Butane-1,2-diol

Polymerization of AA and BB monomers is illustrated by butane-1,4-diol and adipic acid. The aabb repeat unit in the polymer has an Mq value of 200. If Eq. (5.4) is used to evaluate it gives the number of aa plus bb units therefore = 200(hj )/2. 

Diol Components. Ethylene glycol (ethane 1,2-diol) is made from ethylene by direct air oxidation to ethylene oxide and ring opening with water to give 1,2-diol (40) (see Glycols). Butane-1,4-diol is stiU made by the Reppe process acetylene reacts with formaldehyde in the presence of catalyst to give 2-butyne-l,4-diol which is hydrogenated to butanediol (see Acetylene-DERIVED chemicals). The ethynylation step depends on a special cuprous... 

The monomer is prepared from acetylene, formaldehyde and ammonia via but-2-yne-1,4-diol, butane-1,4-diol, y-butyrolactone and y-pyrrolidone (Figure 17.8). 

The production of alcohols by the catalytic hydrogenation of carboxylic acids in gas-liquid-particle operation has been described. The process may be based on fixed-bed or on slurry-bed operation. It may be used, for example, for the production of hexane-1,6-diol by the reduction of an aqueous solution of adipic acid, and for the production of a mixture of hexane-1,6-diol, pentane-1,5-diol, and butane-1,4-diol by the reduction of a reaction mixture resulting from cyclohexane oxidation (CIO). 

Lipase-catalyzed reaction is useful for polyester synthesis and IE was employed successfully as solvent. Uyama and Kobayashi demonstrated an efficient polyester synthesis lipase-catalyzed esterification of agipic acid with butan-1,4-diol proceeded smoothly in [bmim][BF4] solvent, particularly under reduced pressure conditions (Fig. 8). Further Russel " and Nara independently reported efficient examples of the lipase-catalyzed polyester synthesis in an IE solvent system. 

An equivalent amount of H2 was also formed. Tetrahydrofuran gave 2,2 -bitetra-hydrofuryl (C) with traces of butane-1,4-diol (D), 2-hydroxytetrahydrofuran (E) and unidentified oligomers... 

The use of azodicarboxylates as a route to dioxaphosphoranes continues to attract attention. In the most recent contribution, triphenylphosphine and di-iso-propyl azodicarboxylate (43) are shown to react with prcpane-1,3-diol and butane-1,4-diol in THF at 0°C under high dilution conditions to give the expected six-and seven-membered-ring phosphoranes (44 ab)36. In more concentrated solution however, cyclic oligomers are formed. Substituted and ccnformationally restricted 1,3- and 1,4-diols form the expected cyclic phosphoranes without recourse to high dilution techniques. 

Butane-1,4-diol, 20 36 Butane-based catalyst technology, 25 498-500... 

Cyclic carbonates are not commercially available and have to be synthesized prior to use. As a result, commercially available carbonates such as diethyl carbonate [55-57] or diphenyl carbonate [93] were evaluated in polycondensation reactions with diols to prepare polycarbonates since they allow a broader spectrum of polymers to be accessed. Unfortunately, polymerizations employing diethyl carbonate require the use of an excess diethyl carbonate [55]. Nevertheless, polymers with molecular weight of 40kDa were achieved within 16 h. Also, the polymerization of diphenyl carbonate with butane-1,4-diol or hexane-1,6-diol via the formation of a cyclic dimer produced polymers with molecular weights ranging from 119 to 339kDa [93]. 

On the contrary, while working in the synthesis of the alkaloid ru-brolone, Bogerand Zhu (91TL7643) have found 0-alkyl a,/3-unsaturated oximes 98 to participate as effective 4ir components of an intramolecular Diels-Alder reaction with an electron-deficient dienophile. Thus, 98 was prepared from butane-1,4-diol and heated in triisopropylbenzene to furnish 2-pyrindine derivatives 99 by virtue of in situ elimination of alcohol (Scheme 25). 

The formation of intermediate fluorosulfites also appears to be characteristic of the reactions of 1,3- and 1.4-diols however, these compounds were not isolated. The reaction of propane-1,3-diol, butane-1,3-diol and butane-1,4-diol with sulfur tetrafluoride gives, respectively, 3-fluoro-propan-l-ol, 3-fluorobutan-l-ol and 4-fluorobutan-l-ol.59... 

Tetrahydrofuran is a commonly used solvent. It is a relatively stable ether and is miscible with both water and organic solvents. It is manufactured on a large scale by dehydration of butane-1,4-diol and catalytic reduction of furan. It is also obtained by base treatment of 4-haloalkan-l-ols and by acidic treatment of alk-3-en-l-ols and alk-4-en-l-ols. 

Thermoplastic copolyester elastomers are generally block copolymers produced from short-chain aliphatic diols, aromatic diacids, and polyalkylene ether-diols. They are often called polyesterether or polyester elastomers. The most significant commercial product is the copolymer from butane-1,4-diol, dimethyl terephthalate, and polytetramethylene ether glycol [25190-06-1/, which produces a segmented block copolyesterether with the following structure. 

Hydroformylation of 2,6-dimethyl-6-hepten-2-ol produces hydroxycitronellal (equation 12).22 Subjecting allyl alcohol to hydroformylation reaction conditions with HCo(CO>4 yields only propanal, isomerization taking place more rapidly than hydroformylation.2 Phosphine-modified rhodium catalysts will convert allyl alcohol to butane-1,4-diol under mild conditions in the presence of excess phosphine, however (equation 13).5 30 31 When isomerization is blocked, hydroformylation proceeds normally (equation 14). An elegant synthesis of the Prelog-Djerassi lactone has been accomplished starting with the hydroformylation of an allylic alcohol (equation IS).32... 

When either an alcohol or an amine function is present in the alkene, the possibility for lactone or lactam formation exists. Cobalt or rhodium catalysts convert 2,2-dimethyl-3-buten-l-ol to 2,3,3-trimethyl- y-butyrolactone, with minor amounts of the 8-lactone being formed (equation 51).2 In this case, isomerization of the double bond is not possible. The reaction of allyl alcohols catalyzed by cobalt or rhodium is carried out under reaction conditions that are severe, so isomerization to propanal occurs rapidly. Running the reaction in acetonitrile provides a 60% yield of lactone, while a rhodium carbonyl catalyst in the presence of an amine gives butane-1,4-diol in 60-70% (equation 52).8 A mild method of converting allyl and homoallyl alcohols to lactones utilizes the palladium chloride/copper chloride catalyst system (Table 6).79,82 83... 

Dichlorobutane. Place 22.5 g (0.25 mol) of redistilled butane- 1,4-diol and 3 ml of dry pyridine in the flask in an ice bath. Add 119 g (73 ml, 1 mol) of redistilled thionyl chloride dropwise to the vigorously stirred mixture at such a rate that the temperature remains at 5-10 °C. When the addition is complete, remove the ice bath, keep the mixture overnight and then reflux for 3 hours. Cool, add ice-water cautiously and extract with ether. Wash the ethereal extract successively with 10 per cent sodium hydrogen carbonate solution and water, and dry with magnesium sulphate. Remove the ether by flash distillation and distil the residue under reduced pressure. Collect the 1,4-dichlorobutane at 55.5-56.5 °C/14mmHg the yield is 18 g (58%). The b.p. under atmospheric pressure is 154-155 °C. 

Dibromobutane (from butane-1,4-diol). Use 45 g (0.5 mol) of redistilled butane-1,4-diol, 6.84g (0.22mol) of purified red phosphorus and 80g (26 ml, 0.5 mol) of bromine. Heat the glycol-phosphorus mixture to 100-150 °C and add the bromine slowly continue heating at 100-150 °C for 1 hour after all the bromine has been introduced. Allow to cool, dilute with water, add 100 ml of ether and remove the excess of red phosphorus by filtration. Separate the ethereal solution of the dibromide, wash it successively with 10 per cent sodium thiosulphate solution and water, then dry over the anhydrous potassium carbonate. Remove the ether on a water bath and distil the residue under diminished pressure. Collect the 1,4-dibromobutane at 83-84 °C/ 12mmHg the yield is 73 g (67%). 

In a 500-ml three-necked flask, equipped with a thermometer, a sealed stirrer unit and a reflux condenser, place 32.5 g of phosphorus pentoxide and add 115.5 g (67.5 ml) of 85 per cent orthophosphoric acid (1). When the stirred mixture has cooled to room temperature, introduce 166g (lmol) of potassium iodide and 22.5 g (0.25 mol) of redistilled butane- 1,4-diol (b.p. 228-230°C or 133-135°C/18mmHg). Heat the mixture with stirring at 100-120 °C for 4 hours. Cool the stirred mixture to room temperature and add 75 ml of water and 125 ml of ether. Separate the ethereal layer, decolourise it by shaking with 25 ml of 10 per cent sodium thiosulphate solution, wash with 100 ml of cold saturated sodium chloride solution, and dry with magnesium sulphate. Remove the ether by flash distillation (Fig. 2.101) on a steam bath and distil the residue from a flask with fractionating side-arm under diminished pressure. Collect the 1,4-diiodobutane at 1 lO°C/6mmHg, the yield is 65 g (84%). 

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