The chemistry of acetylenic ethers XV: The reaction of ethoxyacetylene with aqueous solutions of tertiary aliphatic amines

Abstract

Ethoxyacetylene I reacts with tertiary aliphatic amines and water to yield (a-ethoxyvinyl) -trialkylammonium hydroxides 11. Several crystalline salts of these bases were obtained. Catalytic hydrogenation of (a-ethoxyvinyl) -trimethylammonium iodide IIa yielded trimethylammonium iodide and diethyl ether.Reppel) found that by the reaction of acetylene with trimethylamine and water vinyl-trimethylammonium hydroxide was formed.W e observed that an analogous reaction can be performed with ethoxyacetylene. When this compound was shaken with a solution of trimethylamine in water, heat was evolved, and after some time a strongly alkaline solution resulted. W e could obtain several stable and crystalline salts from the base. The iodide, picrate, and perchlorate were not hygroscopic, whereas the chloride, bromide, and sulphate were deliquescent.The analysis of the salts indicated that the base had the com-

Synthesis, Characterization, and Computational Modeling of N-(1-Ethoxyvinyl)pyridinium Triflates, an Unusual Class of Pyridinium Salts

“…Limited attempts to utilize these potentially valuable compounds in [4 + 2]-cycloadditions were unsuccessful, however, and no follow-up studies on the structure and reactivity of these interesting species are available. While numerous studies have been published on the synthesis and reactivity of neutral ketene N , O -acetals [ 39 ] like 8 and 9 , only scattered reports exist of N -quaternized ketene N , O -acetals ( N -(1-alkoxyvinyl)ammonium salts) [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ], such as compounds 10 and 11 . Furthermore, general methods of synthesis and systematic evaluation of reactivity within this potentially valuable compound class are lacking.…”

Synthetic approach for unsaturated precursors for parahydrogen induced polarization of choline and its analogs

“…Both ethoxy‐ and benzoxy‐acetylenes shown in approach #2, Figure , have been prepared previously by relatively straightforward methodologies. Ethoxyacetylene has been shown to react with trimethylamine, albeit with reverse regioselectivity, yielding (α‐ethoxyvinyl)trialkylammonium hydroxides unsuitable for 15 N‐choline PHIP.…”

Synthesis and crystal structure of a bench-stable pyridinium ketene hemiaminal: 1-(1-ethoxyethenyl)-2-[methyl(phenyl)amino]pyridin-1-ium trifluoromethanesulfonate

“…N-Quaternized ketene N,O-acetals are a generally unstable class of compounds, most often invoked as reactive intermediates (Kantlehner, 2006). Consequently, there are very few reports of isolable and well-characterized compounds in this class despite their first appearance in the literature over eight decades ago (Arens et al, 1955;Barnes et al, 1940;Filippova et al, 1983;Herkes & Simmons, 1973;Klages & Drerup, 1941;Lehn & Seher, 1966;Otsuru et al, 1969). In 2018, our laboratory discovered that several pyridinium ketene hemiaminals were unusually stable analogues of the N-quaternized ketene N,O-acetal class, amenable to isolation and purification by chromatography or recrystallization (Fig.…”

“…After one minute of stirring at room temperature, the sealed microwave vial was placed in a pre-heated 313 K oil bath and stirred for 24 h. The reaction mixture was cooled to room temperature then concentrated to a residue that was purified by silica gel column chromatography using a 0-70% gradient of isopropanol in chloroform to provide compound IV as a yellow solid (190 mg, 94%). 1 H NMR (500 MHz, Acetone-d 6 ) 8.36-8.26 (m, 2H), 7.69 (d, J = 9.1 Hz, 1H), 7.52 (t, J = 7.7 Hz, 2H), 7.45-7.38 (m, 4H), 4.69 (d, J = 4.8 Hz, 1H), 4.36 (d, J = 4.8 Hz, 1H), 3.74 (s, 3H), 3.63 (q, J = 7.1 Hz, 2H), 1.27 (t, J = 7.0 Hz, 3H); 13 C NMR (125 MHz, CDCl 3 ) 154. 5, 152.6, 145.5, 144.2, 142.6, 129.8, 127.9, 126.4, 121.5 (q, 1 J CF = 320 Hz, CF 3 ), 119.5, 116.4, 85.9, 65.8, 43.4, 13.2 et al, 2020); software used to prepare material for publication: publCIF v1.9.21_c (Westrip, 2010).…”