Hydroxypropyl ether

Zeolites have also been successfully applied in the reverse reaction, i.e. the hydrolysis of ethers to alcohols. A relevant example is the splitting of bis(3-hydroxypropyl)ether. This compound is a by-product in 1,3-propanediol synthesis, which can be performed by hydration of acrolein and reduction of 3-hydroxypropanal (23). In the hydrolysis of bis(3-hydroxypropyl)ether, a 20 weight % aqueous solution of the ether is passed over a ZSM-5 catalyst at 240°C ... 

Alcohols react easily with trimethylene ozide in the presence of catalytic amounts (if sulfuric or 7> tolueiiD sulfonic adds to fom the 3-hydroxypropyl ethers.(In addition, some low molecular polymeric... 

Hydroxypropyl ethers. With T.MS ductive ring opening very cleanly. Both C-completely under the same conditions. 

Benzylhemi formal AMPS 2401 Monomer Resordnol di (3-hydroxypropyl) ether Hydrad C... 

PTT acts in a similar manner to PET, forming bis-3-hydroxypropyl ether groups in the polymer chain, and volatile by-prodncts. The volatile product in this case is allyl alcohol, and the more problematical acrolein [36]. 

Etherification. Carbohydrates are involved in ether formation, both intramoleculady and intermoleculady (1,13). The cycHc ether, 1,4-sorbitan, an 1,4-anhydroalditol, has already been mentioned. 3,6-Anhydro-a-D-galactopyranosyl units are principal monomer units of the carrageenans. Methyl, ethyl, carboxymethyl, hydroxyethyl, and hydroxypropyl ethers of cellulose (qv) are all commercial materials. The principal starch ethers are the hydroxyethyl and hydroxypropylethers (see Cellulose ethers Starch). 

Pigment retention and drainage additives made with polyamines include polyamines made from ethyleneamines, ethan olamines, and epichl orohydrin (262) ethyleneamines combined with phosphoms-modifted polyamines made by reaction of ethyleneamines with POCl [10025-87-3] (263) and a DETA—glutaric acid polyamide crosslinked with PEG-bis(3-chloro-2-hydroxypropyl) ether (264). Polyamines made from ethyleneamines and EDC are useful flocculating agents (265). 

Therapeutic Function Topical protectant ophthalmic vehicle Chemicel Name Callulose 2-hydroxypropyl ether Common Name Hyprolose Structural Formula ... 

Although it is a simple matter to attach a single hydroxypropyl residue to a phenolic hydroxyl, the controlled synthesis of chain-extended hydroxypropyl ethers is much more difficult (Fig. 2) (5). The difficulty is that of selectively alkylating an aliphatic hydroxyl on the substrate in the presence of aliphatic hydroxyls on hydroxypropyl groups. Thus we required a method for the preparation of compounds of the type shown in Figure 2 where n is precisely known and controlled (rather than being a statistical range of values). 

Our solution to this synthetic problem was the development of an iterative technique for preparing hydroxypropyl ethers from allyl ethers via oxymercuration-reduction. Figure 3 illustrates the process for the preparation of a series of three chain-extended hydroxypropyl derivatives of 2,6-dimethoxyphenol. Conversion of phenol 1 to the allyl ether 2 under phase-transfer conditions (6) was followed by oxymercuration (7) to give the intermediate organomercurial 3, which was reduced without isolation to give hydroxypropyl ether 4 in 64% overall yield. Ether 4. was then allylated to provide 5, which upon oxymercuration-reduction afforded hydroxypropyl derivative 6. One further iteration of the allylation-oxymercuration-reduction sequence yielded the hydroxypropyl compound 7. 

Transmetalation of the vinylmercurial derivative with n-BuLi, followed by reaction with 2-lithium thienylcyanocuprate and subsequent addition of BF3-OEt2 and 167, leads to lactone 168 in 86% yield. Cationic biscyclization of vinylsilane 168 with TiCL and Ti(Oi-Pr)4 (at a proportion of 5 1), followed by the cleavage of the remaining acetal (oxidization of the hydroxypropyl ether side chain and subsequent 15-elimination of piperidinium acetate) leads to secondary alcohol 169. 

The high resolution solid-state 13C NMR spectrum of the HMDA network observed at 80 °C leads to separate lines for the various aliphatic carbons DGEBA methyl carbons, HMDA methylene carbon in the p or y position with respect to the nitrogen atom, CH2 (of the hydroxypropyl ether) directly bonded to the nitrogen, and the CHOH - CH2 - O unit. For the aromatic... 

The ft transition clearly originates from motions of the hydroxypropyl ether sequence, but the crosslink points are also involved. Whereas the motions involved in the low-temperature part of the ft transition are quite isolated motions of HPE units, when temperature increases a cooperativity appears directly with the mobility of the crosslinks and, indirectly, with the jr-flip motions of the DGEBA phenyl rings. 

The NMR experiments clearly show a different effect of the antiplasticiser on the mobility of either the crosslink points (CH2 - N) or the hydroxypropyl ether sequence. Indeed, whereas these two groups have similar mobility in pure epoxy networks, the mobility of the crosslink points is hindered by the antiplasticiser, whereas only a slight slowing down occurs for the HPE units. Furthermore, there is no difference in mobility between the HPE sequence in the epoxy network and the one in the antiplasticiser molecule. 

The fi transition starting at 1 Hz around - 120 °C and extending to higher and higher temperatures when increasing the crosslink density, comes from motions of the hydroxypropyl ether sequence. Isolated and insensitive to crosslink density or amount of antiplasticiser in the low-temperature part of the fi transition, these motions become more and more cooperative as temperature increases. 

In the absence of pending groups or antiplasticisers, the motions of the hydroxypropyl ether units in the high-temperature part of the transition force motions of the crosslink points that are spatial neighbours of the moving HPE sequence. A crude estimate leads to an extent of cooperativity at high temperatures reaching more than six crosslink points in densely crosslinked networks. 

The reaction of sucrose with propylene oxide in aqueous basic medium affords 2-hydroxypropyl ethers.76 Similar conditions gave sucrose glycerol-sucrose hybrids by reaction with glycidol.77 Polymeric resins are obtained, starting from sucrose or partially esterified sucrose, when diepoxides are used.78,79... 

A possible way to lower the costs of fibers and films of regenerated cellulose would be to run cellulose through a twin-screw ultrasonic extruder with a minimum of solvent and pass the extrudate through a stream of hot air to recover the solvent for reuse. This stronger cellophane could be used in place of many plastic films used today. A great number of derivates of cellulose have been made. Methyl, ethyl, carboxymethyl, hydroxyethyl, and hydroxypropyl ethers are made commercially today. These are used as water-soluble polymers, except for ethylcellulose, which is a tough plastic used in screwdriver handles and such. 

Name p-Cyclodextrin, hydroxypropyl ether modified bonded phase Structure ... 

Figure 10-5 Molecular structures of BADGE and hydrolysis/ethanolysis products (1) Bisphenol A diglycidyl ether (BADGE)-, (2) Bisphenol A (2,3-dihydroxypropyl ether) diglycidyl ether (diol-epoxide) (3) Bisphenol A di-(2,3-dihydroxypropyl ether) (diol-diot) (4) Bisphenol A (3-ethoxy-2-hydroxypropyl ether) diglycidyl ether (ether-epoxide)-, (5) Bisphenol A (3-ethoxy-2-hydroxypropyl ether) (2,3-dihydroxypropyl ether) (ether-diol).

HYDROXYPROPYLAMINE see PMM250 (3-HYDROXYPROPYL)BENZENE see HHP050 p-HYDROXYPROPYL BENZOATE see HNU500 HYDROXYPROPYL CELLULOSE see HNVOOO HYDROXYPROPYL ETHER of CELLULOSE see HNVOOO... 

S)-hydroxypropyl ether (R,S)-hydroxypropyl ether (S)-naphthylethyl carbamate (R)-naphthylethyl carbamate 3,5-dimethylphenyl carbamate pnrfl-toluoyl ester acetylate acetylate... 

Guar gum is derivatized to modify its properties and functionalities. Available derivatives include the hydroxypropyl ether, the carboxymethyl ether, a cationic ether, a mixed hydrox-ypropyl cationic ether, the phosphate ester, and a mixed phosphate ester and cationic ether... 

Cellulose, hydroxypropyl ether E463 hyprolose Klucel Methoceh, Nisso HPC oxypropylated cellulose. 

The PhEur 2005 and USPNF 23 describe hydroxypropyl cellulose as a partially substituted poly(hydroxypropyl) ether of cellulose. It may contain not more than 0.6% of silica or another suitable anticaking agent. Hydroxypropyl cellulose is commercially available in a number of different grades that have various solution viscosities. Molecular weight has a range of 50 000-1 250 000 see also Section 10. 

The USPNF 23 describes low-substituted hydroxypropyl cellulose as a low-substituted hydroxypropyl ether of cellulose. When dried at 105°C for 1 hour, it contains not less than 5.0% and not more than 16.0% of hydroxypropoxy groups (—OCH2CHOHCH3). Low-substituted hydroxypropyl cellulose is commercially available in a number of different grades that have different particle sizes and substitution levels. 

Hydroxypropyl starch is a derivative of natural starch it is described in the JPE 2004 as a hydroxypropyl ether of corn starch. 

A purified form of cellulose, obtained from cotton linters or wood pulp, is reacted with sodium hydroxide solution to produce a swollen alkali cellulose that is chemically more reactive than untreated cellulose. The alkali cellulose is then treated with chloromethane and propylene oxide to produce methyl hydroxypropyl ethers of cellulose. The fibrous reaction product is then purified and ground to a fine, uniform powder or granules. 

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