Solvent ether route

Illicit cocaine is extracted from coca leaf in three stages. This is usually done in three different laboratories that can be hundreds of miles apart, by a solvent-extraction route. In the final step at a crystal lab , the cocaine molecules are dissolved in an organic solvent such as ether (ethoxyethane) and insoluble impurities are filtered off. To this filtrate is added a mixture of concentrated HCl and propanone, then cocaine hydrochloride crystallizes out. Other solvents like butanone are also used. 

Reaction The alkylation of carbanions plays a very important role in organic synthesis because products used as key blocks for numerous medicine and organic syntheses are obtained. Phase transfer catalysis has been proven to be the most efficient way of carrying out this type of reaction. Compared to traditional synthetic routes, it has a number of advantages it requires neither expensive bases (sodium amide, metal hydrides, etc.) nor hazardous solvents (ether, benzene, dimethyl sulfoxide, etc.), ensuring at the same time high selectivity and yields. 

Sir Joseph Swan, as a result of his quest for carbon fiber for lamp filaments (2), learned how to denitrate nitrocellulose using ammonium sulfide. In 1885 he exhibited the first textiles made from this new artificial sHk, but with carbon fiber being his main theme he failed to foUow up on the textile possibihties. Meanwhile Count Hilaire de Chardoimet (3) was researching the nitrocellulose route and had perfected his first fibers and textiles in time for the Paris Exhibition in 1889. There he got the necessary financial backing for the first Chardoimet silk factory in Besancon in 1890. His process involved treating mulberry leaves with nitric and sulfuric acids to form cellulose nitrate which could be dissolved in ether and alcohol. This collodion solution could be extmded through holes in a spinneret into warm air where solvent evaporation led to the formation of soHd cellulose nitrate filaments. 

A method for the polymerization of polysulfones in nondipolar aprotic solvents has been developed and reported (9,10). The method reUes on phase-transfer catalysis. Polysulfone is made in chlorobenzene as solvent with (2.2.2)cryptand as catalyst (9). Less reactive crown ethers require dichlorobenzene as solvent (10). High molecular weight polyphenylsulfone can also be made by this route in dichlorobenzene however, only low molecular weight PES is achievable by this method. Cross-linked polystyrene-bound (2.2.2)cryptand is found to be effective in these polymerizations which allow simple recovery and reuse of the catalyst. 

The Grignard method was the first route used commercially in the production of silicone intermediates. Its great advantage is its extreme flexibility since a wide range of organic groups may be attached to the silicon in this method. Because of the need to use ether or other inflammable solvents considerable production hazards arise. On economic grounds the main drawbacks of the process are the multiplicity of steps and the dependence on silicon tetrachloride, which contains only 16% Si and is thus a rather inefficient source of this element. 

The advantage of the activated displacement polymerization is the facile incorporation of different and unconventional structural units in the polymer backbone. Most of the heteroarylene activated polyethers prepared by this route are soluble in many organic solvents. The solubility behavior of new polyethers is shown in Table 8. In contrast to many polyphenylenequi-noxalines, poly(aryl ether phenylquinoxalines) prepared by the quionoxaline activated displacement reaction are soluble in NMP. Solubility in NMP is important since it is frequently used for polymer processing in the microelectronics industry [27]. 

Dimethyl carbonate (DMC) is a colorless liquid with a pleasant odor. It is soluble in most organic solvents but insoluble in water. The classical synthesis of DMC is the reaction of methanol with phosgene. Because phosgene is toxic, a non-phosgene-route may be preferred. The new route reacts methanol with urea over a tin catalyst. However, the yield is low. Using electron donor solvents such as trimethylene glycol dimethyl ether and continually distilling off the product increases the yield. ... 

The AICI3-catalyzed polycondensation of diphenyl ether with a mixture of terephthaloyl chloride and isophthaloyl chloride is a relatively inexpensive route to poly(ether ketone)s. The polymerizations were carried out in chlorinated solvents... 

Among the routes for preparing phosphinous amides, the most frequently used method is the aminolysis of halophosphanes, most usually chlorophosphanes [32-34], because a number of such halophosphanes are easily accessible from commercial sources. These reactions usually provide the target species, i.e., trisubstituted compounds 1 in Scheme 1, in high yield. The HCl liberated from the reaction forms a salt with an organic base (either excess of the starting amine or externally added as, for example TEA or DBU, sometimes in the presence of DM AP) which is insoluble in the reaction solvent, typically diethyl ether... 

As discussed, the cultivation of C. sativa with high content of A9-THC (drug-type) is not allowed in many coimtries. Because of this, there is no opportunity to harvest a high amoimt of the medicinally important substance A9-THC directly from plant material. In the synthesis route for semisynthetic A9-THC, natural CBD from fiber hemp plants is employed. It can be extracted with non-polar solvents such as petroleum ether and purified by recrystalUza-fion in n-pentane. This procedure avoids the formation of abnormal CBD and gives the opportunity to produce A9-THC from fiber hemp. Semisyn-fhetic A9-THC is disfinguishable from the synthetic compound because it contains, besides the major product, small amounts of A9-THC-C3 and A9-THC-C4, which are not available in the synthetic product. 

Tosylate is displaced by weak oxyanions with little elimination in aprotic solvents, providing alternative routes to polymer-bound esters and aryl ethers. Alkoxides, unfortunately, give significant functional yields of (vinyl)polystyrene under the same conditions. Phosphines and sulfides can also be prepared from the appropriate anions (57), the latter lipophilic enough for phase-transfer catalysis free from poisonning by released tosylate. 

Tetramethyl-l,3-disilacyclobutane had been prepared earlier by Knoth and Lindsey [10], but a multistep synthesis was involved which was not generalizable to the synthesis of Si-functional 1,3-disilacyclobutanes. The reaction shown in eq. 4, provided it is carried out in the right way, represents a good, general route to 1,3-disilacyclobutanes. This reaction was reported first by Muller and his coworkers [11]. In this work, diethyl ether was used as reaction solvent and the product yield was only around 4%. Somewhat better yields were obtained" by Russian workers [12], but it was the detailed studies of the (chloromethyl)chlorosilane/ magnesium reaction by Kriner [13] which provided a good synthesis of... 

Prior to our original report7 on this method, acceptable and general preparative routes to a-iodocycloalkenones had not been described. Treatment of a p-substituted cycloalkenone with trimethylsilyl azide and a mixture of iodine and pyridine sequentially in dichloromethane has now been reported as a method for the preparation of p-substituted-a-iodocycloalkenones.8 The combination of iodine and pyridinium dichromate has also been reported to provide a-iodoenones from enones as well as from ethynyl carbinols.9 10 Some successes have also been achieved with enones and iodine azide (IN3)11 and iodine/ceric ammonium nitrate.12-14 The submitters first variant5 of the present procedure used carbon tetrachloride as a solvent. In this procedure this solvent has been replaced with the more benign diethyl ether. 

During the hydrogenolysis of primary haloalkanes, diborane is produced and it provides a viable route for its preparation in non-ethereal solvents (see Section 11.5) [5]. 

A synthetic application of the sonolysis of iron carbonyls is the preparation of useful ferrilactones. The alkenyl epoxides (2, R = H, Ph, 1-hexanyl) are smoothly converted to the corresponding ferrilactone complexes (3) on reaction with Fe2(CO)9 suspended in THF and sonicated at room temperature [53]. Such complexes undergo several synthetically useful transformations (Scheme 3.7) including oxidation with Ce(IV) as a route to P-lactone natural products or P-lactam antibiotics and reaction with CO to afford 5-lactones [54]. Somewhat surprisingly this reaction is efficient even in diethyl ether, a volatile solvent which delivers low cavitation energy. 

Column III shows the effect of ultrasound upon the product ratio with methanol as solvent. As can be seen there is now 53 % bibenzyl, 32 % of methyl ether and 6% of methyl ester (with a total of 5 % of other products) suggesting a slight shift towards the two-electron products, but with an overall diminuition of solvent discharge (approx. 6% ester) and side-reactions (approx. 6%). This result confirms the fact the phenyl acetate electrooxidation favours the one-electron route (to bibenzyl) in a wide range of conditions [61], and is much less sensitive to mechanistic switches by manipulation of parameters (e. g. ultrasound) than is cyclohexane carboxylate electrooxidation [54]. 

The Grignard route to diorganyl ditellurides suffers from lack of generality and the mechanism of the oxidation seems to be uncertain. Alkylmagnesium halides demonstrate lack of reactivity towards elemental tellurium/ whereas aryhnagnesium halides in ether as the solvent furnish a mixture of ditellurides and tellurides. Satisfactory results are obtained by tellurium insertion in aryhnagnesium halides in THF followed by oxidation before or after aqueous work-up. ... 

The Ponzio reaction provides a useful route to gem-dinitro compounds and involves treating oximes with a solution of nitrogen dioxide or its dimer in diethyl ether or a chlorinated solvent. The Ponzio reaction works best for aromatic oximes where the synthesis of many substituted aryldinitromethanes have been reported. Compound (56), an isomer of TNT, is formed from the reaction of dinitrogen tetroxide with the oxime of benzaldehyde (55) followed by mononitration of the aromatic ring with mixed acid. Yields are usually much lower for aliphatic aldoximes and ketoximes. " The parent carbonyl compound of the oxime is usually the major by-product in these reactions. 

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