Tag: M.W:100-200

Quality Control of 5-Hydroxynicotinic acid. The fused heterocycle is formed by combining a benzene ring with a single heterocycle, or two or more single heterocycles. Compound: 5-Hydroxynicotinic acid, is researched, Molecular C6H5NO3, CAS is 27828-71-3, about A new synthesis of calcium N-(5-hydroxynicotinoyl)-L-glutamate and its X-ray diffraction structure. Author is Kiselev, A. V.; Machula, A. A.; Efimov, S. I.; Pashkova, E. B.; Stovbun, S. V..

A new synthesis of N-(5-hydroxynicotinoyl)-L-glutamic acid via a 5-hydroxynicotinic acid imidazolide intermediate has been developed. Its calcium salt (Ampasse) has been synthesized and its structure was studied by X-ray diffraction anal. The reaction conditions for all stages of the process have been optimized and a method for the purification of the substance has been improved.

Although many compounds look similar to this compound(27828-71-3)Quality Control of 5-Hydroxynicotinic acid, numerous studies have shown that this compound(SMILES:O=C(O)C1=CN=CC(O)=C1), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

Joseph, Abhinav; Rodrigues Alves, Joana S.; Bernardes, Carlos E. S.; Piedade, M. Fatima M.; Minas da Piedade, Manuel E. published an article about the compound: 5-Hydroxynicotinic acid( cas:27828-71-3,SMILESS:O=C(O)C1=CN=CC(O)=C1 ).COA of Formula: C6H5NO3. Aromatic heterocyclic compounds can be classified according to the number of heteroatoms or the size of the ring. The authors also want to convey more information about this compound (cas:27828-71-3) through the article.

The importance of controlling the crystallization of mols. in specific conformations for the production of crystalline organic materials with highly reproducible physicochem. properties has long been recognized. Using 5-hydroxynicotinic acid (5HNA) as a model the following two questions were addressed in this work: (i) is it possible to promote the crystallization of a tautomeric form dominant in a specific solvent through solvate formation (ii) Does that form persist if the memory of solvation is erased through thermal desolvation. Single crystal X-ray diffraction (SCXRD) anal. indicated that the crystallization of 5HNA from water and DMSO do indeed lead to a monohydrate, 5HNA.H2O, and a monosolvate, 5HNA.DMSO, resp., where the tautomeric form preferred in solution is preserved (zwitterionic in H2O and neutral in DMSO). Subsequent differential scanning calorimetry (DSC), thermogravimetry (TG), powder X-ray diffraction (PXRD), and diffuse reflectance IR Fourier transform (DRIFT) spectroscopy studies indicated that: (i) albeit upon thermal desolvation different solid forms are initially produced, their structures converge over time to that of the 5HNA starting material, hence to a crystal lattice consisting of the same tautomer; (ii) this tautomer corresponds to a zwitterion. The hydrate and solvate forms showed very distinct solvent loss behaviors at 298 K: 5HNA.H2O did not undergo dehydration even when kept under a reduced pressure, while 5HNA.DMSO was only stable for long periods of time if stored in a closed vial. A thermodn. anal. based on DSC and Calvet drop microcalorimetry results allowed to rationalize these observations indicating that: (i) 5HNA.H2O is predicted to spontaneously lose water, even for a relative humidity of 100%, hence its robustness is most certainly of kinetical origin; (ii) 5HNA.DMSO is thermodynamically stable when a saturation DMSO pressure can be established over the sample, but becomes unstable when exposed to an atm. where the solvent is absent. The kinetically easier desolvation of 5HNA.DMSO compared to 5HNA.H2O may be related to the fact that water is isolated in the crystal lattice (isolated site hydrate) while DMSO is placed in channels (channel solvate).

After consulting a lot of data, we found that this compound(27828-71-3)COA of Formula: C6H5NO3 can be used in many types of reactions. And in most cases, this compound has more advantages.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Aminoisoquinolines, -cinnolines, and -quinazolines. (A) The basic strengths and ultraviolet absorption spectra. (B) Infrared spectra》. Authors are Osborn, A. R.; Schofield, K.; Short, L. N..The article about the compound:Isoquinolin-6-olcas:7651-82-3,SMILESS:OC1=CC2=C(C=NC=C2)C=C1).Synthetic Route of C9H7NO. Through the article, more information about this compound (cas:7651-82-3) is conveyed.

cf. following abstract Potentiometric titrations in aqueous solution at 20° with HCl gave the following pKa values. Isoquinolines: unsubstituted (I), 5.40; 3-NH2 (Ia), 5.05; 4-NH2 (Ib), 6.28; 5-NH2 (Ic), 5.59; 6-NH2 (Id), 7.17; 7-NH2 (Ie), 6.20; 8-NH2 (If), 6.06. Cinnolines: unsubstituted (II), 2.29; 3-NH2 (IIa), 3.70; 4-NH2 (IIb), 6.85; 5-NH2 (IIc), 2.70; 6-NH2 (IId), 5.04; 7-NH2 (IIe), 4.85; 8-NH2 (IIf), 3.68. Quinazolines: unsubstituted (III), 3.51; 2-NH2 (IIIa), 4.82; 4-NH2 (IIIb), 5.85; 5-NH2 (IIIc), 3.57; 6-NH2 (IIId), 3.29; 7-NH2 (IIIe), 4.60; 8-NH2 (IIIf), 2.81. In addition pKa values based on calculations from ultraviolet extinction curves were determined for phenanthridine 4.52, its 6-NH2 derivative 6.88, and 6,7-benzoquinazoline (IV) ∼ 5.2. Ultraviolet absorption data for the above bases and their cations in buffered aqueous solutions and of the methochlorides of I, II, and III in H2O were given. I, II, and III showed the 3 main bands characteristic of electronic transitions parallel to the long, short, and long axes of bicyclic systems, and the effect of the position of the NH2 substituent could be correlated fairly well with the shifts of the bands noted in the spectra of their NH2 derivatives II in cyclohexane showed an addnl. low-intensity, longer wavelength (390 mμ) band of an n → π transition which disappeared in water or acid. The bathochromic shift shown in the spectra of the aminoisoquinolines on conversion to the cations indicated that, as with I, the monocations carry the proton on the ring N. Study of the ΔpKa values (relative to I) showed values below 1 for Ib, Ic, and Ie, in which there is no possibility of addnl. ionic resonance in the cations, and above 1 for the 1-NH2 derivative of I and Id, for which addnl. forms are possible, and a neg. value for Ia, which is clearly not increased in stability by a possible ο-quinonoid resonance form (see the following abstract for If). The bathochromic shifts in the spectra of the aminocinnolines on cation formation again indicated that proton attachment is to the ring N. By analogies to the quinoline and isoquinoline series, ΔpKa values indicated that N1 is the predominant basic center in IIb, IIe, and probably IIc, while N2 is the basic center for IId and IIf (the spectra of If and IIf are similar). From the values of ΔpKa for IIa, the basic center is considered to be N2, although it contrasts strongly with Ia. Cationization of III caused a marked hypsochromic shift in contrast to the more usual slight bathochromic shift for other heterocyclic bases, and some modification of the aromatic system, possibly a 3,4-hydration, is assumed. Ultraviolet studies on cation formation of the aminoquinazolines indicated no hydration for IIIa and IIIb (similar to 2- and 4-aminoquinoline), IIIc, IIIe, and IIIf, while IIId is presumably hydrated. Considering the change on cationization of III and the increased base strength of 3,4-dihydroquinazolines relative to the quinazolines, choice of a basic center by correlation with ΔpKa values is difficult, although N1 seems to be favored for IIIb and definite for IIIe. Quinoxaline and its 6-NH2 derivative also showed the usual bathochromic shift on cation formation, while the 5-NH2 derivative seemed to take up the first proton on its NH2 group. Infrared N-H bond stretching frequencies and force constants, indicative of the amount of interaction of the NH2 group with the ring and the electron density at the ring N, were given for Ia-f, IIa-f, IIIa-f, 2-, 4-, and 5-aminopyrimidines, and 5-aminoquinoline in CCl4, CHCl3, and pyridine (some compounds); the effects of electromeric interaction where possible, the lack of interaction between N1 and a C-5 NH2 group, the effect of 2 ring N atoms adjacent to the NH2 group and of intramolecular H-bonding were noted. 1,3-Dichloroisoquinoline (0.5 g.), 25 cc. MeOH, 0.4 g. KOH, and 3 cc. Raney Ni shaken with H, the MeOH evaporated, and the Et2O extract of the residue treated with picric acid in Et2O gave I picrate, m. 225-6°; 1,3-dibromoisoquinoline (V) behaved similarly. Homophthalimide (5 g.) and 50 cc. PBr3 refluxed 5 hrs., the PBr3 evaporated in vacuo, and the residue treated with alkali gave 3.4 g. V, m. 147-7.5° (MeOH). V (3 g.) was converted to 1.75 g. 3-bromoisoquinoline (VI), m. 63-4° (aqueous MeOH). 3-Chloroisoquinoline (8.8 g.), 100 cc. concentrated NH4OH, and 1 g. CuSO4 heated 30 hrs. at 140° in an autoclave, made strongly basic, and extracted with CHCl3 gave 5.3 g. Ia, m. 176-7° (C6H6), similarly prepared from VI. Ib m. 108-9.5° (C6H6-cyclohexane). 5-Nitroisoquinoline (20 g.), 500 cc. MeOH, and 2 g. 5% Pd-C hydrogenated 2 hrs., evaporated, and the residue crystallized from CHCl3-petr. ether gave 93% Ic, m. 129.5-30.5° (C6H6-cyclohexane). m-MeOC6H4CHO (35.5 g.), 18 g. MeNO2, 125 cc. HOAc, and 12.5 g. NH4OAc refluxed 2 hrs. and poured into H2O gave 27 g. m-MeOC6H4CH:CHNO2, m. 91-2° (C6H6), which was not reduced satisfactorily. 1,2,3,4-Tetrahydro-6-methoxyisoquinoline (2.42 g.) and 0.8 g. 30% Pd-C heated 0.25 hr. at 180-90° in a stream of N, extracted with Et2O, the 2.1 g. oily product treated with 3 g. picric acid in 10 cc. Me2CO, the 2.9 g. picrate decomposed with aqueous LiOH, extracted with Et2O, the 1.03 g. product refluxed 2 hrs. with 25 cc. concentrated HBr, evaporated in vacuo, dissolved in 10 cc. H2O, and treated with aqueous Na2CO3 gave 0.85 g. 6-hydroxyisoquinoline (VII), m. 220° (decomposition); dehydrogenation with Raney Ni in naphthalene was unsuccessful. Id, m. 211-12° (C6H6), was prepared from VII. 1,3-Dihydroxy-7-nitroisoquinoline (VIII) (52 g.), m. 291° (decomposition), was prepared from 56 g. 4-nitrohomophthalic acid in ο-C6H4Cl2. VIII (2 g.) and 20 cc. POCl3 heated 4 hrs. on the steam bath, decomposed with ice, and brought to pH 10 gave 1.18 g. 1,3-dichloro-7-nitroisoquinoline, m. 185° (decomposition) (HOAc), but the reaction was not reproducible. 7-Hydroxyisoquinoline (1.25 g.), 4 cc. NH4SO3 (concentrated NH4OH saturated with SO2), and 20 cc. concentrated NH4OH 16 hrs. at 140-50° gave 1.1 g. Ie, m. 203-5° (C6H6) after sublimation at 150°/0.3 mm. Ic (4.8 g.) in 12 cc. concentrated HBr and 13 cc. H2O diazotized at 0° with 2.3 g. NaNO2 in 15 cc. H2O, added to 5.8 g. CuBr in 48 cc. HBr at 75°, and let stand 24 hrs. gave 5.1 g. 5-bromoisoquinoline (IX), m. 82-4° (petr. ether). KNO3 (2.4 g.) in 20 cc. concentrated H2SO4 added during 5 min. to 4.15 g. IX in 24 cc. concentrated H2SO4, the mixture let stand 1 hr. at room temperature, poured on ice, and made alk. with NH4OH gave 5.05 g. 5-bromo-8-nitroisoquinoline (X), m. 139-41° (MeOH). 5-Chloro-8-nitroisoquinoline (2 g.) and 12 g. NH4OAc added to 2 g. 6% Pd-CaCO3 in absolute MeOH (previously shaken with H), hydrogenated 1 hr., the filtered solution acidified with concentrated HCl, the MeOH evaporated in vacuo, the residue in H2O made alk. with saturated Na2CO3, and extracted with CHCl3 gave 1.02 g. If, m. 171-2° (EtOAc); use of NaOAc in the reduction gave lower yields of If while reduction with Pd-C in MeOH in the presence of NaOAc gave 8-amino-5-chloroisoquinoline, from which the Cl was not removed on Raney Ni hydrogenation in alk. solution; hydrogenation of X in MeOH over Pd-CaCO3 gave colored intermediate products, while reduction of X in the presence of KOH gave a small yield of If. 2-Chloroquinazoline (0.5 g.) added slowly to 0.4 g. KOH in 5 g. PhOH, the mixture heated 3 hrs. at 70°, and made alk. gave 0.58 g. 2-phenoxyquinazoline (XI), m. 124-6° (petr. ether). XI (0.5 g.) and 5 g. NH4OAc heated 2 hrs. at 170-80° and treated with H2O and 2N NaOH gave 0.35 g. IIIa, m. 200° (EtOH). IIIb m. 271-2° (EtOH). 6,2-O2N(H2N)C6H3CO2H (14.84 g.) and 29.4 cc. HCONH2 4.5 hrs. at 155-60° gave 12.2 g. 4-hydroxy-5-nitroquinazoline (XII), m. 252-6° (H2O). XII (7 g.) and POCl3 gave 5.17 g. 4-chloro-5-nitroquinazoline (XIII), m. 142° after sublimation at 140°/0.5 mm. Resublimed XIII (1 g.) in 150 cc. dry MeOCH2CH2OH and 0.5 g. 6% Pd-CaCO3 hydrogenated 0.5 hr., evaporated, oxidized with K3Fe(CN)6, and the product chromatographed gave 0.265 g. IIIc, m. 195-6.5° (C6H6) after sublimation at 160°/1 mm. IIId, m. 213-14° (C6H6), IIIe, m. 190-1° (C6H6) after sublimation at 160°/0.5 mm., and IIIf, m. 150-1° after sublimation at 120°/0.5 mm., were prepared similarly by reduction at atm. pressure with 6% Pd-C. 1-Chloro-7-methoxyphthalazine (XIV) (7.4 g.), m. 142° (decomposition), was obtained by refluxing 8.8 g. 1-OH compound 0.5 hr. with 40 cc. POCl3. XIV (0.5 g.), 0.2 g. red P, and 5 cc. HI refluxed 1 hr., diluted with 5 cc. H2O, evaporated in vacuo, and the residue in 5 cc. H2O adjusted to pH 7 with NH4OH gave 0.3 g. 6-hydroxyphthalazine-0.5H2O, m. 300° (decomposition) (H2O), which was not converted successfully to the 6-NH2 compound XIV refluxed with HBr gave 4,6-dihydroxyphthalazine, m. 310° (decomposition) (H2O). 3,2-H2NC10H6CO2H (10 g.) was converted to 8.5 g. 4-hydroxy-6,7-benzoquinazoline (XV), m. 278° (H2O). XV (1.3 g.) and 20 cc. POCl3 refluxed 2 hrs. gave 0.98 g. 4-chloro-6,7-benzoquinazoline (XVI), m. 176-8° after sublimation at 160°/0.1 mm. XVI (0.4 g.) in 50 cc. MeOCH2CH2OH hydrogenated 1.5 hrs. over 0.5 g. 8% Pd-CaCO3 and the product in H2O oxidized with 1.4 g. K3Fe(CN)6 gave 0.19 g. IV, m. 163-5° (cyclohexane) after sublimation. XVI (0.23 g.) and 25 cc. saturated NH3-MeOH refluxed 2 hrs. gave 4-amino-6,7-benzoquinazoline, m. 365° (decomposition) (EtOH) after repeated sublimation. XVI (2.1 g.) in 100 cc. warm C6H6 added to 2 equivalents NaCH(CO2Et)2 in 100 cc. C6H6, refluxed 3 hrs., let stand overnight, poured into H2O, the organic layer evaporated, and the residue crystallized from EtOH gave 2.29 g. di-Et 6,7-benzoquinazol-4-ylmalonate (XVII), m. 172-5°. XVII (1.5 g.), 0.6 g. KOH, and 60 cc. MeOH refluxed 3 hrs. gave 0.58 g. 6,7-benzoquinazol-4-ylacetate, m. 207-9° (MeOH), hydrolyzed with boiling aqueous NaOH to traces of 4-methyl-6,7-benzoquinazoline-1.5H2O, m. 124-6° (petr. ether). I (5 g.), 10 cc. MeI, and MeOH refluxed 2 hrs. gave I methiodide, m. 160-1.5° (EtOH), which was shaken with 50 cc. H2O and excess freshly precipitated AgCl for 12 hrs., filtered, the filtrate evaporated, and I methochloride crystallized under anhydrous conditions from EtOH-Et2O. Quinoline methochloride, the very deliquescent II methochloride-0.5H2O, and 4-methylcinnoline methochloride-H2O were prepared similarly.

After consulting a lot of data, we found that this compound(7651-82-3)Synthetic Route of C9H7NO can be used in many types of reactions. And in most cases, this compound has more advantages.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

Electric Literature of C9H7NO. So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic. Compound: Isoquinolin-6-ol, is researched, Molecular C9H7NO, CAS is 7651-82-3, about Copper-catalyzed hydrolysis of bromoisoquinolines: preparation of hydroxyisoquinolines.

A complex phenomenon was observed in the process of preparing hydroxyisoquinoline through copper-catalyzed hydrolysis of bromoisoquinoline. The copper (II) complexes of hydroxyisoquinoline (L2Cu.5H2O) were characterized by high resolution mass spectra, thermogravimetric anal., IR, 1H NMR (NMR), and 2D-NMR. The Cu (II) complexes were mononuclear and coordinated with oxygen and nitrogen atom of two hydroxyisoquinoline and five water mols. in which a strong hydrogen bond was present. Two optimized methods were studied to prevent the formation of copper (II) complexes. The isoquinoline with 4, 5, 6, 7, and 8 hydroxyl substitutions were successfully prepared by copper-catalyzed hydrolysis of corresponding bromoisoquinoline and then workup by sodium sulfide or adjusted pH by dry ice or carbon dioxide gas.

In some applications, this compound(7651-82-3)Electric Literature of C9H7NO is unique.If you want to know more details about this compound, you can contact with the author or consult more relevant literature.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

Most of the natural products isolated at present are heterocyclic compounds, so heterocyclic compounds occupy an important position in the research of organic chemistry. A compound: 22426-30-8, is researched, SMILESS is CC(C)(C#N)C(O)=O, Molecular C5H7NO2Journal, Article, Pfluegers Archiv called Reabsorption of monocarboxylic acids in the proximal tubule of the rat kidney. II. Specificity for aliphatic compounds, Author is Ullrich, K. J.; Rumrich, G.; Kloess, S., the main research direction is lactate resorption kidney proximal tubule; fatty acid kidney lactate resorption; aliphatic compound kidney lactate resorption.Category: catalyst-palladium.

The 3.5-s efflux of D-lactate (I) (1 mM) injected into the lumen of the rat late proximal convolution as well as the zero net flux transtubular concentration difference of I, which is a measure of its active transtubular transport rate, were determined The inhibitory potency of small fatty acids and their analogs added to the perfusate at a concentration of 10 mM on both the 3.5-s efflux and, in most cases, the 45-s transtubular concentration difference of I was measured. Small fatty acids from acetate to octanoate inhibit 3.5-s efflux of I, the largest inhibition being exerted by propionate and butyrate. With increasing chain length the inhibitory potency decreased and disappeared with decanoate. Considering the acetate, propionate, and butyrate analogs, introduction of an electron-attracting group such as Cl, Br, I, CN, SH, or N3 on the C2 atom increased the inhibitory potency, compared to the unsubstituted fatty acid. An OH on C2 increased or did not change the inhibition, whereas an OH on C3 reduced or blunted the inhibition. A keto group, as it is present in glyoxylate, prevented inhibition, but pyruvate was inhibitory to the same extent as lactate, and acetoacetate was even more inhibitory than 3-hydroxybutyrate. Cl substitution on C3 preserved the strong inhibitory potency, whereas 4-chlorobutyrate was only sparsely inhibitory. A NH3+ group at any position precludes inhibition. As seen with Cl- or OH-substituted propionate and butyrate, the inhibitory potency increased with decreasing pKa of the compounds Increasing the chain length by a CH3 as from acetate to propionate, from glycolate to lactate, and also from glyoxylate to pyruvate increased the inhibitory potency. When tested against the 3.5-s efflux of L-lactate, the same inhibitory pattern was seen as with I. The transport of chloroacetate, glycolate, and acetoacetate, which were available in a radiolabeled form of high specific activity, was measured directly in 3.5-s efflux studies. It was Na+-dependent and could be inhibited by 10 mM L-lactate. Glyoxylate, on the other hand, which did not inhibit I transport, also did not show a Na+-dependent, L-lactate-inhibitable efflux from the tubular lumen. Apparently, a variety of short-chain fatty acids and their analogs are transported by the same Na+-dependent transport system in the brush border which transports L-lactate and I. The specificity is determined by the mol. size, hydrophobicity of 1 part of the mol., the electron-attracting abilities of substitutes on C-atom 2 or 3, and the charge distribution on the mol.

Compounds in my other articles are similar to this one(2-Cyano-2-methylpropanoic acid)Category: catalyst-palladium, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Nature of the π-electronic spectra of aromatic compounds. II. Calculation of the three π-π* absorptions of conjugated systems by the Hueckel M.O. method》. Authors are Nishimoto, Kichisuke.The article about the compound:Isoquinolin-6-olcas:7651-82-3,SMILESS:OC1=CC2=C(C=NC=C2)C=C1).Recommanded Product: 7651-82-3. Through the article, more information about this compound (cas:7651-82-3) is conveyed.

cf. CA 61, 3817a; 62, 3907d. The absorption wavelengths,1La, 1Lb, and 1Bb, of CHCH, CH2:CH2, C6H6, PhNH2, PhOH, PhF, C10H8 and its α-NH2, α-OH, and α-F derivatives, anthracene and its α-NH2, α-OH, and α-F derivatives, tetracene, pentacene, phenanthrene and its 1-, 2-, 3-, 4-, and 9-OH derivatives, chrysene, picene, 3,4-benzphenanthrene, benzanthracene, pyrene, C5H5N and its 2-, 3-, and 4-OH derivatives, pyridazine, pyrazine, s-triazine, s-tetrazine, quinoline and its mono-OH substituted derivatives, and isoquinoline and its mono-OH derivatives were determined and calculated, and correlated to the Hueckel mol. orbital (H.M.O.) energies. After a small modification, the relations could be applied fairly well to the calculation of the electronic spectra of the α-substituted hydrocarbons and the N-heterobenzenes. The H.M.O. theory was applicable to the prediction of the 3 π-π* absorptions of conjugated systems. Simple correlation equations (given) were particularly useful for the alternant hydrocarbons and their α-substituted derivatives having an auxochromic group and also for some N-heterocycles. The electronic spectra of these compounds were very similar to those of the parent hydrocarbons. The calculations for the β-substituted derivatives did not give good results, although the agreement between the calculated and observed values was to some extent satisfactory. These discrepancies could be attributed to the complicated configuration interaction scheme between the lower excited configurations of the mol.

Compounds in my other articles are similar to this one(Isoquinolin-6-ol)Recommanded Product: 7651-82-3, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Hydroxy- and amino-substituted piperidinecarboxylic acids as γ-aminobutyric acid agonists and uptake inhibitors, published in 1982, which mentions a compound: 27828-71-3, Name is 5-Hydroxynicotinic acid, Molecular C6H5NO3, Reference of 5-Hydroxynicotinic acid.

The syntheses of (3RS,4RS)-4-hydroxypiperidine-3-carboxylic acid, (3RS,5SR-5-hydroxypiperidine-3-carboxylic acid, (3RS,4SR)-4-acetamidopiperidine-3-carboxylic acid and (3RS,5SR)-5-acetamidopiperidine-3-carboxylic acid, related to the specific γ-aminobutyric acid (GABA) uptake inhibitors (RS)-piperidine-3-carboxylic acid (nipecotic acid) and (3RS,5SR)-4-hydroxypiperidine-3-carboxylic acid, are described. (3RS,4SR)-3-Hydroxypiperidine-4-carboxylic acid, related to the specific GABA agonist piperidine-4-carboxylic acid (isonipecotic acid), has been synthesized. The affinity of the compds for the GABA receptors and for the neuronal (synaptosomal) GABA uptake system in vitro has been measured.

Compounds in my other articles are similar to this one(5-Hydroxynicotinic acid)Reference of 5-Hydroxynicotinic acid, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

Le Blanc, Luc M.; Powers, Sean W.; Grossert, J. Stuart; White, Robert L. published the article 《Competing fragmentation processes of β-substituted propanoate ions upon collision induced dissociation》. Keywords: competing fragmentation process beta substituted propanoate ion CID.They researched the compound: 2-Cyano-2-methylpropanoic acid( cas:22426-30-8 ).Name: 2-Cyano-2-methylpropanoic acid. Aromatic heterocyclic compounds can be divided into two categories: single heterocyclic and fused heterocyclic. In addition, there is a lot of other information about this compound (cas:22426-30-8) here.

Rationale : When subjected to collisional activation, gas-phase carboxylate ions typically undergo decarboxylation. However, alternative fragmentation processes dominate when the carboxylate group is located within certain structural motifs. In this work, the fragmentation processes of β-substituted carboxylate ions are characterized to improve correlations between reactivity and structure. Methods : Mass spectra were collected using both ion trap and triple quadrupole mass spectrometers operating in the neg. ion mode; collision induced dissociation (CID) of ions was used to study the relationship between product ions and the structures of their precursor ions. Quantum mech. computations were performed on a full range of reaction geometries at the MP2/6-311++G(2d,p)//B3LYP/6-31++G(2d,p) level of theory. Results : For a series of β-substituted carboxylate ions, a product ion corresponding to the anion of the β-substituent was obtained upon CID. Detailed computations indicated that decarboxylative elimination and at least one other fragmentation mechanism had feasible energetics for the formation of substituent anions differing in their gas-phase basicities. Predicted energetics for anti- and synperiplanar alignments in the transition structures for decarboxylative elimination correlated with the positions of crossover points in breakdown curves acquired for conformationally constrained ions. Conclusions : The feasibility of more than one mechanism was established for the fragmentation of β-substituted propanoates. The contribution of each mechanistic pathway to the formation of the substituent anion was influenced by structural variations and conformational constraints, but mostly depended on the nature of the substituent.

Compounds in my other articles are similar to this one(2-Cyano-2-methylpropanoic acid)Name: 2-Cyano-2-methylpropanoic acid, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic.Yamagishi, Hiroaki; Inoue, Takayuki; Nakajima, Yutaka; Maeda, Jun; Tominaga, Hiroaki; Usuda, Hiroyuki; Hondo, Takeshi; Moritomo, Ayako; Nakamori, Fumihiro; Ito, Misato; Nakamura, Koji; Morio, Hiroki; Higashi, Yasuyuki; Inami, Masamichi; Shirakami, Shohei researched the compound: 2-Cyano-2-methylpropanoic acid( cas:22426-30-8 ).Electric Literature of C5H7NO2.They published the article 《Discovery of tricyclic dipyrrolopyridine derivatives as novel JAK inhibitors》 about this compound( cas:22426-30-8 ) in Bioorganic & Medicinal Chemistry. Keywords: tricyclic dipyrrolopyridine derivative preparation JAK inhibitor immunomodulator transplant bioavailability; Autoimmune diseases; IL-2; Immunomodulator; Janus kinase inhibitor; Organ transplant rejection. We’ll tell you more about this compound (cas:22426-30-8).

Janus kinases (JAKs) play a crucial role in cytokine mediated signal transduction. JAK inhibitors have emerged as effective immunomodulative agents for the prevention of transplant rejection. The authors previously reported that the tricyclic imidazo-pyrrolopyridinone 2 (I) is a potent JAK inhibitor; however, it had poor oral absorption due to low membrane permeability. Here, the authors report the structural modification of compound 2 into the tricyclic dipyrrolopyridine 18a (3-[(3R,4R)-3-(dipyrrolo[2,3-b:2′,3′-d]pyridin-1(6H)-yl)-4-methyl- piperidin-1-yl]-3-oxopropanenitrile ) focusing on reduction of polar surface area (PSA), which exhibits potent in vitro activity, improved membrane permeability and good oral bioavailability. Compound 18a showed efficacy in rat heterotopic cardiac transplants model.

Compounds in my other articles are similar to this one(2-Cyano-2-methylpropanoic acid)Electric Literature of C5H7NO2, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method

Application In Synthesis of 2-Cyano-2-methylpropanoic acid. The protonation of heteroatoms in aromatic heterocycles can be divided into two categories: lone pairs of electrons are in the aromatic ring conjugated system; and lone pairs of electrons do not participate. Compound: 2-Cyano-2-methylpropanoic acid, is researched, Molecular C5H7NO2, CAS is 22426-30-8, about Ionization functions of some cyanoacetic acids. Author is Ives, David J. G.; Moseley, P. G. N..

The thermodynamic functions of ionization of dimethylcyanoacetic and isopropylcyanoacetic acids from 5 to 45° have been determined by an improved conductance method. The data for 4 cyanoacetic acids are compared in relation to the influence of alkyl substitution and the operation of the compensation law.

This literature about this compound(22426-30-8)Application In Synthesis of 2-Cyano-2-methylpropanoic acidhas given us a lot of inspiration, and I hope that the research on this compound(2-Cyano-2-methylpropanoic acid) can be further advanced. Maybe we can get more compounds in a similar way.

Reference:
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method