Bis 2-ethoxyethyl

Technetium-99m tetrafosmin ( Tc-(V)02 (l,2-bis(bis(2-ethoxyethyl)phosphino)ethane) (see Fig. 3d)) is a myocardial perfusion agent. It is used as an adjunct in the diagnosis and localization of myocardial ischemia and/or infarction. 

The synthetic preparation of 2,8-dichlorodibenzo-p-dioxin was facilitated in that the chemical precursor, 2,4,4 -trichloro-2 -hydroxydiphenyl ether, was available as a pure material. Condensation was induced by heating the potassium salt at 200 °C for 15 hours in bis (2-ethoxyethyl) ether. Product analysis by GLC and mass spectrometry revealed an unexpected dichlorophenol and a monochlorodibenzo-p-dioxin. Further, the product initially isolated by crystallization from the reaction mixture was 2,7-dichlorodibenzo-p-dioxin, rather than the expected 2,8-isomer. Cooling of the mother liquor yielded crystalline plates which were shown to be 2,8-dichlorodibenzo-p-dioxin by x-ray diffraction (Reaction 2). 

The preparation of 2,3,7,8-tetrachlorodibenzo-p-dioxin by chlorination of 2,7-dichlorodibenzo-p-dioxin yields a product containing significant quantities of trichloro- and pentachlorodibenzo-p-dioxins (11). Such mixtures are not amenable to separation on a preparative scale. Although 2,3,7,8-tetrachlorodibenzo-p-dioxin has been prepared by the pyrolytic condensation of sodium 2,4,5-trichlorophenate, this method is undesirable for preparation of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the gram scale (2, 12). The pyrolytic reaction is difficult to control and the potential danger is enhanced by the product s toxicity. The salt was dissolved in bEEE [bis(2-ethoxyethyl) ether, bp 189°-190°C] and refluxed for 15 hours with the Ullmann catalyst. The desired product was obtained in 39% yield by condensation of potassium 2,4,5-trichlorophenate (Reaction 3). 

Since the first report in 1960 of the observation that sodium methoxide induced carbenoid decomposition of cyclobutanone tosylhydrazone (1) at 180 °C in either bis(2-ethoxyethyl) ether or /V-methylpyrrolidone results in an intriguing ring contraction to produce methylenecyclopropane (3),1 many experimental results have been presented invoking cyclobutylidene (2) as a key intermediate in this rearrangement. 

Bis-(2-ethoxyethyl) ether see diethylene glycol diethyl ether. 

Allyloxy-2,3-epoxypropane, 2428 t Bis(2-ethoxyethyl) ether, 3071 Bis-(2-methoxyethyl) ether, 2544 t 1,3-Butadiene, 1476 t 1,3-Butadiyne, 1381 t 2-Butanol, 1689 t Buten-3-yne, 1419 t Butyl ethyl ether, 2535 t Butyl vinyl ether, 2478 t 2-Chloro-1,3-butadiene, 1447 t 2-Chloroethyl vinyl ether, 1552 t Chloroethylene, 0726 Cinnamaldehyde, 3128 t Crotonaldehyde, 1513... 

Bis(2-butoxyethyl) phthalate Bis(2-ethoxyethyl) phthalate Bis(2-ethoxyethyl) 175 I MeOH... 

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