in the series "when chemists were real men" i present 2 more
articles: both are pretty ok yield wise (1000g resp 1100-1150g
allyl iodide from 1000g iodine), both use red phosphorus, the
second one works under CO2 atmosphere. i only bothered to type /
translate the experimental part.
here ya go:
J.Am.Chem.Soc;36;1005(1914)
they claim 1000g allyl iodide from 1000g iodine (i think).
The apparatus consists of a retort, fitted with a funnel having a glass stopper. The retort is connected with a condenser and receiver as usual. The retort is kept dipped in a larger-sized water bath, which can be heated from beneath. Glycerol is next poured into the retort and then the iodine, taking care that all of it drops on the glycerol and that none sticks to the side of the retort. When all the iodine is added, the water bath is heated to boiling. A small piece of phosphorus is then added, the stopper of the funnel being removed temporarily. When this comes into contact with iodine in the hot glycerol, it reacts at once. As a result of the interaction, some ally iodide is formed, which takes up some iodine into solution, A second piece is immediately added and takes part in the reaction in like manner. On continuing the addition of larger pieces of phosphorus, more and more allyl iodide is formed, which, taking up increasing quantities of iodine into solution, facilitates the reaction. After a considerable quantity of phosphorus has been added in this manner, the allyl iodide formed distills off, being heated on the water bath and the heat generated by the reaction. Proceeding in this manner, after the addition of only a few grams of phosphorus (which takes but a short time), large pieces weighing as much as 3-4 g. can be added in quick succession. The operation can, therefore, be very smoothly and quickly completed. Since some isopropyl iodide (b.p. 89°) is invariably produced in this reaction, the mixture boils at less then 100° and, hence, the major part of the distillation is finished on the water bath. The last traces can be distilled off by heating with a constantly moving flame. The allyl iodide is dried and purified in the usual manner.
Just.Lieb.Ann.Chem;185;876(1877)
(transl. from german. note: i'm not sure about some parts of it, see the parts in brackets)
We use 1000 to 2000 g. iodine and per 1000 g. of iodine 3000 g. highly concentrated glycerol and 600 g. of phosphorus. The mixture of glycerol and pulverised iodine is transfered into a big retort equipped with a gas inlet tubed [original: tubulirte retorte !?] which is connected to a recipient equipped with a second neck [original: tubulirten recipienten]. The second neck of the recipient is connected using a glass tube with the fume hood [original: dem luftzug] and the gas inlet tube of the retort with a CO2 apparatus. Once the air inside the apparatus is replaced by CO2, the phosphorus is added in small pieces. The first pieces of phosphorus usually react violently, but the reaction soon calms down; in order to ensure the continuing of the reaction, one has to add bigger pieces of phosphorus or even mildly heat the retort. When all the phosphorus is added, one distills on open flame in a stream of CO2 until the residue starts to foam heavily. The bulk of the allyl iodide is distilled off and the smaller part is gained by rectifying the residue with water vapour. We thus usually obtained 1100-1150 g. C3H5J from 1000g of iodine; iodine of the same quality only gave 700 g. allyl iodide using the method of Claus and Oppenheim.