Sonication to purify solid product- the crude product just disappeared
So I think we have established the problem (thank you @user6376297) . The material still contained enough iPrOH to cause it to dissolve in ether rather than give a filtrable solid because it was not adequately dried. What you need to do with your ethereal solution of product is remove the solvent under reduced pressure then dry the resulting solid under vacuum for at least 5hrs and preferably overnight. Then briefly (~1 min) sonicate the dried solid with ether and collect by filtration.
There is a lesson here: if you have a literature procedure that delivers your desired product in good yield then you follow it - without shortcuts.