The decomposition of alkyl peroxides 127 alkyl sulphate to hydrogen peroxide used has little effect on the yields because, at best, only some 10 % of the sulphate reacts before all the hydrogen peroxide has decomposed. A mixture of 120c. c. 100 volume hydrogen peroxide with a solution of 56 g. potassium hydroxide in 60 c.c. water was prepared, the hydrogen peroxide having been previously cooled to -20° C. The liquid was then cooled in ice and 184 g. (or more) dipropyl sulphate run in with

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... ng. The stirring was continued for 8 hr., after which the liquid was separated and the lower aqueous part was made just acid to methyl red. The upper layer was used again with a fresh lot of alkaline peroxide and the process repeated for five to six runs. The combined aqueous parts were distilled vacuo to half bulk, and the distillate was extracted exhaustively with ether after salting out with ammonium sulphate. The ether extract was dried over sodium sulphate and the ether removed under slightly reduced pressure. The residual liquid was dried over anhydrous copper sulphate and distilled under 2 cm. pressure from a water bath. The fraction boiling at 35° C was collected separately. The yield of propyl hydrogen peroxide was about 1 g. per run. It was stored over anhydrous copper sulphate and redistilled before use. The dipropyl peroxide which was present with unchanged sulphate in the non-aqueous part of the reaction product was obtained by distillation of the mixture at 2 cm. pressure from an oil bath. The bath temperature was taken to 110° C. The distillate was redistilled under reduced pressure, the liquid boiling at 51-53° C at 8 cm. being separately collected. The yield of dipropyl peroxide was about ^ g. per run. Properties of propyl hydrogen peroxide, C3H 7OOH. Iodine liberation (method described in text): 77*8% theoretical. Ele mentary analysis: C46-8% , Hll-2%. (Calc, for 98-5% C3H 7OOH, 1-5% H 20 : C46-8%, H 10-8% .) Density: 22o 0-9040. Ref. index [Na0 ]: 1-3890 at 25-0° C. Becomes glassy at -90° C. Boiling point: 35° at 2cm., 38° at 3 cm. Properties of dipropyl peroxide, C3H 7OOC3H 7. Elementary analysis: C61-3 %, H 11-5 %. (Theory: C60-9 %, H 11-9 %.) Density: 0-8254. Ref. index [N aJ: 1-3911 at 20-5° C, 1-3940 at 16° C.