The synthesis robot

20 December 2016 - 3D-printing

Kitson2016.PNGWe have been critical of Lee Cronin in the past here and here but the recent accomplishment of Kitson, Glatzel & Cronin (doi) as we shall see is remarkable: everything open-sourced! : publication medium (Beilstein J. Org. Chem.) - 3D-printer (RepRap)- printer API (Octoprint) - hardware (Arduino) - software (Python) - synthetic method (McQuade 2016). Everything!

The 3D printer RepRap can build it's own components (!) and it is deployed to build a reactor (15 ml range). Every-day laboratory reactors are made of glass or steel but now plastic? Standard polylactic acid suffers from the chemicals used but polypropylene does not. Disadvantages: poor thermal conductivity requires reactions to run at room temperature and the vessels can not be sealed. Also, no stirring bar! Not printed: the PTFE tubing and needles. In order to control the liquid pumps an Arduino control board was used. Truly everything open-source and affordable!

The reaction sequence: isobutylbenzene, propanoic acid and triflic acid were used in step 1 (a Friedel-Crafts acylation). Next iodobenzene diacetate and trimethyl orthoformate in methanol were brought on-line for a 1,2-aryl migration. The final step consisted of hydrolysis by a potassium hydroxide solution. Total time to reaction completion : 24 hours in a 34% yield.