Abstract
When milled together with calcite grains, thiophenol and α,β-unsaturated esters such as acrylic and cinnamic ones readily underwent the Michael-type addition reaction to give the corresponding β-thio esters in high yield. Similarly, malononitrile underwent facile 1,4-conjugative addition reaction to produce the expected dinitrile esters in moderate to good yield. However, nitromethane was quite reluctant to react under similar conditions, though the yield could be somewhat improved by the addition of potassium fluoride. The ball milling methodology was successfully extended to the solvent-free nitration of aromatic polyols, which are readily destroyed by the action of nitric and sulfuric acids. Thus, resorcinol was smoothly nitrated with NaNO3-NaHSO4 under milling conditions to give 4-nitroresorcinol as the main product, accompanied by 2,4-dinitroresorcinol as byproduct, in a good combined yield
