575-37-1Relevant articles and documents
Synthesis and spectroscopic properties of 4a,14a-diazoniaanthra[1,2-a] anthracene and 13a,16a-diazoniahexaphene derived from 1,7-dimethylnaphthalene
Granzhan, Anton,Bats, Jan W.,Ihmels, Heiko
, p. 1549 - 1555 (2006)
An improved preparation of 1,7-dimethylnaphthalene is presented, which is used as a precursor for the synthesis of diazoniahexacyclic salts, namely, 4a,14a-diazoniaanthra[1,2-a]anthracene (3) and 13a,16a-diazoniahexaphene (7). The influence of the reaction conditions on the formation of these isomers was investigated. Notably, the selectivity of the reactions depends significantly on the acid employed in the cyclization step. Both compounds exhibit similar absorption and fluorescence emission properties. Compound 3 exhibits a remarkable photopersistence in the solid state and in air-saturated aqueous solutions. However, diazoniahexaphene 7 undergoes rapid photodegradation in solution. X-ray diffraction analysis reveals that compound 3 adopts a helicene structure in the crystalline state. Georg Thieme Verlag Stuttgart.
Methylation of 2-methylnaphthalene over metal-impregnated mesoporous MCM-41 for the synthesis of 2,6-triad dimethylnaphthalene isomers
Niftaliyeva, Aysel,Güle?, Fatih,Karaduman, Ali
, p. 2403 - 2416 (2020/02/11)
2,6-Dimethylnaphthalene (2,6-DMN) is one of the key intermediates for the production of polyethylene naphthalate (PEN), which demonstrates superior properties compared with the polyethylene terephthalate. However, the complex synthesis procedure of 2,6-DMN increases the production cost and decreases the commercialisation of PEN. In this study, selective synthesis of 2,6-triad DMN isomers (1,5-DMN, 1,6-DMN and 2,6-DMN) has been investigated by the methylation of 2-methylnaphthalene (2-MN) over mesoporous Cu/MCM-41 and Zr/MCM-41 zeolite catalysts. On the contrary of other DMN isomers, 2.6-triad isomers can effectively be converted to be profitable 2,6-DMN with an additional isomerisation reaction, which is a new approach to reach higher 2,6-DMN yield. The methylation reactions of 2-MN were investigated in a fixed-bed reactor at 400?°C and weight hourly space velocity of 1–3?h?1. The results showed that the activity of MCM-41 on the methylation of 2-MN has been enhanced with the impregnation of Cu. The conversion increased from about 17% to 35 wt% with the impregnation of Cu. Similarly, the 2,6-triad DMN selectivity and 2,6-/2,7-DMN ratio reached the maximum level (48 wt% and 1.95, respectively) over Cu-impregnated MCM-41 zeolite catalyst.
Conversion of propionic acid and 3-pentanone to hydrocarbons on ZSM-5 catalysts: Reaction pathway and active site
Wang, Xuefen,Ding, Shuang,Wang, Hua,Liu, Xiao,Han, Jinyu,Ge, Qingfeng,Zhu, Xinli
, p. 79 - 89 (2017/08/03)
Conversion of propionic acid to gasoline-range molecules was investigated at 350?°C on a series of ZSM-5 catalysts with varying density of Br?nsted acid sites (BAS), achieved by ion exchange of proton with Na+. Ketonization of propionic acid to 3-pentanone is the primary reaction, with the sequential aldol condensation to dipentanone alcohol being the secondary. The major reaction pathway for forming the aromatics involves dehydration, cyclization, dehydration and hydride transfer from dipentanone alcohol, leading to the formation of C10 aromatics before being dealkylated to lighter aromatics. Temperature programmed desorption of propionic acid indicates that the reaction initiates with acylium cation formation on BAS through dehydration. Comparing the turnover frequencies of ketonization and aldol condensation on ZSM-5 with varying density of BAS indicates that BAS is the active site for both reactions. The propionic acid feed deactivates the catalyst faster than the 3-pentantone feed due to a stronger adsorption of propionic acid on the acid sites of ZSM-5.
