2.5- DMF

DMF, Me2NC(0)H. Dimethyl formamide. DMSO, Mc2SO. Dimethyl sulphoxide. 

The idea is to have everything in place before the oxygen is applied. So, lOOg of safrole is in the addition funnel and stirring around in the reaction flask are 10.6g of PdCU, 60g CuCI and 500mL of aqueous dimethylformamide (made by mixing 62.5mL dH20 and 437,5mL DMF). Dimethylformamide (DMF) is not the same as the watched chemical known as N-methylformamide. 

The above reagents (ok the safrole and H2O aren t reagent) are weighed or measured accordingly. The flask is securely clamped into place on the magnetic stirrer. Add the DMF and H2O. Start stirring, and then slowly add the palladium chloride and cuprous chloride. If you add the powders first then the liquids you ll have problems with the stir bar finding a place to spin. 

Dream setup 100 ml of DMF stirring in a flask equipped w/ a sidearm 34 g of safrole was added in 4 portions of about 8 g each. Mixed intimately. Next, 11g of p-benzoquinone was added. Stir rate was upped. Finally, 7 g of pdcl2 was added. A dry addition... 

The last variation we should discuss is about the use of solvent. Ever-bitching about the rarity and price of chemicals, the bees have thrust their anger at the DMF used in this method. TDK sent Strike an article that gives some credence to this [16]. In it the alcohols methanol, ethanol, 1-propanol, ethanediol and others were used in place of DMF with beautifully high yields. Below is the sample experimental from the article Oust picture using safrole or allylbenzene in place of the 1-hexene) ... 

So now we have a modified method where one has ammonia, methylamine or ethylamine freebase saturated in a small amount of DMF. The author next suggested that a power pulse protocol would not necessarily be needed, but that the power output from the microwave should be between 20-40% of full power. Also, the water in the clay would still be needed for the reaction. 

METHOD 3 Things start to look easier and the yields higher when the following method is employed [122]. This method uses a solvent called DMSO (dimethylsulfoxide). Maybe you ve never heard of this solvent but Strike has. It is a common solvent used in all fields of science and although Strike is not 100% sure. Strike believes that one can substitute DMF (dimethylformanilide) for DMSO. 

Iodoallenes can also be prepared in reasonable yields by treatment of secondary acetylenic alcohols with triphenylphosphite-methyl iodide, using DMF as a solvent. One of the -OPh groups is probably first replaced by the propargyloxy group. This intermediate subsequently undergoes attack by iodide on the terminal acetylenic carbon atom, affording the iodoallene in a 1,3-substitution ... 

A solution of 45 g of triphenyl phosphite methiodide in 100 ml of dry di-methylformamide was heated at 100°C and 0.08 mol of the acetylenic alcohol (commercially available) was added in 2 min. After stirring for 30 min at 100°C the mixture was cooled. The flask was equipped for vacuum distillation. On the flask were placed a 25-cm Vigreux column and two stoppers and the column was connected with a condenser and a receiver. The DMF and the iodoallene distilled between... 

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