“Place in reactor approximately 140 litres of ethyl acetate and 10kg [of the acid]. Add gradually approximately 2.20 kg of ter-butylamine, heat to reflux until all has dissolved; filter. Cool, filter off and dry. Yield 95%”
“well it works most times.”
“α crystalline form of [the tert-butylamine salt of perindopil] characterised by the following powder X-ray diffraction diagram measured [details specified]”
“A comparison of the results obtained for Experiments 2 and 4 of the Notice with the 25 peaks claimed in the Patent shows that most of the peaks, including the major peak at 9 degrees 2θ, occur at identical angles. Only 3 of the peaks show a noticeable shift from the peaks claimed in the Patent and the other Experiments. This is the kind of result that might be expected from a slight distortion of the crystal structure”
“As a crystallographer, I would not say that they were a different form but that they are a distorted form of that produced in Experiments 1, 2 and 4 of the Repeats.”
“Given all of the above, in my opinion, the results of the Notice and Repeats all show the alpha crystalline form (both distorted and undistorted)”