Absorption Spectra. II. Some Aldehyde Condensation Products of Methyl Pyridines

Abstract

Inasmuch as microscopic and X-ray examinations of the alumina catalyst showed that the laboratory-prepared alumina was more crystalline than the commercial alumina tested, it may be that the greater catalytic activity of the former is connected with its higher degree of crystallinity.The ferric chloride-Filtrol catalyst was tested at 200°( expt. 28) and at 300°( expt. 29). Hydrogen chloride was evolved initially at both temperatures but no toluene was produced. The iron in the used catalysts was at least 95% in the ferrous state. Reduction of ferric chloride catalyst in the Friedel-Crafts reaction has been previously observed. 6 The ferrous chloride-activated carbon catalyst was tested at 300°( expt.30) and at 400°( expt. 31). Toluene was not produced at either temperature. Hydrogen chloride was absent in the exit gas from the 300°e xperiment, but it was present in the 400°e xperiment.The "solid" phosphoric acid catalyst showed no activity at approximately ten seconds contact time at 300, 350, 400 and 450°. Aluminum chloride adsorbed on activated carbon was active as would be expected, but three consecutive eight-hour periods (expts. 36-A, 36-B, 36-C) at 150°showed that the activity dropped off rapidly. The higher temperatures used with the other catalysts could not be employed with the -aluminum chloride-activated carbon catalyst because of the sublimation of aluminum chloride.

New H‐Bonded Complexes and Their Supramolecular Liquid‐Crystalline Organizations

“…The carboxylic acids used in this research were prepared according to synthetic methods from the literature. [5,16,17] Experimental details are reported in the Supporting Information. The thermal properties of all these compounds are gathered in Table 1.…”

2,4,6‐Trimethylpyridine‐Derived Vinylene‐Linked Covalent Organic Frameworks for Confined Catalytic Esterification

“…Various styrylpyridines have been synthesized by the condensation of methyl pyridines and aldehydes in moderate yields by using acetic anhydride as an acylating reagent. [15] In order to reach a deeper understanding of this type of reaction and achieve optimized reaction conditions, we systematically investigated the role of several common acylating reagents, such as acyl halides, acid, and anhydrides, in promoting Knoevenagel condensation at the methylsubstituted nitrogen-containing aromatics. Initially, we took TMP as an example for conducting Knoevenagel condensation with benzaldehyde (BA) to prepare the model molecule 2,4,6-tri(E)-styrylpyridine (TSP).…”

Cocrystals of 1,3,5-Cyclohexanetricarboxylic Acid with 4,4‘-Bipyridine Homologues: Acid···Pyridine Hydrogen Bonding in Neutral and Ionic Complexes

“…cis , cis -1,3,5-Cyclohexanetricarboxylic acid (H 3 CTA) was purchased from Aldrich (mp 216−217 °C). 1,2-bis(4-pyridyl)ethane (bipy-eta, mp 110−112 °C), 1,4-bis(4-pyridyl-2-ethyl)benzene (bipy-etabz, mp 118−120 °C), 1,2-bis(4-pyridyl)ethylene (bipy-ete, mp 150−153 °C), and 1,4-bis(2-(4-pyridyl)ethenyl)benzene (bipy-etebz, mp 265−267 °C) were synthesized according to literature procedures . Molecular complexes were crystallized as follows.…”