Acetylene dimethyl sulfate

Etherification. The reaction of alkyl haUdes with sugar polyols in the presence of aqueous alkaline reagents generally results in partial etherification. Thus, a tetraaHyl ether is formed on reaction of D-mannitol with aHyl bromide in the presence of 20% sodium hydroxide at 75°C (124). Treatment of this partial ether with metallic sodium to form an alcoholate, followed by reaction with additional aHyl bromide, leads to hexaaHyl D-mannitol (125). Complete methylation of D-mannitol occurs, however, by the action of dimethyl sulfate and sodium hydroxide (126). A mixture of tetra- and pentabutyloxymethyl ethers of D-mannitol results from the action of butyl chloromethyl ether (127). Completely substituted trimethylsilyl derivatives of polyols, distillable in vacuo, are prepared by interaction with trim ethyl chi oro s il an e in the presence of pyridine (128). Hexavinylmannitol is obtained from D-mannitol and acetylene at 25.31 MPa (250 atm) and 160°C (129). 

Dimethyl sulfate Sulfuric acid, dimethyl ester (8,9) (77-78-1) Isobutyl methyl ketone 2-Pentanone, 4-methyl- (8, 9) (108-10-1) Acetylene, diphenyl- (8) Benzene, , -(l,2-ethynediyl)bis- (9) (501-65-5)... 

Sommelet, 30, 67 Alizarin indicator, 37, 33 Alkylation, of acetylene, 30, 15 of aniline with triphenylcarbinol, 30, 5 of e-caprolactam with dimethyl sulfate,... 

Unsaturated ethers, RCH = CHCH20CHj, have been prepared from the corresponding allylic alcohols and dimethyl sulfate in the presence of sodium amide (60-80%). Acetylenic ethers are made in a similar manner from acetylenic alcohols. The hydroxyethylation of phenols with ethylene sulfite or ethylene carbonate appears to be a promising reaction for the formation of hydroxy ethers of the type ROCH,CHjOH. ... 

Dimethyl carbonate can be used to alkylate phenols, aromatic amines, acetylenes, and active methylene compounds. What other alkylations might be carried out with it that are now performed with iodomethane or dimethyl sulfate ... 

Reaction of acetylene itself with the [HFe(CO)4] anion under pressure gives a 45% yield of a yellow solid of composition Fe2CioH40g, volatile at 70-80° C/0.1 mm [186). For several years the structure of this compound was a mystery. Further work demonstrated its ability to act as a weak acid, forming the air-sensitive anion [Fe2CioH20g] which reacted with dimethyl sulfate to form a dimethyl derivative [187). The parent complex Fe2CioH40g could also be benzoylated with benzoyl chloride in the presence of pyridine [187). 

Methylsulfinyl carbanion (dimsyl ion) is prepared from 0.10 mole of sodium hydride in 50 ml of dimethyl sulfoxide under a nitrogen atmosphere as described in Chapter 10, Section III. The solution is diluted by the addition of 50 ml of dry THF and a small amount (1-10 mg) of triphenylmethane is added to act as an indicator. (The red color produced by triphenylmethyl carbanion is discharged when the dimsylsodium is consumed.) Acetylene (purified as described in Chapter 14, Section I) is introduced into the system with stirring through a gas inlet tube until the formation of sodium acetylide is complete, as indicated by disappearance of the red color. The gas inlet tube is replaced by a dropping funnel and a solution of 0.10 mole of the substrate in 20 ml of dry THF is added with stirring at room temperature over a period of about 1 hour. In the case of ethynylation of carbonyl compounds (given below), the solution is then cautiously treated with 6 g (0.11 mole) of ammonium chloride. The reaction mixture is then diluted with 500 ml of water, and the aqueous solution is extracted three times with 150-ml portions of ether. The ether solution is dried (sodium sulfate), the ether is removed (rotary evaporator), and the residue is fractionally distilled under reduced pressure to yield the ethynyl alcohol. 

Controlled hydrogenation, in a study of the controlled hydrogenation of acetylenes to r/.s-olcfins. Cram and Allinger38 found palladium on barium sulfate with a trace of pure quinoline (synthetic) to be superior to the Lindlar catalyst in reproducibility and ease of preparation (a sample of quinoline from coal tar was found to be unsuitable for this purpose). In one example 19.2 g of dimethyl 5-decynedioate (1) was hydrogenated with use of 0.4 g. of 5% palladium on barium sulfate and 0.4 g. of synthetic quinoline in 100 ml. of methanol. The mildly exothermal reaction ceased abruptly after 20 min., with absorption of exactly one equivalent of hydrogen. 

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