181289-58-7Relevant articles and documents
Continuous-Flow Synthesis of Tramadol from Cyclohexanone
Monos, Timothy M.,Jaworski, Jonathan N.,Stephens, John C.,Jamison, Timothy F.
, p. 1888 - 1893 (2020/11/24)
A multioperation, continuous-flow platform for the synthesis of tramadol, ranging from gram to decagram quantities, is described. The platform is segmented into two halves allowing for a single operator to modulate between preparation of the intermediate by Mannich addition or complete the fully concatenated synthesis. All purification operations are incorporated in-line for the Mannich reaction. 'Flash' reactivity between meta-methoxyphenyl magnesium bromide and the Mannich product was controlled with a static helical mixer and tested with a combination of flow and batch-based and factorial evaluations. These efforts culminated in a rapid production rate of tramadol (13.7 g°h -1) sustained over 56 reactor volumes. A comparison of process metrics including E-Factor, production rate, and space-time yield are used to contextualize the developed platform with respect to established engineering and synthetic methods for making tramadol.
Simultaneous chiral separation of tramadol and methadone in tablets, human urine, and plasma by capillary electrophoresis using maltodextrin as the chiral selector
Naghdi, Elahe,Fakhari, Ali Reza
, p. 1161 - 1168 (2018/09/06)
The stereoselective analysis and separation of racemic drugs play an important role in pharmaceutical industry to eliminate the unwanted isomer and find the right therapeutic control for the patient. Present study suggests a maltodextrin-modified capillary electrophoresis method for a single‐run chiral separation of two closely similar opiate pain relief drugs: tramadol (TRA) and methadone (MET). The best separation method possible for the both enantiomers was achieved on an uncoated fused‐silica capillary at 25°C using 100 mM phosphate buffer (pH 8.0) containing 20% (w v?1) maltodextrin with dextrose equivalent of 4–7 and an applied voltage of 16 kV. Under optimal conditions, the baseline resolution of TRA and MET enantiomers was obtained in less than 12 minutes. The relative standard deviations (n = 3) of 20 μg mL?1 TRA and MET were 2.28% and 3.77%, respectively. The detection limits were found to be 2 μg mL?1 for TRA and 1.5 μg mL?1 for MET. This method was successfully applied to the measurement of drugs concentration in their tablets, urine, and plasma samples.
Optimization of throughput in semipreparative chiral liquid chromatography using stacked injection
Taheri, Mohammadreza,Fotovati, Mohsen,Hosseini, Seyed-Kiumars,Ghassempour, Alireza
, p. 579 - 588 (2017/09/29)
An interesting mode of chromatography for preparation of pure enantiomers from pure samples is the method of stacked injection as a pseudocontinuous procedure. Maximum throughput and minimal production costs can be achieved by the use of total chiral column length in this mode of chromatography. To maximize sample loading, often touching bands of the two enantiomers is automatically achieved. Conventional equations show direct correlation between touching-band loadability and the selectivity factor of two enantiomers. The important question for one who wants to obtain the highest throughput is “How to optimize different factors including selectivity, resolution, run time, and loading of the sample in order to save time without missing the touching-band resolution?” To answer this question, tramadol and propranolol were separated on cellulose 3,5-dimethyl phenyl carbamate, as two pure racemic mixtures with low and high solubilities in mobile phase, respectively. The mobile phase composition consisted of n-hexane solvent with alcohol modifier and diethylamine as the additive. A response surface methodology based on central composite design was used to optimize separation factors against the main responses. According to the stacked injection properties, two processes were investigated for maximizing throughput: one with a poorly soluble and another with a highly soluble racemic mixture. For each case, different optimization possibilities were inspected. It was revealed that resolution is a crucial response for separations of this kind. Peak area and run time are two critical parameters in optimization of stacked injection for binary mixtures which have low solubility in the mobile phase.
