidate, 5′′‐chloro‐N‐[(5,6‐dimethoxypyridin‐2‐yl)methyl]‐2,2′:5′,3′′‐terpyridine‐3′‐carboxamide (MK‐1064), in mouse, rat, dog, and rhesus sleep models.