ES2923998A1 - NEW WATER SOLUBLE BODIPY DYES THROUGH SIMPLE FUNCTIONALIZATION IN BORON (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

New water-soluble BODIPY dyes by simple boron functionalization. The known hydrophobicity of BODIPYs and their most common analogs constitutes an important limitation to their optimal use in some applications that require solubility in water, for which it is of interest to obtain BODIPYs soluble in water or highly hydrophilic media from precursor BODIPYs. conventional. The invention refers to the structural design, synthetic access and solubility in water of a new group of hydrophilic molecular dyes belonging to the BODIPYs family, which present as advantages the generality and ease of obtaining them from conventional BODIPY dyes (based on F-BODIPY), this preparation implying the minimum disturbance of the photophysical properties of the starting dye, as well as a significant chemical and photophysical robustness, which implies its potential use in photonic, physical and chemical applications in aqueous or highly hydrophilic media. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

NEW BODIPY COLORS SOLUBLE IN WATER THROUGH

SIMPLE FUNCTIONALIZATION IN BORON

The present invention relates to a new set of BODIPY dyes soluble in water or hydrophilic media and their characteristics. It also covers general methods for their efficient preparation from standard BODIPY dyes (4,4-difluoroBODIPYs). Therefore, the invention is encompassed in the field of organic dyes, and their use in photonic and chemical applications that require adequate solubilization in water or hydrophilic media.

TECHNICAL SECTOR

The invention falls within the chemical sector, and more specifically in the field of water-soluble dyes and pigments for advanced photonic applications, including those in the pharmaceutical industry.

BACKGROUND OF THE INVENTION

The BODIPYs (4-bora-3a,4a-diaza-s-indacenes) constitute an important family of fluorescent organic dyes characterized by their high capacity to absorb and emit light in relatively narrow spectral bands, as well as a well-known chemistry that enables the modulation of photophysical properties. This modulation also allows access to triplet photosensitizers, with low emissive capacity, but essential for achieving a wide variety of photochemical processes of interest, such as the generation of reactive oxygen species (ROS). All these factors have promoted the widespread use of BODIPYs and their analogs, such as azaBODIPYs (4-bora-3a,4,8-triaza-s-indacenes) or BOPHYs (diborated chelates derived from 1,2-bis[( pyrrol-2-yl)methylene)hydrazine), as active colorants in a wide variety of photonic applications in various areas of socio-economic impact, such as those related to obtaining cheap and safe energy, environmental sustainability or the health (Z. Shi et al. Chem. Soc. Rev. 2020, 49, 7533-7567; M. Poddar et al. Coord. Chem. Rev. 2020, 421, 213462; AN Bismillah et al. Chem. Soc. Rev. 2021, 50 , 5631-5649;E.Bassan et al.Chem.Sci.

2021, 12, 6607-6628; P. De Bonfils et al. Eur. J. Org. Chem. 2021, 1809-1824).

However, the known hydrophobicity of BODIPYs and their most common analogs constitutes an important limitation to their optimal use in applications that require their solubilization in water or highly hydrophilic media. These applications are generally framed in the field of biosciences in general and biomedicine in particular, and among them the use of BODIPYs as specific biomarkers in fluorescence microscopy and other advanced bioimaging techniques, such as sensors chemicals for the selective determination of analytes in aqueous media, and as potential advanced photosensitizers for photodynamic therapy (S. Kolemen et al. Coord. Chem. Rev. 2018, 354, 121-134; AM Durantini et al. Eur. J. Med Chem 2018, 144, 651-661, D Wu et al Coord Chem Rev 2018, 354, 74-97, ML Agazzi et al J Photochem Photobiol C 2019, 40, 21-48 E. Bodio et al. J. Porphyr. Phtalocyan. 2019, 23, 1159-1183; R. Prieto-Montero et al. Photochem. Photobiol. 2020, 96, 458-477).

So far, the solubilization of BODIPYs in water has been achieved by covalent bonding to different hydrophilic residues, both ionic (ammonium or phosphonium salts, sulfonates, sulfobetaines, phosphonates, carbanions, etc.) and neutral (polyethers, carbohydrates). , peptides, oligonucleotides, etc.) (L. Li et al. J. Org. Chem. 2008, 73, 1963-1970; SL Niu et al. Org. Lett. 2009, 11, 2049-2052; G. Fan et al. Front. Chem. Sci. Eng. 2014, 8, 405-417). In most cases, this solubilizing functionalization is carried out on the carbon positions, one or more, of the BODIPY chromophore (S.-L. Niu et al. Chem. Eur. J. 2012, 18, 7229-7242; A Romieu et al New J Chem 2013, 37, 1016, AB Nepomnyashchii et al J Phys Chem C 2013, 117, 5599-5609, PL Kand et al J Am Chem Soc 2020 J. Jiménez et al . _ _ _ _ J. Org. Chem. 2021, 86, 9181-9188), which leads to the not always desired modification of the photophysical properties of the starting dye (e.g. shift of the absorption and emission bands, modification of the absorption and emission capacities, etc.).

In other cases, this derivatization aimed at achieving BODIPYs that are sufficiently soluble in aqueous media is carried out in stages prior to the construction of the dye chromophore, through the use of precursors suitably functionalized, either with hydrophilic moieties (O. Dilek et al. Bioorganic Med. Chem. Lett. 2009, 19, 6911-6913; S. Zhu et al. Org. Lett. 2011, 13, 438-441; LJ Patalag et al . Angew. Chem. Int. Ed. 2021, 60, 8766-8771), or with reactive functional groups aimed at achieving said residues after the construction of the dye (J. Xu et al. Biosens. Bioelectron. 2014, 56, 58-63; B. Wu et al. Polymer Chem. 2015, 6, 4279-4289; KM Bardon et al.ACS Omega 2018, 3, 13195-13199; M. I§ik et al. Tetrahedron Lett. 2019, 60, 1421-1425; DK Mai et al. Molecules 2020, 25, 3340). In both cases, this approach implies a greater number of synthetic steps to obtain the desired hydrophilic dye, which increases its price.

For all these reasons, the incorporation of solubilizing hydrophilic residues through the boron atom of BODIPYs and their analogs, once these have already been designed and built to exhibit the optimal photophysical properties required for their use in a specific final application, combines chemical and photonic advantages, by allowing greater generality, fewer synthetic steps, and minimal disturbance of the photophysical properties already optimized in the starting dye.

Examples of hydrophilic BODIPY dyes obtained by functionalizing the boron atom in precursor F-BODIPYs (4,4-difluoroBODIPYs) are known. Most of these hydrophilic BODIPYs are based on C-BODIPY (BODIPY with two boron-bonded carbon moieties) involving ethynyl moieties (SL Niu et al. Org. Biomol. Chem. 2011, 9, 66-69; T. Bura et al . al Org Lett 2011, 13, 3072-3075 SL Niu et al Chem Eur J 2012, 18, 7229-7242 A Poirel et al Chem Eur J 2014, 20, 1252 1257; A. Sutter et al. Chem. Eur. J. 2018, 24, 11119-11130), procedures for its preparation having even been patented (CN102300868A, published on 11-28-2011; CN103865289A, published on 06-18-2014; CN105753892A, published 07-13-2016), including derivatives based on azaBODIPY (9-azaBODIPY) (CN106699786A, published 04-16-2019). The preparation of hydrophilic C-BODIPYs that incorporate iodine atoms in their structure as antimicrobial photodynamic agents has also been patented (WO2021169661A1, published on 09-02-2021). However, all these C-BODIPYs and C-azaBODIPYs require the use of organometallic reagents (generally Grignard reagents) to achieve the desired functionalization on the boron atom, generally in combination with high-temperature reaction conditions, which prevents their conversion. general application to starting dyes (F-BODIPYs and analogs) that have functional groups incompatible with said reagents and/or reaction conditions. Furthermore, it is known that these derivatives may exhibit significantly lower chemical and photophysical robustness than the starting F-BODIPYs (Prieto-Castañeda et al., ChemPhotoChem 2019, 3, 75-85). All this constitutes a limit for the general application of this approach (C-BODIPY based on ethynyl) to the achievement of hydrophilic BODIPYs and analogs of BODIPY.

To a lesser extent, examples of water-soluble BODIPY dyes obtained by functionalization in boron with two oxygenated moieties (O-BODIPYs) have been described (A. Blázquez-Moraleja et al. Dyes Pigments 2019, 170, 107545; B. Brizet et al. Org. Biomol. Chem. 2013, 11, 7729-7737), with a single patent describing the preparation of hydrophilic O-BODIPYs that incorporate iodine atoms in their structure as antimicrobial photodynamic agents (WO2021169661A1, published on 02- 09-2021). However, it is well known that these dyes tend to exhibit significantly lower chemical and photophysical robustness than the starting F-BODIPYs (E. Bodio et al. Dyes Pigments 2019, 160, 700-710), which constitutes a limit for the general application of this approach (O-BODIPY) to the achievement of hydrophilic BODIPYs and analogs of BODIPY. In addition, in certain cases the use of severe reaction conditions is required to achieve the desired functionalization on the boron atom, such as high temperatures, use of microwaves, high reagent/dye stoichiometric ratio, etc.

Finally, water solubilization of BODIPY dyes by incorporating them into hydrophilic nanoparticles has also been achieved (e.g., A. Hoji et al. Eur. Polymer J. 2020, 141, 110058), but this approach limits the use of the dye to photonic applications compatible with nano-structures.

For all of the above, it is still of interest to obtain hydrophilic BODIPYs through a simple synthetic procedure and with minimal disturbance of the photophysical properties already optimized in the starting BODIPY dye (precursor).

EXPLANATION OF THE INVENTION

The present invention describes the structural design, synthetic access and water solubility of a new group of hydrophilic molecular dyes belonging to the family of BODIPYs, which present as advantages the generality and ease of obtaining them from conventional BODIPY dyes (based on F-BODIPY), said preparation implying the minimum disturbance of the photophysical properties of the starting dye, as well as a significant robustness. chemical and photophysical as they are based on COO-BODIPY (4,4-diaciloxyBODIPYs).

The inventors have recently described a simple procedure for obtaining COO-BODIPYs (4,4-diaciloxyBODIPYs), a sub-family of O-BODIPYs that has high chemical robustness and photophysical stability, by direct functionalization of the boron atom of the corresponding F-BODIPY with carboxylic acids of different nature under very mild reaction conditions (C. Ray et al. J. Org. Chem. 2020, 85, 4594-4601; C. Ray et al. Chem. Commun. 2020, 56, 13025 13028). This procedure has also been used successfully to obtain COO-BODIPYs based on W-tert-butoxycarbonyl-L-amino acid (M. Wang, et al. J. Org. Chem. 2021, 18030-18041). Interestingly, this procedure has not been used for the generation of COO-BODIPYs soluble in water or highly hydrophilic media by functionalizing conventional BODIPYs (F-BODIPYs) with sufficiently hydrophilic carboxylic acid moieties.

The computational determination of the values of the partition coefficient in n-octanol and water (logP) for these new dyes and the determination of their experimental limits of solubility in water, as well as their photophysical characterization (wavelengths of maximum absorption and emission, molar absorptivity coefficient and fluorescence quantum yield) in different solvents, demonstrate: (1) their hydrophilic character; (2) the minimal variation of its photophysical properties compared to those of the corresponding F-BODIPY; (3) its excellent photophysical behavior in highly hydrophilic media.

The methodology described in the present invention provides an efficient synthesis protocol for the rapid development of cheap and stable hydrophilic dyes, to be used in different photonic, physical and chemical applications that require the solubilization of the dye in water or in highly hydrophilic media. such as biomarkers, chemosensors, agents for phototherapy, microbial photoinactivation, and/or photodiagnosis, or methods of physical and/or chemical manipulation of these dyes.

Therefore, a first aspect of the present invention refers to the design of the new hydrophilic BODIPY dyes, defined by a compound of general formula (I) (hereinafter the compound of the invention):

where Z is independently selected from carbon or nitrogen atom;

R indicates the presence of one or more substituents of an organic or inorganic nature, which may be covalently bonded to any of the 1, 2, 3, 5, 6, 7 and 8 positions of the compound, in such a way that the boratricycle present in the compound of the invention may be referable to that of any F-BODIPY (conventional BODIPY) precursor.

Ri is selected from alkyl substituted with one or more W groups, alkenyl substituted with one or more W groups, alkynyl substituted with one or more W groups, substituted aryl, heteroaryl substituted with one or more W groups, cycloalkyl substituted with one or more W groups. W, and heterocycloalkyl substituted with one or more W groups;

where W is a highly hydrophilic group independently selected from carboxylate (-COOM), sulfonate (-SO3M), phosphonate (-PO3M2 O -POsR'M), ammonium (-NR 'R"R"'X), immonium ( =NR'R"X, including those based on nitrogen heteroaryl), phosphonium (-PR 'R"R"'X), sulfobetaine (-NR'R"(CH2)nS03 ), and polyethylene glycol-based ether ((OCH2CH2) nOR'); R', R" and R'" are independently selected from hydrogen and alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl or heterocycloalkyl; X is selected from any anionic counterion; and M is selected from any cationic counterion.

The term "alkyl" refers, in the present invention, to straight or branched saturated hydrocarbon chains having from 1 to 18 carbon atoms, such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, n-pentyl, n-hexyl, etc. Preferably the alkyl group has between 1 to 6 carbon atoms.

The term "alkenyl" refers, in the present invention, to unsaturated, linear or branched hydrocarbon chains, having from 2 to 18 carbon atoms, containing one or more carbon-carbon double bonds and which may optionally contain a triple bond. eg vinyl, 1-propenyl, allyl, isoprenyl, 2-butenyl, 1,3-butadienyl, etc. Preferably the alkenyl group has between 2 to 6 carbon atoms.

The term "alkynyl" refers, in the present invention, to unsaturated, linear or branched hydrocarbon chains, which have from 2 to 18 carbon atoms, and which contain one or more carbon-carbon triple bonds and which may optionally contain some bond. double, for example, ethylino, propynyl, butynyl, etc. Preferably the alkynyl group has between 2 to 6 carbon atoms.

The term "aryl" refers, in the present invention, to aromatic rings, single or multiple, having between 5 and 18 carbon atoms in the ring part, such as, but not limited to, phenyl, biphenyl, indenyl, phenanthryl , fluorenyl or anthryl. Preferably the aryl group has between 5 to 6 carbon atoms.

The term "heteroaryl" refers, in the present invention, to an aryl, as defined above, that contains at least one S, N or O atom forming part of an aromatic ring.

The term "cycloalkyl" refers, in the present invention, to a stable hydrocarbon radical, monocyclic or bicyclic from 3 to 10 members, which is totally or partially saturated, such as but not limited to cyclobutyl, cyclopentyl, cyclohexyl, norbornyl or adamantyl. .

The term "heterocycloalkyl" refers, in the present invention, to a cycloalkyl, as defined above, which also contains at least one S, N or O atom forming part of a ring.

By "n" refers, in the present invention, to the number of monomeric units that make up an oligomeric or polymeric chain, with n > 1.

In a preferred embodiment, the Ri substituents carry a maximum of two groups hydrophilic w.

In an even more preferred embodiment Ri is independently selected from -(CH2)3NMe3CI and -CH2(0CH2CH2)20Me, -C6H4NMel and -(CH2)2CH(NH3)COO (residue of zwitterionic character based on the free amino acid glycine)

A second aspect of the present invention refers to a first simple process for obtaining the compound of the invention (I), which comprises a reaction between a compound of formula (II), and a carboxylic acid Ri-COOH bearing one or various hydrophilic groups:

where Z. R and R i are as defined above.

The described reaction can be carried out in the presence of an excess of a Lewis acid as its promoter, which can be selected from trimethylsilyl chloride, BCI3, BBr3, AICI3, AIBr3, SnCI4, SnBr4, SiCI4, SiBr4, trimethylsilyl trifluoromethanesulfonate and triisopropylsilyl trifluoromethanesulfonate. The reaction is preferably carried out in the presence of an excess of boron trichloride between 2 and 3 mol equiv.

The described reaction can be carried out in the presence of an excess of a Lewis base as its promoter, which can be selected from dimethylamine, diethylamine, diisopropylamine, triethylamine, morpholine, pyridine, piperazine, piperidine, pyrrolidine, imidazole, N ,N-diisopropylmethanamine, N,N-diisopropylethanamine, 4- (dimethylamino)pyridin, 2,6-dimethylpyridine, 2,6-di-tert-butylpyridine, 2,2,6,6-tetramethylpiperidine, 1,4-diazabicyclo[ 2.2.2]octane, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undecen-7-ene, and 1,5,7-triazabicyclo[4.4.0] dec-5-ene. The reaction is preferably carried out in the presence of an excess of triethylamine between 4 and 18 mol equiv.

The described reaction can be carried out in the presence of an excess of mixtures of Lewis acids and bases as promoter thereof, where the base and the Lewis acid are selected from those described above. Preferably the reaction is carried out in the presence of a binary mixture of BCI3 and triethylamine.

The described reaction can be carried out under an atmosphere of an inert gas such as argon or nitrogen. Preferably the reaction is carried out under an argon atmosphere.

In another preferred embodiment of the process of the invention, the reaction is carried out in a sufficiently polar and aprotic organic solvent, or in a mixture of these solvents, such as, but not limited to, acetonitrile, N,N-dimethylformamide, dimethylacetamide, N- methylpyrrolidine, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dichlorobenzene, ethyl acetate, or acetone, or mixtures of these solvents. In a preferred embodiment, the solvent is dichloromethane or an acetonitrile/dichloromethane mixture in a 1:1 volume ratio.

The described reaction can be carried out at a temperature between -100C and 1500C, preferably the reaction is carried out at room temperature.

In a preferred embodiment, the process of the invention is carried out using (3-carboxypropyl)trimethylammonium chloride, in the presence of 2 mol equiv. of BCI3 and 6 mol equiv. of triethylamine, in dichloromethane or in a mixture of acetonitrile/dichloromethane 1:1 by volume and at room temperature.

Subsequent to the reaction, the obtained compound of formula (I) can be passed through celite, and can be recrystallized or chromatographically purified after evaporating the solvent or mixture of solvents under reduced pressure.

A third aspect of the present invention refers to a second procedure for obtaining the compound of the invention (I), which presents as variations with respect to the previous procedure, involving a carboxylic acid R2-COOH that carries one or more reactive groups G , and an additional synthetic step of post-functionalization:

where Z, R and R i are as defined above;

R2 is independently selected from alkyl substituted with one or more G groups, alkenyl substituted with one or more G groups, alkynyl substituted with one or more G groups, aryl substituted with one or more G groups, and heteroaryl substituted with one or more G groups. ;

where G is a reactive group independently selected from COOGp, -NR'Gp', -NR'R", =NR' (including those based on nitrogenous heteroaryl); and where R' and R" are as defined above; Gp is a carboxylic acid group protecting group which is independently selected from methyl, tert-butyl and benzyl; and Gp' is an amino group protecting group which is preferably selected from (9-fluorenylmethoxy)carbonyl, fer-butoxycarbonyl, (benzyloxy)carbonyl, methylcarbonyl, trifluoroacetyl, benzyl, triphenylmethyl, benzylidenyl and tosyl.

The described post-functionalization can be performed by the following most preferred alternatives:

(A) Protonation of -NR'R", or =NR' heteroaryl, carried out with an excess of a strong acid that is preferably selected from hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, methanesulfonic acid and trifluoromethanesulfonic acid, to generate-NHR'R"X or =NHR'X, respectively, where R', R" and X are as defined above. In a preferred embodiment the acid is hydrochloric acid.

The protonation can be carried out at a temperature between -200C and 500C, in the presence of water or a compatible organic solvent such as ethyl ether, tetrahydrofuran, methanol, ethanol or acetonitrile, or in mixtures of these solvents. In a preferred embodiment the reaction is carried out at room temperature in water, methanol or ethanol.

(B) Alkylation of heteroaryl -NR'R", or =NR', carried out with an excess of an alkylating agent preferably selected from methyl iodide and dimethyl sulfate, to generate -N R 'R "R "'X or =NR'R"X, respectively, where R', R " R '" and X are as defined above. In a preferred embodiment the alkylating agent is methyl iodide.

The alkylation can be carried out at a temperature between -200C and 300C, in the presence of a compatible organic solvent such as dichloromethane, chloroform or 1,2-dichloroethane. In a preferred embodiment the reaction is carried out at room temperature in dichloromethane.

(C) Conventional deprotection of protected carboxyl or amino groups as COOGp and -NR'Gp', respectively; where Gp, Gp' and R' are as defined above. In preferred embodiments Gp is benzyl, and Gp' is (benzyloxy)carbonyl.

The preferred post-functionalization alternative is alkylation of an amine or nitrogenous aromatic heterocycle with methyl iodide, or standard deprotection of a protected glycine residue as CH(NHCbz)COOBn.

Thus, by means of the present invention it is possible to increase the hydrophilic character of any conventional BODIPY (F-BODIPY with any type of substitution in its positions 1, 2, 3, 5, 6, 7 and 8) through the formation of the compound of formula (I), without this significantly affecting the photophysical activity of the dye, nor the positioning of its spectral bands of absorption and emission, thus facilitating the optimal use of BODIPYs dyes in photonic and chemical applications that require their dissolution in water or media. highly hydrophilic.

Throughout the description and claims the word "comprise" and its variants are not intended to exclude other technical characteristics, additives, components or steps. For those skilled in the art, other objects, advantages and characteristics of the invention will be apparent in part from the description and in part from the practice of the invention. The following examples and figures are provided by way of illustration, and are not intended to be limiting of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1. LogP values calculated for the compounds of the invention 3, 4, 6, 9 and 10, for the corresponding F-BODIPYs 1, 2 and 5, and for a known hydrophilic O-BODIPY (11) (A. Blázquez -Moraleja et al. Dyes Pigments 2019, 170, 107545). The molecular structures of the dye of the invention 3 and dye 11 are included.

Figure 2. Normalized UV-Vis absorption and fluorescence spectra of the compounds of the invention 3, 4, 9 and 10, and of the corresponding F-BODIPYs 1 and 2, in methanol ( ca. 2x10.6 M).

Figure 3. UV-Vis absorption and fluorescence spectra (scaled according to their molar absorption and fluorescent efficiency, respectively) of the compounds of the invention 3, 4, 9 and 10, and of the corresponding F-BODIPYs 1 and 2, in water ( ca. 2x10' 6 M). Compounds 1 and 2 were pre-dissolved in a drop of methanol for optimal subsequent dissolution in water, due to its insolubility in the latter solvent.

EXAMPLES

The invention will now be illustrated by means of tests carried out by the inventors where the obtaining of various water-soluble fluorescent dyes of the invention is described, as well as the computational determination of the partition coefficient (logP) of said dyes, their experimental limit of solubility in water at 20 0C, and its photophysical behavior in different solvents, in comparison with referable BODIPY dyes.

Example 1.

Direct synthesis of water-soluble fluorescent dyes 3, 4 and 6.

The preparation of dyes 3, 4 and 6 has been carried out as described in scheme 1. The hydrophilic groups used are: W = NM3CI for 3 and 6; W = (OCH2CH2)OMe for 4.

Scheme 1. Et = ethyl; Me = methyl; Ph = phenyl.

By this procedure, the carboxylic acid-based moiety bearing the hydrophilic moiety W is attached directly to the boron atom of F-BODIPY to generate the corresponding hydrophilic COO-BODIPY.

Synthesis of 3. On a solution of 50.0 mg (0.157 mmol) of commercial F-BODIPY 1 (also known as PM567 or 2,6-diethyl-4,4-difluoro-1,3,5,7,8- pentamethylBODIPY) in 5 mL of MeCN/CH2Cl2 1:1 by volume are added, under argon atmosphere, 0.314 mL BCI3 1 M in CH2CI2 (0.314 mmol of BCI3). The mixture is stirred at room temperature for 5 min (reaction monitoring is monitored by thin layer chromatography analyzing the disappearance of the starting F-BODIPY). Then, 95.4 mg of triethylamine (0.942 mmol) and 114.2 mg (0.629 mmol) of (3-carboxypropyl)trimethylammonium chloride are added to the reaction mixture, and the resulting mixture is stirred for 30 min at room temperature. (The follow-up of the reaction is monitored by thin layer chromatography analyzing the appearance of a fluorescent stain). After the reaction is complete, the solution is purified by elution chromatography (alumina, CH3CN/H20 8:2 by volume) to obtain 86.7 mg of 3 (86%) as a red solid. RF = 0.24 (alumina, CH3CN/H20 8:2). 1H NMR (CDCI3, 300 MHz) ¿>3.35-3.25 (m, 4H), 3.10 (s, 18H), 2.71 (s, 3H), 2.47-2.37 (m , 20H), 1.90 (m, 4H), 1.03 (t, J= 7.6 Hz, 6H) ppm. 13C NMR (CDCI3, 75 MHz) ¿173.6 (C), 150.9 (C), 142.6 (C), 138.1 (C), 134.4 (C), 133.5 (C), 66.8 (t, J ^c,n = 3.0 Hz, CH2), 53.5 (t, J ^c,n = 3.9 Hz, CH), 32.4 (CH2), 19.3 (CH2), 17.9 (CH2), 17.6 (CH3), 15.2 (CH3) , 14.7 (CH3), 12.7 (CH3) ppm. FTIR ^k 3496, 1718, 1557, 1458, 1388, 1188 cm-1. HRMS (ESI+) m/z 285.2155 ([M]+2; calcd for C32H55BN404: 285.2158).

Synthesis of 4 . On a solution of 50.0 mg (0.191 mmol) of the commercial F-BODIPY 2 (also known as PM546 or 4,4-difluoro-1,3,5,7,8-pentamethylBODIPY) in 5 mL of CH2CI2 are added, under argon atmosphere, 0.381 mL BCI31 M in CH2CI2 (0.381 mmol of BCI3). The mixture is stirred at room temperature for 5 min (reaction monitoring is monitored by thin layer chromatography analyzing the disappearance of the starting F-BODIPY). Then, 84.1 mg of triethylamine (0.831 mmol) and 136.0 mg of 2-(2-(methoxyethoxy)ethoxy)acetic acid (0.763 mmol) are added to the reaction mixture and the resulting mixture is stirred for 30 min. at room temperature (the follow-up of the reaction is monitored by thin layer chromatography analyzing the appearance of a fluorescent stain). The mixture is then filtered through celite (celite® S), the solvent is evaporated under reduced pressure, and the residue obtained is purified by elution chromatography (silica gel, CH2CI2/MeOH 95:5) to obtain 68, 3 mg of 4 (62%) as a dark brown sticky solid. R ^f = 0.33 (silica gel, CH2CI2/MeOH 95:5). 1H NMR (CDCl3.300 MHz) 5.98 (s, 2H), 4.06 (s, 4H), 3.65-3.56 (m, 12H), 3.53-3.48 (m, 4H), 3.35 (s, 6H), 2.63 (s, 3H), 2.40 (s, 6H), 2.34 (s, 6H) ppm. 13C NMR (CDCI3.75 MHz) 170.1 (C), 151.3 (C), 142.6 (C), 141.4 (C), 133.7 (C), 121.7 (CH), 72, 0 (CH2), 70.8 (CH2), 70.70 (CH2), 70.66 (CH2), 69.3 (CH2), 59.1 (CH3), 17.7 (CH3), 16.9 (CH3), 14.7 (CH3)ppm. FTIR ^k 1738, 1557, 1205, 1108, 984 cm-1. HRMS (ESI+) m/z 601.2910 ([M+Na]+; calcd for C28H43BN2Oi0Na: 601.2908).

Synthesis of 6. On a solution of 50.0 mg (0.101 mmol) of 1,3,5,7-tetraphenyl-8-aza-F-BODIPY 5 in 5 mL of MeCN/CH2CI21:1 in volume are added, under argon atmosphere, 0.303 mL BCI31 M in CH2CI2 (0.303 mmol of BCI3). The mixture is stirred at room temperature for 30 min (the follow-up of the reaction is monitored by thin layer chromatography analyzing the disappearance of the starting F-BODIPY). Then, 81.5 mg of triethylamine (0.804 mmol) and 109.5 mg (0.603 mmol) of (3-carboxypropyl)trimethylammonium chloride are added to the reaction mixture, and the resulting mixture is stirred for 30 min at room temperature (the follow-up of the reaction monitors by thin-layer chromatography analyzing the appearance of a fluorescent stain). After the reaction, the solution is purified by elution chromatography (alumina, CH3CN/H2O 88:12 by volume) to obtain 41.5 mg of ⁶ (50%) as a blue solid. RF = 0.15 (alumina, CH3CN/H2O 9:1). 1H NMR (MeOD, 300 MHz) ¿8.22-8.15 (m, 4H), 8.01-7.93 (m, 4H), 7.59-7.47 (m, 12H), 7, 26 (s, 2H), 3.09-2.97 (m, 4H), 3.00 (s, 18H), 1.96 (t, J = 6.8 Hz, 4H), 1.75-1.61 (m, 4H) ppm.

13C NMR (MeOD, 75 MHz) ¿173.5 (CO), 159.7 (C), 145.7 (C), 144.3 (C), 133.5 (C), 132.8 (C) , 132.1(CH), 130.9(CH), 130.8(CH), 130.5(CH), 129.8(CH), 129.7(CH), 120.3(CH), ^66.6 (t, 2.7Hz, CH2), 53.5 (t, 4.4Hz, CH3), 32.2 (CH2), 18.9 (CH2) ppm. FTIR ^k 3378, 1516, 1477, 1122 cmr1.

Example 2.

Synthesis, involving post-functionalization, of the water-soluble fluorescent dyes 9 and 10

The preparation of dyes 9 and 10 has been carried out as described in scheme 2. The reactive groups used are: G = CH(NHCbz)COOBn for 7; G = C5H4N for 8. The hydrophilic moieties used are: W = CH(NH3)COO for 9; W = Cs^NMel for 10.

Scheme 2. Cbz = (Benzyloxy)carbonyl; Bn = Benzyl; C5H4N = 4-Pyridyl; Cs^NMel = 1-methylpyridinium-4-yl iodide.5*107

By this procedure, the carboxylic acid-based moiety bearing a reactive moiety G is attached to the boron atom of F-BODIPY to generate a non-hydrophilic COO-BODIPY, as described by C. Ray et al. in J. Org. Chem. 2020, 85, 4594-4601 for similar non-hydrophilic COO-BODIPYs, which is then subjected to a post-functionalization step to obtain the compound of the invention (I).

Synthesis of 9. To a solution of 50.0 mg (0.157 mmol) of the commercial F-BODIPY 1 in 5 mL of CH2Cl2, 0.314 mL of 1 M BCI3 in CH2Cl2 (0.314 mmol of BCI3) are added under an argon atmosphere. The mixture is stirred at room temperature for 5 min (reaction monitoring is monitored by thin layer chromatography analyzing the disappearance of the starting F-BODIPY). Then, 95.4 mg of triethylamine (0.943 mmol) and 233.5 mg (0.314 mmol) of (S)-5-(benzyloxy)4-(((benzyloxy)carbonyl)amino) acid are added to the reaction mixture. -5-oxopentanoic (N-Cbz-D-glutamic acid benzyl ester), and the resulting mixture is stirred for 30 min at room temperature (reaction monitoring is monitored by thin-layer chromatography by analyzing the appearance of a fluorescent spot) . Then the mixture is filtered through celite (celite® S), the solvent is evaporated under reduced pressure, and the residue obtained is purified by elution chromatography (silica gel, CH2Cl2/AcOEt 8:2 by volume) to obtain 125.1 mg ( 78%) of 7 as an orange solid. RF = 0.20 (silica gel, CH2CI2/AcOEt 95:5 by volume). [a]D20 -170.7 (c 0.054, CHCl3). 1H NMR (CDCI3, 300 MHz) 7.41-7.24 (m, 20H), 5.35 (broad d, J = 8.2 Hz, 2H), 5.07 (s, 4H), 5, 04 and 4.96 (AB system, JAB = 12.3 Hz, 4H), 4.40-4.28 (m, 2H), 2.58 (s, 3H), 2.39-2.23 (m , 20H), 2.12-1.98 (m, 2H), 1.97-1.81 (m, 2H), 0.98 (t, J=7.6 Hz, 6H) ppm. 13C NMR (CDCI3, 75 MHz) - 172.4 (C), 171.9 (C), 156.0 (C), 149.9 (C), 140.5 (C), 136.7 (C) , 136.3(C), 135.3(C), 133.1(C), 132.2(C), 128.7(CH), 128.7(CH), 128.6(CH), 128, 5(CH), 128.3(CH), 67.4(CH2), 67.1(CH2), 53.6(CH), 31.5(CH2), 27.4(CH2),17.4 (CH2), 17.3 (CH3), 14.9 (CH3), 14.8 (CH3), 12.5 (CH3) ppm. FTIR v 1718, 1556, 1202, 980 cm-1. HRMS (ESI+) m/z 1043.4594 ([M+Na]+; calculated for CssHesBN^Na: 1043.4590).

Next, a mixture of 30.0 mg (0.029 mmol) of 7 and 2.0 mg of 5% Pd/C in 5 mL of MeOH are stirred at room temperature under hydrogen atmosphere for 5 min. Once the reaction is complete, a stream of nitrogen is passed through the solution to remove the hydrogen, the mixture is filtered to remove the Pd/C, the solvent is evaporated under reduced pressure, and the resulting solid is washed with diethyl ether and with CH2Cl2 to obtain 15.4 mg (92%) of 9 as a dark orange solid. [a]D20 -48.4 (c 0.040 MeOH). 1H NMR (CD3OD, 300 MHz) ¿3.52 (t, J =6.1 Hz, 2H), 2.70 (s, 3H), 2.52-2.45 (m, 4H), 2.45-2 0.38 (m, 6H), 2.385 (s, 6H), 2.377 (s, 6H), 2.04-1.92 (m, 4H), 1.02 (t, J =7.5 Hz, 6) ppm. 13C NMR (CDCI3.75 MHz) ¿174.5 (C), 173.7 (C), 151.0 (C), 142.6 (C), 138.0 (C), 134.4 (C) , 133.4 (C), 55.4 (CH), 32.9 (CH2), 27.6 (CH2), 17.9 (CH2), 17.6 (CH3), 15.2 (CH3), 14.6 (CH3), 12.7 (CH3) ppm. FTIR ^k 3422, 1717, 1627, 1558, 1199, 1026, 981 cm'1.

Synthesis of 10. To a solution of 75.0 mg (0.236 mmol) of the commercial F-BODIPY 1 in 8 mL of CH2Cl2, 0.472 mL of BCI31 M in CH2Cl2 (0.472 mmol of BCI3) are added under an argon atmosphere. The mixture is stirred at room temperature for 5 min (reaction monitoring is monitored by thin layer chromatography analyzing the disappearance of the starting F-BODIPY). Then, 143.3 mg of triethylamine (1.416 mmol) and 142.7 mg (0.944 mmol) of 3-(4-pyridyl)propanoic acid are added to the reaction mixture, and the resulting mixture is stirred for 30 min at room temperature. environment (the follow-up of the reaction monitors by chromatography of thin layer analyzing the appearance of a fluorescent stain). Once the reaction is complete, the mixture is filtered through celite (celite® S), the solvent is evaporated under reduced pressure, and the residue obtained is purified by elution chromatography (silica gel, CH2Cl2/MeOH 95:5) to obtain 130.0 mg (95%) of 8 as an orange solid. RF = 0.14 (silica gel, CH2CI2/MeOH 95:5). 1H NMR (CDCI3, 300 MHz) = 8.42 (broad s, 4H), 7.04 (d, J = 6.1 Hz, 4H), 2.82 (t, J = 7.4 Hz, 4H) , 2.67 (s, 3H), 2.59 (t, J= 7.3 Hz, 4H), 2.34 (s, 6H), 2.31 (c, J= 7.5 Hz, 4H) , 2.14 (s, 6H), 0.98 (t, J= 7.6 Hz, 6H) ppm.

13C NMR (CDCl3.75 MH ^z ) ¿172.1 (C), 150.7 (C), 149.4 (C, CH), 140.8 (C), 136.9 (C), 133.2 (C ), 132.2 (C), 123.9 (CH), 36.0 (CH2), 30.1 (CH2), 17.4 (CH3), 17.3 (CH2), 14.9 (CH3) , 14.8 (CH3), 12.3 (CH3) ppm. FTIR ^k 3401, 1719, 1601, 1556, 1200, 981 cmr1. HRMS (ESI+) m/z 603.3116 ([M+NaE calcd for C34H4iBN404Na: 603.3119).

Next, to a solution of 40.0 mg (0.069 mmol) of 8 in 2 mL of CH2Cl2, 980.0 mg (0.691 mmol) of methyl iodide are added, and the mixture is stirred at room temperature for 24 h, observing the appearance of a solic. Then, 5 mL of diethyl ether is added to the mixture and it is filtered. The solid is washed with pentane (3x25 mL) and diethyl ether (3x25 mL) to obtain 55.9 mg (94%) of 10 as a reddish-orange solid. 1H NMR (MeOD, 300 MHz) = 8.74 (d, J= 6.2 Hz, 4H), 7.92 (d, J= 6.3 Hz, 4H), 4.35 (s, 6H), 3.09 (t, J = 7.2 Hz, 4H), 2.82 (t, J = 7.2 Hz, 4H), 2.68 (s, 3H), 2.40 (c, J = 7 0.6 Hz, 4H), 2.37 (s, 6H), 2.30 (s, 6H), 1.00 (t, J = 7.5 Hz, 6H) ppm.

13C NMR (MeOD, 75 MHz) ¿173.2 (C), 163.4 (C), 150.8 (C), 145.8 (CH), 142.7 (C), 138.2 (C), 134 0.3 (C), 133.5 (C), 129.1 (CH), 48.3 (CH3), 35.6 (CH2), 31.6 (CH2), 17.9 (CH2), 17, 6 (CH3), 15.3 (CH3), 14.7 (CH3), 13.0 (CH3) ppm. FTIR ^k 3454, 1712, 1643, 1552, 1197, 980 cmr1. HRMS (ESI+) m/z 305.1848 ([M+Na]2+; calcd for C36H47BN404: 305.1845). HRMS (ESI') m/z 126.9045 ([M]-calculated for h 126.9045).

Example 3.

Evaluation of the hydrophilic character of dyes 3, 4,6, 9 and 10.

The hydrophilic character of dyes 3, 4, 6, 9 and 10 has been evaluated by computational determination of the corresponding values of the partition coefficient (logP), defined as the logarithm of the quotient of the concentration of a compound in n- octanol relative to its concentration in water, when in a biphasic n-octanol/water mixture once it has reached equilibrium (J. Comer, K. Tam "Lipophilicity Profiles: Theory and Measurement", in Pharmacokinetic Optimization in Drug Research: Biological, Physicochemical, and Computational Strategies, B. Testa H. van de Waterbed, G. Folkers, R. Guy, J. Comer, K. Tam (eds.), Weinheim: Wiley-VCH. 2020, p. 275-304). This determination has been made using the ACD/Percepta platform (ACD/labs, Toronto, Canada), widely used for this purpose due to its recognized ability to predict logP in molecular systems.

Figure 1 shows the computationally determined logP values for dyes 3, 4, 6, 9 and 10, which vary between 2.8 (for 4) and -4.5 (for 3), and where the increase in the hydrophilic character of these compounds compared to the corresponding precursor F-BODIPYs (1, 2 and 5; logP>2.8). Even dye 4, based on PEG (polyethylene glycol) as a solubilizing function and with the least hydrophilic character among the four compounds of the invention tested (highest logP value), surpasses the best referable hydrophilic O-BODIPY (chains PEGs of equal size) described so far (eg, see 11 in Figure 1), which additionally involve more tedious and less efficient syntheses.

Additionally, the solubility limit in water at 200C for dyes 3, 4, 6, 9 and 10 has been established experimentally, being 10.4 M (optimal limit for biological assays, E. Betzig et al. Molecular Cell 2015, 58, 644-659) for the cases of 3, 4, 6 and 9, and even reaching 10.3 M for compound 10, which exceeds the limits of most hydrophilic BODIPYs described in the literature to date (Z. Chen et al. Front. Chem. Sci. 2014, 98, 405-417; R. Weinstain et al. J. Am. Chem. Soc.

2020, 142, 4970-4974).

Example 4 .

Evaluation of the photophysical behavior of 3, 4, 9 and 10 in solvents of different polarity

The excellent photophysical behavior of the dyes of the invention 3, 4, 9 and 10 in water, in relation to the poor behavior exhibited by the corresponding referable dyes based on F-BODIPY (1 and 2) in this solvent, has been evaluated by the comparison of its absorption and fluorescence spectra in methanol (organic solvent) with those obtained in water (Figures 2 and 3, respectively), as well as by the comparison of key photophysical data related to the light absorption and emission capacity in both solvents (Table 1).

Figure 2 shows that dyes 3, 4, 9 and 10 exhibit absorption and fluorescence bands in methanol whose shape and position fully coincide with those of the respective F-BODIPYs 1 (case of 3, 9 and 10) and 2 (case of 3, 9 and 10). of 4) for reference. Satisfactorily, Figure 3 shows that the shape and position of these bands do not vary when the solvent is water for the dyes that are based on the design of the invention (3, 4, 9 and 10), but they do vary drastically. in its precursors 1 and 2 (insoluble in water even in micromolar concentrations).

Additionally, Table 1 also satisfactorily shows that, although the ability to absorb light (measured in terms of molar absorption coefficient, ?rnax) of dyes 3, 4, 9 and 10 in methanol is less than that of the precursors (1 and 2) in this solvent, this capacity is the same, or even higher (£max up to 3.3x104 M'1 cm_1) when water is used as solvent.

Table 1. Maximum absorption (Aab) and fluorescence (Afi) wavelengths; molar absorption coefficients at the maximum (£max) and fluorescence quantum yields ($ of the compounds of the invention 3, 4, 9 and 10, and of the corresponding F-BODIPYs 1 and 2, in methanol and water (2x10' 6M).

* Pre-dissolved in a drop of methanol to facilitate its

subsequent dissolution in water.

Additionally, Table 1 shows that, with the exception of dye 10 (of a highly hydrophilic saline), the emission efficiency (estimated in terms of fluorescence quantum yields $ of the dyes of the invention in methanol does not vary significantly with respect to that exhibited by reference compounds 1 and 2 under identical experimental conditions around 70- 80%), being even higher for the case of 4. However, while the fluorescent capacity of dyes 1 and 2 is nullified in water (Table 1), due to their known high aggregation in this solvent (Rurack et al. ChemPhotochem 2019, 3, 1-13), that of compounds 3, 4, 9 and 10 stays satisfactorily high in this solvent (^about 60-70%).

Claims (1)

1. Compound of general formula (I)

where Z is independently selected from carbon or nitrogen atom; R indicates the presence of one or more substituents of an organic or inorganic nature, which may be covalently bonded to any of the 1,2, 3, 5, 6, 7 and 8 positions of the compound; Ri is selected from alkyl substituted with one or more W groups, alkenyl substituted with one or more W groups, alkynyl substituted with one or more W groups, substituted aryl, heteroaryl substituted with one or more W groups, cycloalkyl substituted with one or more W groups W, and heterocycloalkyl substituted with one or more W groups; and where W is a hydrophilic group independently selected from carboxylate (-COOM), sultanate (-SO3M), phosphonate (-PO3M2 or -POsR'M), ammonium (-NR'R"R"'X), immonium ( =NR'R"X, including heteroaromatic amine salts), phosphonium (-PR'R"R"'X), sulfobetaine (-NR'R"(CH2)nS03), and polyethylene glycol-based ether ((OCH2CH2)nOR '); R', R" and R"' are independently selected from hydrogen and alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl or heterocycloalkyl; X is selected from any anionic contract; and M is selected from any cationic contractan. 2. Compound according to claim 1, where R1 bears a single hydrophilic group W. 3. Compound according to claim 1, where R1 is independently selected from -(CH 2)3NMe3CI, -CH2(0 CH2CH2)20 Me, -Ce^NMel and (CH2)2CH(NH3)COO (zwitterionic moiety based on the free amino acid glycine) 4. Compounds, according to claim 1, of formula 3, 4, 6, 9 and 10.

^OO 10: R, = (CH2)2C5H4NMel 5. Process for obtaining the compound of the invention (I), described according to preceding claim 1, comprising the direct reaction of a compound of formula (II),

with a carboxylic acid Ri-COOH bearing one or more hydrophilic radicals W; and where Z, R, R1 and W are those defined in the preceding claim 1 for the compound of general formula (I). 6. Process for obtaining the compound of the invention (I), described according to claim 1, which comprises the direct reaction of a compound of formula (II), as described in the preceding claim 4, with a carboxylic acid R2-COOH bearing one or more reactive groups G, followed by a post-functionalization step to transform reactive groups G on hydrophilic moieties W; where R2 is selected from alkyl substituted with one or more G groups, alkenyl substituted with one or more G groups, alkynyl substituted with one or more G groups, substituted aryl, heteroaryl substituted with one or more G groups, cycloalkyl substituted with one or more G groups G groups, and heterocycloalkyl substituted with one or more G groups; where G is a reactive group independently selected from COOGp, -NR'Gp', -NR'R", =NR' (including those present on nitrogen-containing heteroaryls); and where R' and R" are as defined above; Gp is a carboxylic acid group protecting group which is independently selected from methyl, tert-butyl and benzyl; and Gp' is an amino group protecting group which is preferably selected from (9-fluorenylmethoxy)carbonyl, tert- butoxycarbonyl, (benzyloxy)carbonyl, methylcarbonyl, trifluoroacetyl, benzyl, triphenylmethyl, benzylidenyl and tosyl. 7. Use of the compound of the invention (I), described according to the preceding claim 1, in photonic applications that require the use of dyes in aqueous or highly hydrophilic media. 12. Use of the compound of the invention (I), described according to previous claim 1, in physical and chemical applications that require the use of dyes in aqueous or highly hydrophilic media. 13. Use of the compound of the invention (I), described according to the preceding claim 1, in procedures that require the manipulation of BODIPY dyes in aqueous or highly hydrophilic media. 14. Use of the compound of the invention (I), described according to the preceding claim 1, in procedures that require the chemical transformation of BODIPY dyes in aqueous or highly hydrophilic media.