Peroxides from Grignard reagents

Ingraffia studied the oxidation of the Grignard reagents derived from indole, skatole, and 2-methylindole with hydrogen peroxide and... 

A peroxide-free grade o anhydrous tetrahydrofuran (stabilized by 0.025% of 2,6-di- -butyl-4-methyl phenol) is available currently (1966) from Fisher Scientific Co. in 1-lb. bottles. This product as obtained from freshly opened bottles has been found to be suitable for reactions such as the formation of Grignard reagents in which purity of solvent is critical (du Pont Co., unpublished observations). It is standard practice in at least one laboratory to use only tetrahydrofuran (Fisher) from freshly opened bottles and to discard whatever material is not used within 2-3 days. 

This compound and compounds of a similar type arc obtained by treating the corresponding chlorophenoxarsine with the appropriate Grignard reagent. It is a colourless oil, B.pt. 185° C. at 20 mm., or 198° to 200° C. at 40 mm. When dissolved in an excess of hydrogen peroxide solution, the water evaporated off and the residue recrystallised from benzene, 10 methylphenomnine dihydo oMde, M.pt. 94° C., is obtained. 

Such exchange reactions between mercurials and lithium alkyls and between mercurials and Grignard reagents had previously been demonstrated by Gilman and Jones 49> as well as by Salinger and Dessy 105>. In addition, Daniel and Paetsch 39> carried out a low temperature oxidation of the ylid with molecular oxygen in tetrahydrofuran, producing a soluble peroxide whose presence was detected both by iodometric titration with sodium thiosulfate and by the isolation of formaldehyde from the reaction mixture after hydrolysis of the formocholine intermediate 3 with acid. 

Monodisperse PHOST has become commercially available from Japan. The starting monomer for living anionic polymerization appears to be 4-tert-bu-toxystyrene, which maybe synthesized by reacting a styrenic Grignard reagent with di-tert-butyl peroxide [125]. Deprotection requires a strong acid such as BBr3. 

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