May and Baker

It is important to use recently-prepared pure sodamide, which must be of fine granular form. Old material of irregular lumpy form, even if ground gives poor results, and should not be employed. The sodamide may be prepared as detailed in Section 11,50,j. A satisfactory grade is marketed by May and Baker Ltd. 

Small amounts of pyridine have been purified by vapour-phase chromatography, using a 180-cm column of polyethyleneglycol-4(X) (Shell 5%) on Embacel (May and Baker) at 100°, with argon as carrier gas. The Karl Fischer titration can be used for determining water content. A colour test for pyrrole as a contaminant is described by Biddiscombe et al. [J Ghent Soc 1957 1 954]. 

R. SiiACK, The. Research Ledforatories, May and Baker Ltd, Dagenhmn, B/Ssesc, England (107)... 

The experimental details were kindly provided by the Chemical Research Laboratories of May and Baker Ltd., Dagenham. 

The following materials were used as supplied tributyl tin methacrylate (International Paint pic), 2-ethylhexyl acrylate (Aldrich Chemical Co. Ltd.), methyl methacrylate (ICI pic) sulphur-free xylene and chloroform (May and Baker Ltd.). 

All operations including those in Sections B and C should be carried out in an atmosphere of purified nitrogen and solvents should be free from oxygen or moisture. Magnesium powder (1.20 g, 49 mmol) (May and Baker or Alpha, 50 mesh) is placed in a dry 500-mL three-necked flask equipped with gas inlet, a 250-mL dropping funnel, and a filtration tube attached to a 250-mL Schlenk flask (Fig. 1). The magnesium is suspended in 5 mL of thf to which 0.1 mL of 1,2-dibromoethane is added. 

The apparatus consists of a chromatography column and a flow controller (Fig. 2.141). This figure is reproduced from the original literature report, to illustrate the description of the technique below, but the equipment is commercially available (e.g. Aldrich Chemical Co., May and Baker Ltd). The flow controller is a simple variable bleed device for precise regulation of the elution rate and is constructed from a glass/Teflon needle valve. Eluate fractions are collected in... 

Rhone-Poulenc, May and Baker Laboratory Products Ltd, Liverpool Road, Barton Moss, Eccles, Manchester, M307RT, UK. 

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