1-Chloro diethyl ether

The use of ethers as cocatalysts for the cationic polymerisation of alkenyl monomers induced by Lewis acids has received little systematic attention and the mechanism through which these compounds operate is not well understood. The complex diethyl-ether-boron fluoride has been extensively used as a very convenient cationic initiator, but mostly for preparative purposes. As in the case of alcohols and water, ethers are known to act as inhibitors or retarders in the cationic polymerisation of olefins, if used obove cocatalytic levels, because they are more nucleophilic than most rr-donor monomers. Imoto and Aoki showed that diethyl ether, tetrahydrofuran, -chloro-diethyl ether and diethyl thioether are inhibitors for the polymerisation of styrene-by the complex BF3 EtjO in benzene at 30 °C, at a concentration lower than that of the catalyst, but high enough (0.5 x 10 M) to quench the active species formation for a time. Their action was temporary in that the quenching reaction consumed them, and therefore induction periods were observed, but the DP s of the polystyrenes were independent of the presence of such compounds, as expected from a classical temporary inhibition. 

A mixture of 0.10 mol of freshly distilled 3-methyl-3-chloro-l-butyne (see Chapter VIII-3, Exp. 5) and 170 ml of dry diethyl ether was cooled to -100°C and 0.10 mol of butyllithium in about 70 ml of hexane was added at this temperature in 10 min. Five minutes later 0.10 mol of dimethyl disulfide was introduced within 1 min with cooling betv/een -100 and -90°C. The cooling bath vjas subsequently removed and the temperature was allowed to rise. Above -25°C the clear light--brown solution became turbid and later a white precipitate was formed. When the temperature had reached lO C, the reaction mixture was hydrolyzed by addition of 200 ml of water. The organic layer and one ethereal extract were dried over potassium carbonate and subsequently concentrated in a water-pump vacuum (bath... 

A suspension of sodium amide in 500 ml of anhydrous liquid artmonia was prepared from 18 g of sodium (see Chapter II, Exp. 11). To the suspension was added in 10 min with swirling a mixture of 0.30 mol of 1-chloro-l-ethynylcyclohexane (see VIII-2, Exp. 27) and 50 ml of diethyl ether. The reaction was very vigorous and a thick suspension was formed. The greater part of the ammonia was evaporated by placing the flask in a water bath at 50°C. After addition of 500 ml of ice-water the product was extracted three times with diethyl ether. The ethereal extracts were dried over anhydrous KjCOj and subsequently concentrated in a water-pum vacuum. Distillation of the residue afforded the amine, b.p. 54°C/15 mmHg, n 1.4345, in 87% yield. 

Isoprene reacts with a-chloroalkyl ethers in the presence of ZnCl in diethyl ether from 0—10°C. For example,a-chloromethyl methyl ether at 10°C gives a 6 1 ratio of the 1,4-adduct, (F)4-chloro-l-methoxy-2-methyl-2-butene, to the 1,2-adduct, 2-chloro-l-methoxy-2-methyl-3-butene. Other a-chloroalkyl ethers react in a similar manner to give predominately the 1,4-addition product. A wide variety of aHyUc chlorides and bromides and a-chloroethers and esters add primarily 1,4- to isoprene in the presence of acid catalysts (8). 

Additives used include plasticisers such as diphenyl diethyl ether, ultraviolet light absorbers such as 5-chloro-2-hydroxybenzophenone (1-2% on the polymer) and stabilisers such as phenoxy propylene oxide. 

The first step involves the preparation of 1 -(3-isobutoxy-2-chloro)propyl pyrrolidine as an intermediate. 345 ml of thionyl chloride dissolved in 345 ml of chloroform are added, drop by drop, to 275 g of 1 -(3-isobutoxy-2-hydroxy)propyl pyrrolidine dissolved in 350 ml of chloroform, while maintaining the temperature at approximately 45°C. The reaction mixture is heated to reflux until gas is no longer evolved. The chloroform and the excess of thionyl chloride are removed under reduced pressure. The residue is poured on to 400 g of crushed ice. The reaction mixture is rendered alkaline with soda and the resulting mixture is extracted twice with 250 ml of diethyl ether. The combined ethereal extracts are dried over anhydrous sodium sulfate. After evaporation of the solvent the residue is distilled under reduced pressure. 220 g of product are obtained having the following properties boiling point = 96°C/3 mm, n074 = 1.4575. 

To the mixture of 85.5 g ethyl a-(3chloro-4.aminophenyl)-propionate hydrochloride, 142 g sodium carbonate and 600 ml dimethyl formamide, 107 g 1,4room temperature. The mixture is filtered, the filtrate evaporated in vacuo, the residue is triturated with hexane, the mixture filtered, the residue washed with petroleum ether and the filtrate evaporated. The residue is combined with 280 ml 25% aqueous sodium hydroxide and the mixture refluxed for 8 hours. After cooling, it is diluted with water, washed with diethyl ether, the pH adjusted to 5 to 5.2 with hydrochloric acid and extracted with diethyl ether. The extract is dried, filtered, evaporated and the residue crystallized from benzene-hexane, to yield the a-(3-chloro-4-pyrrolinophenyl)-propionic acid melting at 94°C to 96°C. 

Evidence for the formation of didehydroazepine 25 by an elimination-addition process has been obtained by treating Ar,Ar-diethyl-5-fluoro-3//-azepin-2-amine (24, X = F) with tm-butyl-lithium in diethyl ether at — 20 C and quenching the mixture with methanol, whereupon a 2.5-3 1 mixture of the 4-tert-butyl- 26 and the 5-tert-butyl-3//-azepine 27 is obtained in 80-90% yield.206 5-Chloro-V,A-diethyl-3//-azepin-2-amine furnishes the same products in a similar ratio. 

To a —78 C solution of 23.1 mL (100 mmol) of triisopropyl borate and 8.15 mL (110 mmol) of 3-chloro-l-propene in 100 inL of dry THF is added dropwisc via a cannula over 0.5 h a solution of LDA (110 mmol prepared in 200 mL of THF from 110 mmol of diisopropylamine and 47.9 mL of 2.3 M butyllithium in hexane), This mixture is stirred for an additional 0.5 h at — 78 "C then a solution of 75.9 ntL of 2.9 M anhyd hydrogen chloride in diethyl ether is added and the mixture is allowed to warm to 25 °C. The mixture is concentrated in vacuo (20 Torr) and the residue extracted with three 100-mL portions of pentane, Filtration under nitrogen followed by distillation under reduced pressure provides 18.0 g (88%) of diisopropyl l-chloro-2-propenylboronate bp 95-96 "C/25 Torr. Transesterification of this intermediate with 1.3-propanediol provides the title compound in almost quantitative yield bp 110-112°C/20Torr. 

To a —78 °C solution of (4/C5/ )-2-[(.S )-l-chloro-2-propcnyl]-4,5-dicyclohcxyl-l, 3,2-dioxaborolanc (6) (theoretically 2.0 mmol) in THF are added 0.20 mL (2.0 mmol) of benzaldehydc. The mixture is allowed to reach r.t. overnight and is then treated with 0.30 g (2.0 mmol) of triethanolamine. After stirring for 3 h, 15 mL of sat. aq NH4C1 are added. The phases are separated and the aqueous phase is extracted with three 20-mL portions of diethyl ether. The combined extracts are dried over MgS04 and concentrated. The oily residue is purified by flash chromatography (silica gel, petroleum ether/diethyl ether 6 1) yield 0.26 g (79%) >99% ee [capillary GC of the carbamates obtained with (5 )-(l-isoCyanoethyl)benzene],... 

A -( 1-Chloro- or bromoalkyl)amides are generally moisture-sensitive, unstable compounds, which are often directly used without further purification. Standard Lewis acids such as boron trifluoride-diethyl ether, aluminum(lll) chloride, zinc(II) chloride, tin(IV) chloride and titani-um(IV) chloride are used to generate the /V-acyliminium ion, although sometimes a catalyst is not necessary. 

The second stable biradicaloid, l,3-diaza-2,4-distannacyclobutane-l,3-diyl, 54, was unexpectedly obtained by the reaction of chloro(amino)stannylene dimer [Sn N(SiMe3)2 (n-Cl)]2 and AgOCN in diethyl ether (Scheme 2.41). ... 

The efficiency of the extraction depends on the coordinating ability of the solvent, and on the acidity of the aqueous solution which determines the concentration of the metal complex. Coordinating ability follows the sequence ketones > esters > alcohols > ethers. Many metals can be extracted as fluoride, chloride, bromide, iodide or thiocyanate complexes. Table 4.5 shows how the extraction of some metals as their chloro complexes into diethyl ether varies with acid concentration. By controlling... 

Table 4.5 Extraction of metal chloro complexes into diethyl ether... 

Silver tetrafluoroborate in ether or toluene has also been used for the synthesis of glycosyl fluorides. Peracetylated 2-chloro-2-deoxy-D-gluco- and -mannopyranosyl fluorides have been prepared by treatment of the corresponding chlorides with the aforementioned reagent.50,51 Products of kinetic control were obtained when diethyl ether was used as the solvent, whereas products of thermodynamic control were obtained when toluene was used instead. Peracetylated... 

The 1,5-substitution of l-chloro-2-en-4-ynes with Grignard reagents has been described by Dulcere and co-workers [41] but lacks generality with regard to the nucleophile (see Section 2.3). In contrast, the regioselective reaction of enyne acetates 47 with various lithium cuprates proceeds smoothly in diethyl ether, furnishing exclusively vinylallenes 48 with variable substituent patterns (Scheme 2.17) [42],... 

The efficient At-nitration of secondary amines has been achieved by transfer nitration with 4-chloro-5-methoxy-2-nitropyridazin-3-one, a reagent prepared from the nitration of the parent 4-chloro-5-methoxypyridazin-3-one with copper nitrate trihydrate in acetic anhydride. Reactions have been conducted in methylene chloride, ethyl acetate, acetonitrile and diethyl ether where yields of secondary nitramine are generally high. Homopiperazine is selectively nitrated to At-nitrohomopiperazine or At, At -dinitrohomopiperazine depending on the reaction stoichiometry. At-Nitration of primary amines or aromatic secondary amines is not achievable with this reagent. 

TABLE 21. Chloro-, bromo- and iodo-substituted aryUithiums Li—R by halogen/metal permutation between bromoarenes and butyllithium in diethyl ether... 

Bis (5-chloro-2-methylthien-3-yl)perf luorocyclopentene with n-butyllithium and octafluorocyclopentene in diethyl ether at — 78°C gave... 

Crawford and Raap generated A,Af -dicarboalkoxy-Af,Af -dialkoxyhydrazines (212, = alkoxyl) in good yields using AgiO in diethyl ether. Af,Af -Dicarbomethoxy-A,Af -dimethoxyhydrazine was also prepared by oxidation of the A-chloro-A-methoxy-nrethane (213, X = Cl, R = Me, R = MeO) with triethylamine in methanol . 

Excess phosphorus oxychloride is removed as well as possible with a rotary evaporator under reduced pressure. The residue Is cooled to room temperature and 300 ml of diethyl ether Is added. The mixture is poured into a separatory funnel. Hexane is added until the two phases separate cleanly and the funnel is shaken vigorously. The phases are separated and the lower layer is extracted with three 250-mL portions of ether (Note 4). The combined organic layers are washed with 300 mL of cold aqueous 10% hydrochloric acid and 200 mL of aqueous 5% sodium hydroxide (Note 5) and then concentrated carefully with a rotary evaporator to give 136-156 g (70-87%) of crude diethyl 2-chloro-2-cyclopropylethene-l, 1-dicarboxyl ate ... 

Di-p-chloro-bis(i74-l,5-cyclooctadiene)dirhodium(I) is a yellow-orange, air-stable solid. It can be used directly as obtained for preparative purposes5 or as a precursor for homogeneous catalysts.3,4 It can be recrystallized from dichloro-methane-diethyl ether to give orange prisms. The compound is soluble in dichloro-methane somewhat less soluble in acetone and insoluble in pentane and diethyl ether. Characteristic strong bands occur in the infrared spectrum at 819, 964, and 998 cm 1 (Nujol mull). The cyclooctadiene vinylic protons resonate in the 1H NMR spectrum at t 5.7 and the allylic protons at t 7.4-8.3 (deuteriochloroform solution). Other physical properties are given by Chatt.1... 

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