A micro-scale filtration was performed in a 25 mL Erlenmeyer flask and the solution was filtered until all of the liquid has been transferred. Fresh tert-butyl methyl ether (2 mL) was used to rinse the flask. The solution was then obtained by using a gentle air stream to dry and yield the crude product.
The first recrystallization was performed using acetone (6.18 mL) and the solution was warmed until all the solids had dissolved. The solution was then cooled at room temperature for 5 minutes, and then was placed in an ice bath for an additional 15 minutes. After cooling in the ice bath, the crystals were obtained via suction filtration.