4. Increasing pressure to atmospheric, emptying the reactor through the drain valve. During the synthesis, samples were taken at a time interval of 15 min, with the last sample taken just after the reactor was emptied. In the first three reactions (Table ) the product was drained of the reactor after observing a large increase in viscosity to avoid gelation. The time of subsequent reactions was determined based on the calculated model. Samples were taken from the moment a homogeneous reaction mixture was obtained. During sample collection, the stirrer was stopped, the pressure was increased to atmospheric, a sample was taken using a glass rod, the stirrer was turned on, and the pressure was reduced. The entire operation lasted no longer than 1 minute, measured from the moment the stirrer was stopped until it was turned on again. Thanks to the registration of process parameters by the software, the actual time of sample collection was determined, and rounded to the nearest minute. In the case of optimal synthesis, samples were not taken during the process; only one sample was examined after the end.