Technical Implications of Organic Syntheses in Ball Mills - Ball Milling Towards Green Synthesis: Applications, Projects, Challenges - page 264

NH 2 NH 2 NH 2

2 mmol I 2
quartz sand

I I

+ +

NH 2

planetry ball mill
MV, MB = MSZ
5-10 min; 6.7-13.3 Hz

I I

Scheme 10.5 Dry iodination of aniline in a planetary ball mill.

Figure 10.12 Correlation between rotation frequency n rot , milling time t, and yield
of nopinone from oxidation of b-pinene (Scheme 10.3A) in a planetary
ball mill. 10
Reproduced with permission of the Royal Chemical Society.

and 30 min, respectively. Reactions were carried out using milling tools
made from MSZ and applying quartz sand as the milling auxiliary. 73 Cor-
relation in Figure 10.12 indicates a global maximum for the yield at medium
n rot and t ¼ 20 min. Obviously, at lower operating frequencies the energy
entry is too low to induce high reaction rates. Selectivity for

the