Study of Synthesis of 2‐(2‐Alkoxyphenyl)‐1H‐imidazoles. Comparison of Oxidative Aromatization Reactions of Imidazolines.

Abstract

SUMMARYThe reaction of methyl salicylate with ethane-1,2-diamine has been used to prepare 2-(2-hydroxyphenyl)-1H-imidazoline. This compound was alkylated with alkyl halides to give five new 2-(2-alkoxyphenyl)-1H-imidazolines (alkyl = propyl, isopropyl, isobutyl, sec-butyl, benzyl). Seven types of transformation reactions of imidazolines into the respective imidazoles were tested. Out of them successful were the dehydrogenation on palladium in toluene (several-day refluxing), oxidation with activated manganese dioxide in toluene (several-hour heating at 60 °C), and the oxidation with potassium nitrosodisulfonate (Fremy's salt) at room temperature. Seven new 2-(2-alkoxyphenyl)-1H-imidazoles were synthesized (alkyl = ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, benzyl) via mentioned methods.Comparison of individual oxidative aromatization reactions is discussed from the point of view of experimental arrangement, reaction time and conditions, purity of the products obtained, and yields.

Fragmentation of Trifluoromethylated Alkenes and Acetylenes by N,N-Binucleophiles. Synthesis of Imidazolines or Imidazolidines (Oxazolidines) Controlled by Substituent

“…The β-bromo-, β-chloro-, and β-fluoro-β-(tri- or difluoromethyl)styrenes 1a − u were prepared as reported previously. NMR spectra of compounds 7a,b,d,g , 7c , 7f , 7h , 8a,b , 17 , 22b , and 25 are in agreement with published data.…”

“…Yield 45%; white solid; mp 60−62 °C (lit . 60−64 °C); 1 H NMR (400 MHz, CDCl 3 ) δ 3.64 (s, 4H, 2CH 2 ), 3.89 (s, 3H, MeO), 5.70 (br s, 1H, NH), 7.00 (t, J = 7.8 Hz, 1H, Ar), 7.06 (d, J = 7.8 Hz, 1H, Ar), 7.43 (td, J = 7.8 Hz, J = 1.8 Hz, 1H, Ar), 8.01 (dd, J = 7.8 Hz, J = 1.8 Hz, 1H, Ar).…”

Comparing the Catalytic Activity of Silica-Supported Vanadium Oxides and the Polymer Nanofiber-Supported Oxidovanadium(IV) Complex toward Oxidation of Refractory Organosulfur Compounds in Hydrotreated Diesel

“…In the FT-IR spectrum of the copolymer (Figure 2b), the band at 1494 cm −1 can be attributed to the azomethine stretch [ν(C N)]. 28 Coordination of oxidovanadium(IV) to the metal center results in a shift of the azomethine band to 1530 cm −1 . 29 The band at 1263 cm −1 was tentatively assigned to the phenolic ν(C−O) stretches in the copolymer, and the peak shifted to 1273 cm −1 upon coordination.…”

Antiprotozoal Selectivity of Diimidazoline N-Phenylbenzamides

“…As shown in Scheme 2, carboxyphthalimide 31 11 was amidated to form 4-cyanoanilide 32, deprotected with hydrazine to form 33, and then transformed 10 into amino imidazoline 9 as described above. Diimidazole 12 was obtained by high-temperature Pd-catalyzed dehydrogenation 12 As shown in Scheme 3, thiazoline 13 and oxazoline 14 were obtained in low to moderate yields from the common dintrile precursor 34 by reaction with cysteamine hydrochloride or 2amino-2-methyl-1-propanol with a ZnCl 2 catalyst 13 in hot DMA. Diimidazolines 15 and 16 and tetrahydropyridines 17 and 18 were obtained from a mixture of 34 and the corresponding diamines with sodium hydrosulfide 10 in hot DMA in 37−60% yields.…”