Nalco process

This is the basic reaction of the commercial Nalco process. On the other hand, reduction of alkyl halides at the cathode is often described in general terms as ... 

III. ANODIC ALKYLATION A. A Iky I lead Compounds, The Nalco Process... 

The industrial Nalco process for the production of 11a and 11b was conducted in mixtures of 53 with THF, at 35-40 °C or 40-50 °C and about 2 kg cm pressure, in a cell divided by porous diaphragms and with current densities of 1.5-3.0 A dm at 15-30 V. However, production details are beyond the scope of this Chapter. Effective methods of recovery of 11 from mixtures after or during the electrolysis were elaborated . Of... 

The electrolysis of methylmagnesium chloride in THF at a three dimensional anode consisting of lead pellets is the principal reaction of the NALCO-process, which produces 18.000 tons of Pb(Me)4 per year 617 Another technical process for the preparation of Pb(Me)4 was developed by Ziegler and Lehmkuhl 618 electrolyzing NaAl(Me)4 in diglyme at a lead anode. 

A number of patents have been issued recently on the basic Nalco process and several non-commercial modifications 54-56,225-228,317),... 

The electrochemical synthesis of organometallics (Lehmkuhl, 1973, 1973a) by conducting the electrolysis at a consumable electrode, e.g. as in the Nalco process (39), is again not readily accommodated in a single formal scheme. 

The anodic oxidation of Grignard reagents using reactive metal anodes such as A1 [10,11], Zn [10,12], Mn [12], Cd [10,12], Bi [12], and B [13] is known to give the corresponding organometallic compounds [Eq. (2)]. This reaction has been used for the synthesis of tetraalkyllead on an industrial scale (NALCO process) [14,15]. 

Electrogenerated radicals can also react with other active electrode materials. Reduction of allyl bromide at a tin cathode, or ethyl bromide at lead affords the corresponding organometallic tin or lead compounds in 75% or 90% yield, respectively [177]. The anodic oxidation of ethyl magnesium bromide also generates ethyl radicals that can be trapped at a lead anode. This reaction is the basis of the NALCO process, which until recently has been used to produce tetraethyllead in a technical scale [178]. 

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