531-35-1Relevant academic research and scientific papers
Syntheses of the racemic jaborandi alkaloids pilocarpine, isopilocarpine and pilosinine
Davies, Stephen G.,Roberts, Paul M.,Stephenson, Peter T.,Thomson, James E.
scheme or table, p. 3509 - 3512 (2009/09/30)
The synthesis of racemic pilocarpine has been achieved in high overall yield. Two alternative approaches for the formation of the γ-butyrolactone ring are described: the first involves a palladium-catalysed carbonylation reaction of a homopropargylic alco
A practical and scaleable total synthesis of the jaborandi alkaloid (+)-pilocarpine
Davies, Stephen G.,Roberts, Paul M.,Stephenson, Peter T.,Storr, Helen R.,Thomson, James E.
experimental part, p. 8283 - 8296 (2009/12/28)
The total synthesis of (+)-pilocarpine (as its nitrate salt) has been achieved in nine steps and 30% overall yield starting from racemic 2-(2′,2′-dimethoxyethyl)propane-1,3-diol, which was desymmetrised via an enzymatic protocol. A high yielding synthesis of a key α-ethylidene lactone precursor has been developed, which involves the palladium-catalysed decarboxylation/carbonylation of a 1,3-dioxan-2-one for formation of the γ-butyrolactone ring. Subsequent hydrogenation of the α-ethylidene lactone introduces the C(3)-stereochemistry to give a 72:28 mixture of (+)-pilocarpine and (+)-isopilocarpine, which are readily separable via recrystallisation of the (+)-pilocarpine nitrate salt.
Evaluation of monolithic C18 HPLC columns for the fast analysis of pilocarpine hydrochloride in the presence of its degradation products
El Deeb,Schepers,Waetzig
, p. 751 - 756 (2007/10/03)
Monolithic Performance C18 HPLC columns (Chromolith Performance RP-18e, Merck) were applied for the determination of pilocarpine hydrochloride in the presence of its degradation products isopilocarpine, pilocarpic acid and isopilocarpic acid. The method was validated using a set of six monolithic columns and compared to a conventional C18 column. The separation of pilocarpine from its degradation products was investigated on monolithic columns at different flow rates from 1 to 9 ml/min. Superior resolution was obtained using monolithic columns over the conventional C18 column at the same flow rate of 1 ml/min with a total run time of 9 min compared to 13.5 min for the conventional C18 column. Comparable resolution to that obtained in the C18 column (but with better peak symmetry) was obtained at a flow rate of 4 ml/min, although the total run time was reduced to 3.5 min. The precision for both retention time and peak area was investigated over a wide concentration range and found to be equal, or slightly better on Chromolith Performance compared to the conventional column. The overall RSDs% ranged from 0.5% to 1.16% for the conventional column, while for monolithic columns ranged from 0.38% to 0.87% at a flow rate of 1 ml/min and from 0.38% to 0.89% at a flow rate of 4 ml/min. Monolithic column to column reproducibility (n = 6) was measured. The RSDs% ranged from 0.34% to 0.68% for retention time and from 0.3% to 0.94% for peak areas. The detection and quantitation limits on monolithic columns at both flow rates (1 and 4 ml/min) were found to be 0.17 μg/ml and 0.5 μg/ml, compared to 0.31 μg/ml and 1 μg/ml on the conventional column. Monolithic silica rods have also shown the advantage of reducing the time to wash and to re-equilibrate the column. The method showed good linearity and recovery and was found to be suitable for the analysis of pilocarpine hydrochloride formulations.
Convergent diastereoselective synthesis of isopilocarpine by one-pot Michael-addition-alkylation reaction
Braun, Manfred,Buehne, Corinna,Cougali, Dimitrula,Schaper, Klaus,Frank, Walter
, p. 2905 - 2909 (2007/10/03)
The metalated dithiane 7b available from imidazole aldehyde 6 is reacted with furanone 4 and ethyl iodide to give the lactone 8, which forms diastereoselectively. Its configuration is determined to be trans by means of a crystal structure analysis. The desulfurization of 8 leads to the alkaloid isopilocarpine 2 in three steps and 25% overall yield. The relative energies of the diastereomeric alkaloids 1 and 2 have been calculated.
Process for making piloloctam and derivatives thereof
-
, (2008/06/13)
A process of preparing lactam derivatives of pilocarpine is disclosed. The process involves condensation of a dihydroxybutene and alkyl orthoester to form a lactone intermediate which is oxidized to trans-pilopic acid. This lactone ring is reacted with a benzylamine and the benzyl group removed with a novel dissolving metal reduction mixture to yield the key intermediate IV STR1 which can be elaborated to pilolactam through a known sequence of steps.
