Ethylene, preparation from methanol

The tetrahydropyranyi ether is prepared and reduced exactly as in Procedures 8a and 8c up to the point at which ethylene dibromide would be added. At this point 27 ml (61.5 g, 0.43 mole) of methyl iodide is added instead the addition requires 1-2 min and should be cautious at first. The mixture is stirred for 1 hr and the ammonia is allowed to boil off overnight. The product is isolated as described in Procedures 8a and 8c except that a larger volume of ethyl acetate is required to dissolve the product than in 8c. After removal of the ethyl acetate, the residual material is crystallized from methanol (400 ml). 

Acetylene is passed for 1 hr through a mixture consisting of 0.5 g (72 mg-atoms) of lithium in 100 ml of ethylene-diamine. A solution prepared from 1 g (3.5 mmoles) of rac-3-methoxy-18-methylestra-l,3,5(10)-trien-I7-one and 30 ml of tetrahydrofuran is then added at room temperature with stirring over a period of 30 min. After an additional 2 hr during which time acetylene is passed through the solution the mixture is neutralized with 5 g of ammonium chloride, diluted with 50 ml water, and extracted with ether. The ether extracts are washed successively with 10% sulfuric acid, saturated sodium hydrogen carbonate and water. The extract is dried over sodium sulfate and concentrated to yield a solid crystalline material, which on recrystallization from methanol affords 0.95 g (87%) of rac-3-methoxy-18-methyl-17a-ethynyl-estra-l,3,5(10)-trien-17jB-ol as colorless needles mp 161°. 

The l,l-dichloro-2,2-bis(p-methoxyphenyl)-ethylene is prepared by refluxing recrystallized methoxychlor in 95% ethyl alcohol for 2 hours with an excess of potassium hydroxide. It is recrystalfized from methanol. 

Melphalan and the racemic analog have been prepared by two general routes (Scheme I). In Approach (A) the amino acid function is protected, and the nitrogen mustard moiety is prepared by conventional methods from aromatic nitro-derivatives. Thus, the ethyl ester of N-phthaloyl-phenylalanine was nitrated and reduced catalytically to amine I. Compound I was reacted with ethylene oxide to form the corresponding bis(2-hydroxyethyl)amino derivative II, which was then treated with phosphorus oxychloride or thionyl chloride. The blocking groups were removed by acidic hydrolysis. Melphalan was precipitated by addition of sodium acetate and was recrystallized from methanol. No racemization was detected [10,28—30]. The hydrochloride was obtained in pure form from the final hydrolysis mixture by partial neutralization to pH 0.5 [31]. Variants of this approach, used for the preparation of the racemic compound, followed the same route via the a-acylamino-a-p-aminobenzyl malonic ester III [10,28—30,32,33] or the hydantoin IV [12]. 

The a-(p-nitrophenyl)-a-ethyl-glutarimide starting material can be prepared as follows 217 g of a-phenyl-a-ethyl-glutarimide are dissolved in 800 g of concentrated sulfuric acid with subsequent cooling to about -10°C and nitration is carried out at -10°C to +10°C by slow addition of a mixed acid consisting of 110 g of concentrated sulfuric acid and 110 g of 63% nitric acid. The nitration solution is stirred into ice, the separated nitro compound taken up in methylene or ethylene chloride, the solution washed with water and sodium carbonate solution until neutral and the solvent evaporated under vacuum. The residue is crystallized from methanol or ethyl acetate, whereby a yellowish crystal powder of MP 128-136°C is obtained in a yield of about 85% which consists for the most part of a-(p-nitrophenyl)-a-ethyl-glutarimide. By recrystallization from methanol the pure p-nitrophenyl compound is obtained of MP 137-139°C. From the residues of the mother liquors a small quantity of the isomeric a-(o-nitrophenyl)-a-ethyl-glutarimide of MP 170-172°C can be obtained. 

Oxidation of the ethylene acetals of 3-aryl-3-oxo-2-propyl phenyl telluriums, which were prepared from the acetals of 3-aryl-3-oxo-2-bromopropane and arenetellurolates, with 3-chloroperoxybenzoic acid in methanol at 20° produced hydroxyethyl 2-arylpropanoates2. Tellurones were postulated as intermediates that experienced a 1,2-aryl shift and the elimination of an aryltelluro moiety. 

Syntheses of acetals of atropaldehyde have been reported previously, but all required either multistep sequences or difficultly accessible starting materials.5,6 Thus the ethylene glycol acetal has been prepared from 2-phenylpropanal in a three-step procedure.5 Ring openings of dihalocyclopropanes to give acetals are well known.7-10 The reaction of l,l-dichloro-2-phenylcyclopropane with methanolic sodium methoxide has been shown to give 1-phenyl-2,2-dimethoxycyclopropane. u... 

Figure 29 Separation of the nonsteroidal anti-inflammatory drugs ibuprofen (peak 1), naproxen (2), ketoprofen (3), and suprofen (4) in anion-exchange CEC mode using a strong anion-exchange monolithic column. Conditions on-column alkylated monolith prepared from mixtures consisting of 8% 2-dimethylaminoethyl methacrylate, 24% 2-hydroxyethyl methacrylate, 8% ethylene dimethacrylate, 20% cyclohexanol, 40% 1-dodecanol UV-initiated polymerization at room temperature for 16 h cfpmode= 1423 nm. Column dimensions inner diameter 0.1 mm, total length 335 mm, effective length 250 mm. Mobile phase 0.4 mol/L acetic acid and 4 mmol/L triethylamine in acetonitrile/methanol (60/40), voltage -25 kV, injection -5 kV for 5 s, temperature 50°C, UV detection at 250 nm. (Reprinted from Ref. 127, with permission.)...

Methyl /3-hydroxypropionimidates (12) (prepared from ethylene cyanohydrin, methanol, and HO) condense with aminoacetaldehyde dimethylacetal (13) to yield an amidine hydrochloride (14) which undergoes ring closure to an imidazole.87 Applications of this reaction have been used in the synthesis of 2-phenylimidazole and its 4-alkyl derivatives,88 some new 2-mercaptoimidazoles,89 and isohistamine .90 Isohistamine [2-(2 -aminoethyl)imidazole], originally reported in error by Jones,01 was prepared in 50% yield by an adaptation of the method of Ellinger and Goldberg92 and proved by NMR spectroscopy to be the authentic compound. The compound prepared... 

Intercalation of poly(ethylene oxide) into a lithium-ion exchanged clay gives an interesting class of layered silicate nanocomposites that are lithium-ion electrolytes. Componnds have been prepared by intercalation from methanol/water solutions and by melt intercalation. Melt intercalation typically gives samples with higher polymer contents than the solution method and with higher lithium-ion conductivity though the conductivity is probably stiU too low for practical applications. 

Carbon-11 labeled BPA, 4, was synthesized from the corresponding aldehyde, 4-boronophenylacetaldehyde, 9. This boronated aldehyde was prepared from commercially available 4-bromophenylacetic acid, 10, in five synthetic steps (Scheme 1). The synthesis was initiated by the borane reduction8 of acid 10 to the 2-(4-boronophenyl)ethyl alcohol, 11. Alcohol 11 was then carefully oxidized9 to aldehyde 12. In the next step, 4-bromophenylacetaldehyde, 12, was refluxed with ethylene glycol in the presence of a catalytic amount ofp-toluenesulfonic acid to obtain the corresponding acetal 13.10 The boronic acid moiety was introduced at the para position of the phenyl ring by the reaction with butyllithium followed by triisopropyl borate" to obtain the 4-bronophenylacetaldehyde ethylene acetal, 14. In the final step of the synthesis, acetal 14 was treated with concentrated hydrochloric acid in methanol as solvent to obtain the desired precursor, 4-boronophenylacetaldehyde, 9, for the synthesis of carbon-11 labeled BPA, 4, Scheme 2. 

Etherification. With the use of poly(ethylene glycol) [PEG] as a phase-transfer catalyst (PTC), diaryloxymethanes are readily prepared from ArOK and CHjCl in methanol at room temperature. The same catalyst is used in a synthesis of triaryl cyanurates from cyanuric chloride. 

The catalysts were cationic palladium-phosphine systems prepared from palladium acetate, an excess of triphenylphosphine (PPh3), and a Bronsted acid of a weakly or noncoordinating anion (e.g., p-tosylate (OTs ) methanol was used as both the solvent and a reactant. An unexpected change in selectivity was observed upon replacement of the excess of PPh3 by a stoichiometric amount of the hidentate l,3-bis(diphenylphosphino)propane (dppp). Under the same conditions, these modified catalysts led to perfectly alternating ethylene/CO copolymers with essentially 100% selectivity [Eq. (2)] [12-14]. 

---