Triethylene glycol dichloride

The second general approach outlined by Pedersen is the so-called method W in which the two hydroxyl groups are separated by a portion of the crown chain. A good example of this is the assembly of 18-crown-6 from triethylene glycol and triethylene glycol dichloride. 

It is interesting to note that Kulstad and Malmsten have utilized yet another method for introducing nitrogen into the crown precursors. They utilize sodium azide in DMSO to displace halogen from triethylene glycol dichloride. The bis-azide is then reduced using hydrogen sulfide in ethanol. ... 

Fuel processing to recover plutonium was an important activity from the earliest days of the atomic energy program. A small pilot plant was built at CRNL in parallel with the construction of NRX. It operated from 1949 to 1953 to extract plutonium from dissolved fuel with triethylene glycol dichloride in a batch process. Ammonium nitrate was the salting-out agent (75). Subsequently, the waste solution from this operation was treated with tributylphosphate (TBP) to remove uranium and residual plutonium, and the ammonium nitrate decomposed before the waste was stored as a concentrated fission product solution. 

Crown ethers complex cations, as discussed later in this article. Conversely, cations can organize the reactive partners to form the macrocyclic products. In the absence of some organizing principle, the formation of large rings is an improbable process. The reaction of triethylene glycol with triethylene glycol dichloride in the presence of KOH. for example, begins with ether formation ... 

The second concept inherent in the template effect is that cations of different sizes favor the formation of different ring sizes. In the cyclooligomerization of ethylene oxide reported by Dale et al. relatively more 15-crown-5 was formed in the presence of Na and more 18-crown-6 was formed when was added to the reaction mixture. When the reacting components are triethylene glycol and triethylene glycol dichloride, the possibilities are the formation of rings having sizes of 9. 

Scheme III shows a convenient three step synthesis of the allyloxymethyl-substituted diazacrowns 3 and 5 [15]. The diazapentaethylene glycols 11 and 12 were prepared in good yields from triethylene glycol dichloride and iV-benzyl- or AT-ethylethanolamine [20]. The reaction of 11 or 12 with the allyloxymethyl-substituted epoxide gave a good yield of the allyloxymethyl-substituted diazahex-aethylene glycol 13 or 14. Compound 14 was purified by distillation. The Okahara ring closure reactions of 13 and 14 with tosyl chloride [21] gave excellent yields of 3 and 5, respectively. The overall yields for this process was 34% for 3 and 35% for 5 [15].

Lockhart and coworkers incorporated nitrogen into a crown ether through the reaction of ortto-aminophenol with triethylene glycol dichloride and obtained two products, azabenzo-15-crown-5 and yV-(2-phenol)aza-12-crown-4. The latter was an early example of a lariat ether, discussed below. 

The crown ether called 18-crown-6 is prepared by reaction of triethylene glycol with triethylene glycol dichloride in the presence of base [46] or by the cyclo-oligomerization of ethylene oxide [51]. Purification is effected by distillation and crystallization. The sequence is shown in equation 1.19. 

The commonly used 2.2.2-cryptate is prepared by condensing triethylene glycol dichloride with tosylamide [49]. This affords the doubly N-protected macrocyclic aminoether 4. Detosylation yields the compound containing secondary nitrogen atoms (5). Double amide formation at high dilution affords the bicyclic structure 6 which can be reduced to the desired cryptate, 7. The sequence is formulated in equations 1.20-1.22. 

Methylphenol is converted to 6-/ f2 -butyl-2-methylphenol [2219-82-1] by alkylation with isobutylene under aluminum catalysis. A number of phenoHc anti-oxidants used to stabilize mbber and plastics against thermal oxidative degradation are based on this compound. The condensation of 6-/ f2 -butyl-2-methylphenol with formaldehyde yields 4,4 -methylenebis(2-methyl-6-/ f2 butylphenol) [96-65-17, reaction with sulfur dichloride yields 4,4 -thiobis(2-methyl-6-/ f2 butylphenol) [96-66-2] and reaction with methyl acrylate under base catalysis yields the corresponding hydrocinnamate. Transesterification of the hydrocinnamate with triethylene glycol yields triethylene glycol-bis[3-(3-/ f2 -butyl-5-methyl-4-hydroxyphenyl)propionate] [36443-68-2] (39). 2-Methylphenol is also a component of cresyHc acids, blends of phenol, cresols, and xylenols. CresyHc acids are used as solvents in a number of coating appHcations (see Table 3). 

In 1976, Johns, Ransom and Reese reported improvements in the previously reported syntheses of 18-crown-6 and 15-crown-5. By using tetraethylene glycol rather than triethylene glycol and the correspondingly shorter dichloride (2.5 equivalents of the latter) in concert with KOH (no water added), they were able to realize a 6% yield improvement in the synthesis of 18-crown-6 over the previously published method . The improvement in the yield of 15-crown-5 was of somewhat greater interest, being 38% compared to Liotta s previous report of 15% . ... 

Saccharine can be used to convert an alkyl halide into a primary amine. Saccharine is reacted with the alkyl halide followed by a mild acidic cleavage of the resulting benzenesulfonylcarboxy residue (Abe, 1955 Eckenroth and Koerppen, 1896, 1897). This reaction has been used in cyclizations by first treating the dichloride derivative of a di- or triethylene glycol with the sodium salt of saccharine in DMF in the presence of sodium iodide to form the bis-... 

Di- or triethylene glycol can be converted readily into the corresponding dichloride or ditosylate. Reaction of a diol with either the dihalide or the ditosylate under basic conditions can lead to crowns by the general reaction shown in Scheme 1. It should be noted that reaction of a diol HO—R—OH with CICH2CH2OCH2CH2CI in the presence of two equivalents of a suitable base can lead to more than one product. The stoichiometry for formation of the 1 1, 2 2, 3 3, etc. products is identical. Selective formation of a particular product will depend on the identity, size, and chemical properties of R and any templating ion present in the reaction mixture. 

Penta- and heptaethylene glycols were prepared by condensation of the monosodium salts of mono- and diethylene glycols, respectively, with the dichlorides of the triethylene glycol [4]. 

Pure, discrete diethylene, triethylene and tetraethylene glycols are all commercially available from a variety of sources. Pentaethylene glycol and longer polyoxyethylene glycols are generally prepared by condensation of two equivalents of a shorter glycol with a diol dichloride or ditosylate. Such methods have been reported by Pedersen", Cornforth , and Krespan . The approach is illustrated in Eq. (7.1), below. 

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