Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів
Imidazo[1,5-a]pyridine carboxylic acids are useful building blocks for medical chemistry, but their synthesis scale-up and isolation depend strongly on pH. For zwitterion-prone representatives, a direct titration of acids does not always reveal the basicity of the heteroaromatic center, which is cri...
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| author | Stetsenko, Svitlana V. Grabchuk, Galyna P. |
| author_facet | Stetsenko, Svitlana V. Grabchuk, Galyna P. |
| author_institution_txt_mv | [
{
"author": "Svitlana V. Stetsenko",
"institution": "Taras Shevchenko National University of Kyiv; Enamine Ltd"
},
{
"author": "Galyna P. Grabchuk",
"institution": "Taras Shevchenko National University of Kyiv"
}
] |
| author_sort | Stetsenko, Svitlana V. |
| baseUrl_str | https://ophcj.nuph.edu.ua/oai |
| collection | OJS |
| datestamp_date | 2026-06-10T08:24:31Z |
| description | Imidazo[1,5-a]pyridine carboxylic acids are useful building blocks for medical chemistry, but their synthesis scale-up and isolation depend strongly on pH. For zwitterion-prone representatives, a direct titration of acids does not always reveal the basicity of the heteroaromatic center, which is critical for their further use. Therefore, a series of acids, their corresponding esters, and hydrochlorides were analyzed by the potentiometric titration together with 1H/13C NMR, HPLC, LCMS, and HRMS. The acids showed apparent pKa values of 5.13-6.11, while the esters exposed the basic-center pKa values in the range of 2.75-4.64. NMR data indicate close electronic similarity within the acid/ester pairs, supporting the use of esters as models for acids with masked basicity. |
| doi_str_mv | 10.24959/ophcj.26.360150 |
| first_indexed | 2026-06-11T01:00:23Z |
| format | Article |
| fulltext |
ISSN 2308-8303 (Print) / 2518-1548 (Online) 8
Original Research
http://ophcj.nuph.edu.ua
UDC 54.057:547.89:54.03
S. V. Stetsenko1,2, G. P. Grabchuk1
1 Taras Shevchenko National University of Kyiv, 60 Volodymyrska str., 01033 Kyiv, Ukraine
2 Enamine Ltd, 78 Winston Churchill str., 02094 Kyiv, Ukraine
Determination of Masked Basicity in Imidazo[1,5-a]pyridine
Carboxylic Acids Using Esters
Abstract
Imidazo[1,5-a]pyridine carboxylic acids are useful building blocks for medical chemistry, but their synthesis scale-up and
isolation depend strongly on pH. For zwitterion-prone representatives, a direct titration of acids does not always reveal the
basicity of the heteroaromatic center, which is critical for their further use. Therefore, a series of acids, their corresponding
esters, and hydrochlorides were analyzed by the potentiometric titration together with 1H/13C NMR, HPLC, LCMS, and HRMS.
The acids showed apparent pKa values of 5.13 – 6.11, while the esters exposed the basic-center pKa values in the range of
2.75 – 4.64. NMR data indicate close electronic similarity within the acid/ester pairs, supporting the use of esters as models
for acids with masked basicity.
Keywords: imidazo[1,5-a]pyridine; carboxylic acids; esters; potentiometric titration; pKa; NMR spectroscopy; medicinal
chemistry
С. В. Стеценко1,2, Г. П. Грабчук1
1 Київський національний університет імені Тараса Шевченка,
вул. Володимирська, 60, м. Київ, 01601, Україна
2 ТОВ НВП «Єнамін», вул. Вінстона Черчилля, 78, м. Київ, 02094, Україна
Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах
з використанням естерів
Анотація
Імідазо[1,5-a]піридинкарбонові кислоти є корисними будівельними блоками для медичної хімії, однак масштабуван-
ня їх синтезу та виділення суттєво залежать від pH. Для сполук, схильних до утворення цвітер-йонних форм, пряме
титрування кислот не завжди дозволяє визначити основність гетероароматичного центру, що є критично важливим
для їх подальшого застосування. Тому серію кислот, відповідних естерів та їх гідрохлоридів було досліджено методом
потенціометричного титрування в поєднанні з 1H/13C ЯМР-спектроскопією, HPLC, LCMS та HRMS. Для кислот було ви-
значено значення pKa в межах 5,13 – 6,11, тоді як естери демонстрували значення pKa основного центру в діапазоні
2,75 – 4,64. Дані ЯМР свідчать про близьку електронну подібність у парах кислота/естер, що обґрунтовує використан-
ня естерів як моделей для кислот із замаскованою основністю.
Ключові слова: імідазо[1,5-a]піридин; карбонові кислоти; естери; потенціометричне титрування; pKa; ЯМР-спектроскопія;
медична хімія
Citation: Stetsenko, S. V.; Grabchuk, G. P. Determination of Masked Basicity in Imidazo[1,5-a]pyridine Carboxylic Acids Using Esters.
Journal of Organic and Pharmaceutical Chemistry 2026, 24 (2), 8 – 13.
https://doi.org/10.24959/ophcj.26.360150
Received: 10 February 2026; Revised: 3 May 2026; Accepted: 8 May 2026
Copyright© 2026, S. V. Stetsenko, G. P. Grabchuk. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0).
Supporting information: Potentiometric titration protocol and datasets, all 1H and 13C NMR spectra, HPLC, LCMS, and HRMS data for all
samples analyzed.
Funding: The work was funded by the National Research Foundation of Ukraine (the grant number 0126U003788; the NRFU registration
number 2025.07/0435).
Conflict of interests: The authors have no conflict of interests to declare.
ISSN 2308-8303 (Print) / 2518-1548 (Online) 9
Journal of Organic and Pharmaceutical Chemistry 2026, 24 (2)
■ Introduction
Imidazo[1,5-a]pyridine is a versatile fused
aza-heterocyclic scaffold that continues to attract
attention because of its broad functional relevan-
ce in both materials-oriented and medicinal che-
mistry research [1]. Representative biologi-
cally active series based on this core include
cannabinoid CB2 agonists [2], spleen tyrosine
kinase inhibitors [3], mitogen-activated pro-
tein kinase (MEK) inhibitors [4], 5-HT4 recep-
tor partial agonists [5], and the GCN2 activator
HC-7366, which has entered clinical investiga-
tion [6] (Figure 1). At the same time, synthetic
methods for the preparation and functionaliza-
tion of imidazo[1,5-a]pyridines continue to ex-
pand [7, 8]. Regioisomeric carboxylic acids of
this scaffold are especially attractive as build-
ing blocks for further derivatization, includ-
ing amide-coupling-based medicinal chemistry
programs.
However, synthetic accessibility alone is not
sufficient for practical scale-up. In our case, the
isolation and purification of imidazo[1,5-a]pyri-
dine carboxylic acids proved strongly depend-
ent on the products’ ionization state. Therefore,
determining the pH window for the pH-controlled
precipitation is essential for the reproducible
multigram-scale isolation. For such zwitterion-
prone heteroaromatic acids, the protonation of
the ring nitrogen and deprotonation of the car-
boxyl group may overlap under aqueous condi-
tions, so their direct titration does not always re-
veal the basic center pKa needed for the rational
precipitation control. To address this problem,
we analyzed the corresponding esters as model
compounds. Since the ester analogs retain the
same heteroaromatic framework while masking
the exchangeable carboxyl proton, they can
serve as practical probes for the basicity of the
imidazo[1,5-a]pyridine core.
In this short communication, we report the
potentiometric characterization of a set of parent
regioisomeric imidazo[1,5-a]pyridine carboxylic
acids (Figure 2) and the corresponding esters,
supported by 1H/13C NMR, HPLC, LCMS, and
HRMS. The main goal of the work was not syn-
thetic novelty, but rather the determination of
acid-base parameters relevant to the multigram-
scale isolation and purification. It can provide
broad perspectives on such chemotypes for use
as building blocks in MedChem programs.
N
N
O
Cl
Cl
N
O
rCB2 cAMP 11 nm
N
N
Me
ON
N
Me
N
H
N
N
N
N
N
SYI IC50 0.19 nm
N
N
H
N
H
N O
O
HO
F
I
Cell Proliferation EC50
HTC116 35 nM
A3750 2 nM
N
N
iPr
O
NH
N
N
OMe
O
H
H
5HT4R EC50 9.7 nM
I II III IV
Figure 1. Imidazo[1,5-a]pyridines derivatives in medicinal chemistry
N
N
HO
O
N
N
O
OH
N
N
OHO
Impy-1-CO2H Impy-3-CO2H Impy-5-CO2H
N
N
HO
O N
N
HO
O
N
N
O OH
Impy-6-CO2H Impy-7-CO2H Impy-8-CO2H
Figure 2. Structures of the imidazo[1,5-a]pyridine carboxylic acids studied
ISSN 2308-8303 (Print) / 2518-1548 (Online) 10
Журнал органічної та фармацевтичної хімії 2026, 24 (2)
■ Materials and methods
The imidazo[1,5-a]pyridine carboxylic acids
and esters studied were prepared by analogy to
reported procedures [9, 10]. The structures of the
compounds are shown in Figure 2. The acid
Impy-1-CO2H was prepared from the bulk me-
thyl 2-(pyridin-2-yl)acetate (1) in 4 steps, follow-
ing literature protocols [11]. Compound 1 was sub-
jected to nitrosation with NaNO2 in AcOH giving
oxime 2, which was hydrogenated at 1 atm over
10 % Pd/C in methanol to afford 3. The freshly
prepared 3 was used in [5+1] heterocyclization
with DMFDMA in toluene giving Impy-1-CO2Me,
which was subsequently hydrolyzed by NaOH in
EtOH to the final Impy-1-CO2H. The synthesis
of Impy-3-CO2H was initiated from the bulk
2-aminomethylpyridine (4) acylated with ethyl
2-chloro-2-oxoacetate to afford 5, and cyclized in
a TFAA-DCM-Py system giving Impy-3-CO2Et
in accordance with the published protocol [12].
The alkaline hydrolysis to the final Impy-3-CO2H
was performed in accordance with the Gao and
Wang procedure [10]. The acids Impy-5-CO2H
to Impy-8-CO2H were obtained by one general
approach, starting from commercially available
methyl picolinate 6, nicotinates 7 and 9, and iso-
nicotinate 8. All these amines were formylated
by a mixed formic-acetic anhydride in situ gene-
rated from Ac2O in HCO2H in accordance with the
patent procedure [13]. The following heterocycli-
zation to methyl imidazo[1,5-a]pyridine carboxy-
lates, Impy-5-CO2Me to Impy-8-CO2Me, was per-
formed using the protocol recently developed with
the Tf2O-TEA-DCM system at -10 °C, giving the
desired compounds in high preparative yields
[14]. Finally, the alkaline hydrolysis by LiOH in
THF at room temperature by analogy with [15]
gave target acids Impy-5-CO2H to Impy-8-CO2H
in good preparative yields. The reaction se-
quences and yields are shown in Scheme 1.
In the course of this work, it was found that
the above-mentioned literature protocols yielded
the compounds Impy-6-CO2Me and Impy-6-CO2H
with rather high impurity levels, up to 10 – 15 %.
Therefore, these compounds were purified by treat-
ing their ethanol solutions with a saturated solution
of dry HCl in dioxane [16], giving the correspond-
ing analytically pure salts, Impy-6-CO2Me·HCl
and Impy-6-CO2H·HCl, which were isolated and
included in the analytical series. This observa-
tion provided an additional practical example of
the importance of the pH/protonation-state con-
trol during the isolation.
The extent of literature characterization for
these compounds is uneven. Surprisingly, among
all acids, Impy-1-CO2H to Impy-8-CO2H, only
Impy-3-CO2Et [9] and Impy-3-CO2H [10] were ful-
ly characterized. For the compound Impy-5-CO2H,
only 1H NMR spectra in DMSO-d6 were pub-
lished [17]. The compounds Impy-6-CO2H,
Impy-6-CO2Me [15], Impy-7-CO2Me [13],
Impy-7-CO2H [18] were only mentioned in liter-
ature without characterization, and compounds
Impy-5-CO2Me, Impy-8-CO2Me appeared to
be new ones. Therefore, before proceeding with
the study of their properties, we made their full
characterization (see SI file).
N
CO2MeH2N
OMe
O
N
N
1.2 equiv DMFDMA
58 %
N
CO2MeN
OH
N
CO2Me
H2, 1 atm
10 % Pd/C
ethanol, rt, 16h
93%
NaOH, EtOH OH
O
N
N
NaNO2
AcOH/H2O, 1h
90 % 61 %
Impy-1-CO2HImpy-1-CO2Me1 2 3
N
N
O
OEt
N
N
O
OH
NaOH
EtOH - H2O
43 %
N
NH2
N
H
N
O
OEt
O
TFAA, Py/DCM
-10 C, 12h°
91 %
ClCOCO2Et
TEA, DCM
97 %
Impy-3-CO2HImpy-3-CO2Et4 5
N
NH2
MeO2C
N
H
N
MeO2C
H
O
N
N
MeO2C
N
N
HO2C
Tf2
-40 °C, 2h
Impy-5-CO2H*HCl 54 %
Impy-6-CO2H 86 %
Impy-7-CO2H 56 %
Impy-8-CO2H 42 %
LiOH,
THF/H2O (3:1),
rt, 30 min
HCO2 2O
100 °C, rt, 1h
Impy-5-CO2Me 48 %
Impy-6-CO2Me*HCl 93 %
Impy-7-CO2Me 89 %
Impy-8-CO2Me 84 %
1
2
3
4
Position of CO2Me:
6 7 8 91; 2; 3; 4– – – –
Position of CO2Me:
10 – 1: ;99 %
11 2: ;– 98 %
12 3: ;– 95 %
13 – 4: 96 %
1
35
6
7
8
Scheme 1. The synthesis of the imidazo[1,5-a]pyridine carboxylic acids and corresponding esters studied
ISSN 2308-8303 (Print) / 2518-1548 (Online) 11
Journal of Organic and Pharmaceutical Chemistry 2026, 24 (2)
Potentiometric titrations were carried out in
the aqueous medium using a TitroLine® 7000 auto-
matic titrator (SI Analytics/Xylem). Carboxylic
acids and hydrochlorides were titrated with a stan-
dardized aqueous NaOH, whereas neutral ester
derivatives with pKa values below 7 were titra-
ted with a standardized aqueous HCl. The exact
titration protocol, titrant concentrations, sample
masses, pH values, and pointwise pKa calcula-
tions are provided in the SI file. The pKa values
discussed below were estimated from the Hen-
derson–Hasselbalch relationship using the buffer
regions of the respective titration curves.
Potentiometric titrations were carried out
in the aqueous medium using standardized
0.09910 N NaOH and 0.10967 N HCl; the exact
titration protocol was provided in the SI file.
The pKa values discussed below were estimated
from the Henderson–Hasselbalch relationship
using the buffer regions of the respective titra-
tion curves. Since the aim of the present commu-
nication is practical pKa determination rather
than the exhaustive equilibrium modeling, only
the constants directly relevant to the prepara-
tive problem are discussed in the main text.
All compounds were characterized by 1H and
13C NMR spectroscopy, HPLC, LCMS, and HRMS.
These methods were used to confirm the sample
identity and purity before acid–base measurements.
The complete analytical data, including full NMR
spectra and results of chromatographic and high-
resolution mass spectra for all samples, are pro-
vided in the SI file.
■ Results and discussion
A direct potentiometric titration of the car-
boxylic acids afforded apparent pKa values in
the range of 5.13 – 5.91 for the neutral acid se-
ries (Table 1). Thus, compounds Impy-1-CO2H,
Impy-3-CO2H, Impy-7-CO2H, and Impy-8-CO2H
showed pKa values of 5.91, 5.64, 5.66, and 5.18, re-
spectively, while Impy-6-CO2H·HCl isolated as
a hydrochloride showed an apparent pKa of 5.13.
Compound Impy-5-CO2H·HCl, also available as
the hydrochloride, displayed two transitions at
pKa 3.02 and 6.11, illustrating the presence of
overlapping acid-base equilibria in this family.
In preparative terms, these data are sufficient to
describe the deprotonation behavior of the car-
boxyl-containing compounds, but they do not by
themselves provide an unambiguous estimate of
the heteroaromatic basicity.
The corresponding ester analogs solved this
problem. Since they preserve the same imidazo-
[1,5-a]pyridine framework while removing the
carboxylic acid proton, their potentiometric be-
havior is more informative with respect to the pro-
tonation of the ring nitrogen. The relevant basic-
center pKa values are listed in Table 1. Note that
although Impy-3-CO2Et is an ethyl rather than
methyl ester, it was retained as the available ester
analog of the 3-substituted acid; for the present
determination, the essential structural require-
ment is masking of the carboxylic acid proton
while preserving the imidazo[1,5-a]pyridine core.
The isolated hydrochloride Impy-6-CO2Me·HCl
gave a closely related value of 4.47. Taken to-
gether, these results show that the basicity of the
imidazo[1,5-a]pyridine nucleus depends markedly
on the substitution pattern and, for several re-
gioisomers, lies close enough to the carboxyl-
related transition to complicate a direct inter-
pretation of the titration curves of the acids.
Representative overlayed titration curves are
shown in Figure 3.
Table 1. Relevant acid-base constants of the imidazo[1,5-a]pyridine derivatives studied
Compound Form Relevant pKa value(s) Comment
Impy-1-CO2H acid 5.91 apparent pKa of acid
Impy-3-CO2H acid 5.64 apparent pKa of acid
Impy-5-CO2H·HCl acid hydrochloride 3.02; 6.11 two-step ionization
Impy-6-CO2H·HCl acid hydrochloride 5.13 apparent pKa of acid-containing species
Impy-7-CO2H acid 5.66 apparent pKa of acid
Impy-8-CO2H acid 5.18 apparent pKa of acid
Impy-1-CO2Me methyl ester 2.83 basic-center pKa model
Impy-3-CO2Et ethyl ester 2.95 basic-center pKa model
Impy-5-CO2Me methyl ester 4.67 basic-center pKa model
Impy-6-CO2Me·HCl methyl ester hydrochloride 4.47 protonated ester reference
Impy-7-CO2Me methyl ester 4.42 basic-center pKa model
Impy-8-CO2Me methyl ester 4.71 basic-center pKa model
Note: Values are rounded to two decimal places. Full titration worksheets, complete curves, and additional transitions observed outside the main
discussion are given in the SI file
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Журнал органічної та фармацевтичної хімії 2026, 24 (2)
This interpretation is supported by the NMR
data. For the matched acid/ester pairs, the aro-
matic regions of the 1H NMR spectra are very
similar. For example, the pair Impy-1-CO2H/
Impy-1-CO2Me shows closely corresponding aro-
matic signals, and the same tendency is observed
for the pairs Impy-7-CO2H/Impy-7-CO2Me and
Impy-8-CO2H/Impy-8-CO2Me. The 13C NMR
data also show only modest changes in the het-
eroaromatic carbon resonances upon the conver-
sion of CO2H into CO2R. Therefore, the esterifi-
cation does not significantly alter the electronic
structure of the imidazo[1,5-a]pyridine core, and
the esters can be regarded as chemically reason-
able models of the basicity of the corresponding
acids.
An additional qualitative observation comes
from hydrochlorides. In these samples, the aro-
matic signals are shifted downfield relative to the
corresponding neutral compounds, which is con-
sistent with the protonation in the heteroaroma-
tic system. At the same time, the CO2H signal is
absent in the hydrochloride spectra, whereas it
is observed for several neutral acids in DMSO-d6.
Thus, the spectroscopic data are complementary
to the titration data: NMR does not replace the
aqueous pKa determination, but it supports the
protonation-state determinations and validates
the use of esters as model compounds.
From a practical point of view, the most im-
portant conclusion is that the regioisomeric imi-
dazo[1,5-a]pyridine carboxylic acids cannot be
treated as a single analytical class. The 1- and
3-substituted systems have distinctly lower basic-
center pKa values in the corresponding ester se-
ries, whereas the 5- to 8-substituted series clu-
ster around pKa 4.3 – 4.6. As these values approach
the apparent pKa values of the acids themselves,
the direct pH adjustment during work-up can
easily lead to the partial co-precipitation, incom-
plete precipitation, or irreproducible isolation un-
less the underlying paired equilibria are taken
into account. In this respect, the paired analysis
of acids and esters provides not only a structur-
al interpretation, but also a practical guide for
scale-up.
■ Conclusions
A practical acid-base determination for a se-
ries of regioisomeric imidazo[1,5-a]pyridine car-
boxylic acids and corresponding esters has been
obtained. A direct potentiometric titration of acids
provided the apparent pKa values relevant to
Figure 3. Overlayed potentiometric titration curves of Impy-1-CO2H, Impy-1-CO2Me, and Impy-6-CO2Me·HCl; dotted lines show the
corresponding differential curves
ISSN 2308-8303 (Print) / 2518-1548 (Online) 13
Journal of Organic and Pharmaceutical Chemistry 2026, 24 (2)
the carboxyl-containing series, whereas the es-
ter analogs revealed the protonation constants
of the heteroaromatic basic center. The close
similarity of the 1H and 13C NMR patterns with-
in the acid/ester pairs shows that the esters are
appropriate electronic models for this purpose.
The combined titration and spectroscopic data
explain why the direct pKa determination in
acids may be ambiguous and provide a practical
basis for selecting pH windows for the precipita-
tion and purification of these zwitterion-prone
heteroaromatic building blocks.
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Information about the authors:
Svitlana V. Stetsenko, Ph.D. student of the Taras Shevchenko National University of Kyiv; Leading Specialist of the Screening Compounds
Quality Decision-Making Group, Quality Control Department, Enamine Ltd.
Galyna P. Grabchuk (corresponding author), Ph.D. in Chemistry, Associate Professor, Deputy Director for Scientific and Educational Work,
Educational and Scientific Institute of High Technologies, Taras Shevchenko National University of Kyiv; https://orcid.org/0000-0001-
6632-5762; e-mail for correspondence: grabchyk@knu.ua.
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| id | oai:ojs.journals.uran.ua:article-360150 |
| institution | Journal of Organic and Pharmaceutical Chemistry |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2026-06-11T01:00:23Z |
| publishDate | 2026 |
| publisher | National University of Pharmacy |
| record_format | ojs |
| resource_txt_mv | ophcjnupheduua/4e/5fdb8425bb771c950717c7265e4ba84e.pdf |
| spelling | oai:ojs.journals.uran.ua:article-3601502026-06-10T08:24:31Z Determination of Masked Basicity in Imidazo[1,5-a]pyridine Carboxylic Acids Using Esters Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів Stetsenko, Svitlana V. Grabchuk, Galyna P. імідазо[1,5-a]піридин карбонові кислоти естери потенціометричне титрування pKa ЯМР спектроскопія медична хімія imidazo[1,5-a]pyridine carboxylic acids esters potentiometric titration pKa NMR spectroscopy medicinal chemistry Imidazo[1,5-a]pyridine carboxylic acids are useful building blocks for medical chemistry, but their synthesis scale-up and isolation depend strongly on pH. For zwitterion-prone representatives, a direct titration of acids does not always reveal the basicity of the heteroaromatic center, which is critical for their further use. Therefore, a series of acids, their corresponding esters, and hydrochlorides were analyzed by the potentiometric titration together with 1H/13C NMR, HPLC, LCMS, and HRMS. The acids showed apparent pKa values of 5.13-6.11, while the esters exposed the basic-center pKa values in the range of 2.75-4.64. NMR data indicate close electronic similarity within the acid/ester pairs, supporting the use of esters as models for acids with masked basicity. Імідазо[1,5-a]піридинкарбонові кислоти є корисними будівельними блоками для медичної хімії, однак масштабування їх синтезу та виділення суттєво залежать від pH. Для сполук, схильних до утворення цвітер-йонних форм, пряме титрування кислот не завжди дозволяє визначити основність гетероароматичного центру, що є критично важливим для їх подальшого застосування. Тому серію кислот, відповідних естерів та їх гідрохлоридів було досліджено методом потенціометричного титрування в поєднанні з 1H/13C ЯМР-спектроскопією, HPLC, LCMS та HRMS. Для кислот було визначено значення pKa в межах 5,13-6,11, тоді як естери демонстрували значення pKa основного центру в діапазоні 2,75-4,64. Дані ЯМР свідчать про близьку електронну подібність у парах кислота/естер, що обґрунтовує використання естерів як моделей для кислот із замаскованою основністю. National University of Pharmacy 2026-06-10 Article Article application/pdf application/pdf https://ophcj.nuph.edu.ua/article/view/360150 10.24959/ophcj.26.360150 Journal of Organic and Pharmaceutical Chemistry; Vol. 24 No. 2 (2026): Issue in Progress; 8-13 Журнал органической и фармацевтической химии; Том 24 № 2 (2026): Issue in Progress; 8-13 Журнал органічної та фармацевтичної хімії; Том 24 № 2 (2026): Issue in Progress; 8-13 2518-1548 2308-8303 en https://ophcj.nuph.edu.ua/article/view/360150/349944 https://ophcj.nuph.edu.ua/article/view/360150/349945 Copyright (c) 2026 National University of Pharmacy http://creativecommons.org/licenses/by/4.0 |
| spellingShingle | імідазо[1,5-a]піридин карбонові кислоти естери потенціометричне титрування pKa ЯМР спектроскопія медична хімія Stetsenko, Svitlana V. Grabchuk, Galyna P. Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів |
| title | Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів |
| title_alt | Determination of Masked Basicity in Imidazo[1,5-a]pyridine Carboxylic Acids Using Esters |
| title_full | Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів |
| title_fullStr | Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів |
| title_full_unstemmed | Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів |
| title_short | Визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів |
| title_sort | визначення маскованої основності в імідазо[1,5-a]піридинкарбонових кислотах з використанням естерів |
| topic | імідазо[1,5-a]піридин карбонові кислоти естери потенціометричне титрування pKa ЯМР спектроскопія медична хімія |
| topic_facet | імідазо[1,5-a]піридин карбонові кислоти естери потенціометричне титрування pKa ЯМР спектроскопія медична хімія imidazo[1,5-a]pyridine carboxylic acids esters potentiometric titration pKa NMR spectroscopy medicinal chemistry |
| url | https://ophcj.nuph.edu.ua/article/view/360150 |
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