Short Communication
SYNTHESIS OF DESGLYMIDODRINE FROM MIDODRINE BY CONVENTIONAL AMIDE
HYDROLYSIS METHOD
S. T. NARENDERAN
1,*
, SRIKANTH JUPUDI
2
, P. VANAJA
2
, S. N. MEYYANATHAN
1
1
Department of Pharmaceutical Analysis,
2
Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Ootacamund, Jagadguru Sri
Shivarathreeshwara University, Mysore 643001, India
Email: mail2narederan@gmail.com
Received: 23 Oct 2017 Revised and Accepted: 21 Dec 2017
ABSTRACT
Objective: The term prodrug involves chemically modifying inert compound which upon administration releases the active parent drug to elicit its
pharmacological response within the body. Acting as a α-adrenergic agonist, desglymidodrine an active metabolite of amide prodrug midodrine is
used for the treatment of essential and orthostatic hypotension. In the present study synthesis of desglymidodrine from midodrine was reported.
Methods: The synthesis was done by the conventional amide hydrolysis method.
Results: A novel synthesis of desglymidodrine was successfully achieved and spectrally elucidated by infrared spectroscopy (IR),
1
H,
13
C nuclear
magnetic resonance (NMR) and mass analysis.
Conclusion: The acquired results were found to be accurate, the synthetic route appeared to be simple, cost-effective and time efficient. Hence the
synthesized desglymidodrine can be as a reference standard for the estimation of the same.
Keywords: Midodrine, Desglymidodrine, Amide hydrolysis.
© 2018 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
DOI: http://dx.doi.org/10.22159/ijpps.2018v10i2.23251
Midodrine (N-glycyl derivative of Desglymidodrine), consisting of
glycine promoiety linking to the amine group, undergoes enzymatic
deglycination to give desglymidodrine. Desglymidodrine is α-adrenergic
receptor agonist which increases the vascular tone and causes elevation
of blood pressure [1]. Chemically midodrine is 2-amino-N-[2-(2, 5-
dimethoxyphenyl)-2-hydroxyethyl] acetamide. It has an empirical
formula of C12H18N2O4 and a molecular weight of 254.28 g/mol [2].
The literature survey revealed different simultaneous estimation
techniques like HPLC [3-6], Spectrometric [7], HPTLC [8] and to the
best of our knowledge, plasma estimation in healthy human
volunteers by UPLC-MS/MS [9] and ascetic patients using liquid
chromatography-tandem mass spectroscopy [10] have been
reported earlier. However, despite the significance of these
analytical efforts in the simultaneous estimation of both prodrug
and its active metabolite no synthetic route has been reported in the
literature for the synthesis of desglymidodrine.
Midodrine is a glycinamide prodrug consisting of a secondary amide
linkage between glycine and desglymidodrine. The possible
mechanism involves attack of hydroxide anion towards positively
charged carbonyl carbon causing localization of the pi bond to
carbonyl oxygen. This leads to the formation of a tetrahedral
intermediate which eventually generates neutral amine and glycine
anion. Here the amide linkage was cleaved by approaching
conventional amide hydrolysis method under basic conditions
giving desglymidodrine.
The midodrine hydrochloride reference standard was supplied by
PAR formulations, Chennai synthetic work was done by procuring
analytical grade solvents. TLC was performed to monitor the
reaction and to determine the purity of the sample product. The
melting point of the synthesized compounds was determined in
open capillaries using veego VMP-1 apparatus and expressed in ˚C
and are uncorrected. The IR spectrum of compounds was recorded
on Shimadzu FT-IR spectrometer using KBr pellet technique and is
expressed in cm
-1
.
1
H-NMR and
13
C-NMR spectra were recorded on
the Agilent (400MHz FT-NMR) using Vnmrj 3.2 V as processing
software. Mass spectra were recorded with Shimadzu LC-MS/MS
8030 system using lab solution software. DSC analysis was carried
out by DSC Q 200 system.
To a solution of midodrine hydrochloride (3 g, 0.01M) in 1N NaOH
solution (200 ml) was refluxed in a water bath for 30 h. The
completion of the reaction was monitored by TLC (n-butanol: water,
4.5:0.5 v/v) and LC-MS/MS. White crystals of desglymidodrine were
obtained upon the addition of sodium hydroxide (q. s) which was
filtered, dried and recrystallized using acetonitrile as solvent (fig. 1).
O
O
OH
NH
NH
2
CH
3
C H
3
O Reflux, 30 hrs
1N, NaOH
O
O
OH
NH
2
CH
3
C H
3
+
O H
NH
2
O
Midodrine
Desglymidodrine
Glycine
Fig. 1: Synthesis of desglymidodrine from midodrine
International Journal of Pharmacy and Pharmaceutical Sciences
ISSN- 0975-1491 Vol 10, Issue 2, 2018