Category: 18437-58-6

Okuda, Shigenobu published the artcileThe constitution of matrine. XXVI. The constitution of dehydro-α-matrinidine, Safety of 4-Amino-2-picoline, the publication is Pharmaceutical Bulletin (1956), 257-61, database is CAplus.

cf. C.A. 49, 8316f. The decision between the 2 proposed structures of dehydro-α-matrinidine (I), upon which the structure of matrine depends, is based on spectrographic comparisons. Ultraviolet absorption maximum are recorded for: the degradation products of matrine, I, and the 2 bases C₁₂H₁₈N₂, m. 111° and 190°, resp.; the 4-aminopyridine group of 4-H₂N and 4-Et₂N derivatives of C₅H₅N, and 5,7-dimethyl-1,2,3,4-tetrahydro-1,6-naphthyridine (II); the 3-aminopyridine group of 3-H₂N (III) and 3-Me₂N (IV) derivatives of C₅H₅N, and 2,4-dimethyl-5,6,7,8-tetrahydro-1,5-naphthyridine (V); the 2-aminopyridine group of the 2-H₂N derivative of C₅H₅N, and 2,4-dimethyl-5,6,7,8-tetrahydro-1,8-naphthyridine. The solvents used were EtOH, 0.1N NaOH, 0.01N H₂SO₄, 50% H₂SO₄, and concentrated H₂SO₄. The spectra of 2,4-Me(H₂N) and 2,6,4-Me₂(H₂N) derivatives of C₅H₅N were determined in EtOH only. Only II and IV were previously unknown. The synthesis of II will be reported later. Methylation of III with H₂CO and HCO₂H gave IV, b₆ 95°; picrate, m. 179-81°. Study of the spectra led to the following generalizations: the 3-aminopyridine group form their di-salts even in 50% H₂SO₂, whereas the matrine products and the 4-aminopyridine group show the same absorption in 50% as in 0.01N H₃SO₃; I absorbs at much shorter wave lengths than III in EtOH, 0.1N NaOH, and 0.01N H₂SO₂; C₂H₂N₂ both have the same absorption in all solvents, very similar to that of II, and very different from that of V. It is concluded that all 3 matrine degradation compounds have the 4-aminopyridine skeleton, that I is 1-methyl-4,5,6,8,9,10-hexahydropyrido[3,4,5-ij]quinolizine, and that the C₁₂H₁₈N₂ are Me derivatives of 8-propyl-1,2,3,4-tetrahydro-1,6-naphthyridine.

Pharmaceutical Bulletin published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H8N2, Safety of 4-Amino-2-picoline.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Profft, Elmar published the artcilePreparation and pharmacological properties of 1-(4-alkoxy-2-pyridyl)-2-ethylpiperidines, SDS of cas: 18437-58-6, the publication is Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft (1958), 429-36, database is CAplus.

The title compounds in which the alkoxy group was MeO, EtO, PrO, BuO, iso-BuO, AmO, iso-AmO, n-C₆H₁₃O, or n-C₇H₁₅O were prepared and tested for their activity as local anesthetics by surface application of a 1% solution of their HCl salts. The PrO compound was prepared by treating 24 g. 2,4-Me(PrO)C₅H₃N with 12 g. 40% HCHO and 3 drops of HOAc at 190° for 8 h. and working up with Et₂O to give 7 g. 2,4-HOCH₂CH₂(PrO)C₅H₃N (I), yellow oil, b₁₈ 182-6°. I (10 g.) kept with 2 g. KOH for 40 h., some hydroquinone added, and the product vacuum distilled gave 2,4-CH₂:CH(PrO)C₅H₃N (II), b₂₀ 125-7°. II (0.05 mol) heated with 0.033 mol piperidine and 0.0043 mol HOAc for 3 h. on a water bath at 95-110°, then vacuum distilled gave 1-(4-propoxy-2-pyridyl)-2-ethylpiperidine, a golden oil, b₁₆ 200.5°. The other members of the series were prepared in a similar manner. Only the n-C₆H₁₃O and n-C₇H₁₅O analogs showed any significant pharmacol. activity as local anesthetics. Quaternary iodides were also prepared from the 4-alkoxy-2-methylpyridines where the alkoxy group was MeO, EtO, PrO, BuO, or AmO by treatment of 0.02 mol of the picoline with 0.021 mol MeI in 3-5 mL. EtOH for 3 h.

Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H8N2, SDS of cas: 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Suzuki, Yasuyuki published the artcileReactions of 4-pyridine- and 4-quinolinesulfonic acids with amines, Synthetic Route of 18437-58-6, the publication is Yakugaku Zasshi (1961), 1146-50, database is CAplus.

4-Pyridinesulfonic acid, 4-HO₃SC₅H₄N, (I) (1.6 g.) in 16 ml. 28% NH₄OH and a small amount of ZnCl₂ in an autoclave heated 2 hrs. at 150-60° cooled, 10 ml. 2N NaOH added, the NH₄OH removed and the product extracted with CHCl₃ gave 0.65 g. 4H₂NC₅H₄N, m. 157-8°. 2,4-Me(HO₃S)C₅H₃N (3 g.), 30 ml. 28% NH₄OH and a small amount ZnCl₂ in an autoclave heated 24 hrs. at 150-60° and the product treated as above gave 1.21 g. 2,4-Me(H₂N)C₅H₃N, m. 94-5°. Similarly prepared were the following amino compounds (product, % yield, and m.p. given): 3,4-Me(H₂N)C₅H₃N, 57.2, 107.5-9.0°; 2,6,4-Me₂(H₂N)C₅H₂N, 70.8, 192-3°; [from 4-HO₃SC₉H₆N (II)] 4-H₂NC₉H₆N, 79.5, 153°. I (1.6 g.), 10 ml. 33% MeNH₂ and a small amount of ZnCl₂ heated 24 hrs. at 130° gave 0.87 g. 4-MeNHC₅H₄N; picrate, m. 122-4°. Similarly, I and Me₂NH yielded 72.5% 4-Me₂NC₅H₄N, m. 112-13° (picrate, m. 204°); II and MeNH₂ yielded 88.3% 4-MeNHC₉H₆N, m. 224°; II and Me₂NH yielded 76.3% 4-Me₂NC₉H₆N, b₁₀ 167° (picrate, m. 192°). 2-HO₃SC₅H₄N (1.6 g.), 3.2 ml. 80% N₂H₄.H₂O, 7 ml. H₂O, and a small amount of ZnCl₂ in an autoclave heated 24 hrs. at 100-5°, the solution filtered, the filtrate concentrated in vacuo, the residue in 10 ml. 50% KOH extracted with Et₂O, and the picrate formed gave 2.1 g. 2-H₂NNHC₅H₄N picrate, m. 162-3° (decomposition). Similarly prepared were the following hydrazine derivatives (starting material, product, % yield and m.p. or m.p. of its salt given): I, 4-H₂NNHC₅H₄N (III), 72, HCl salt, 242-4°; 2-HO₃SC₉H₆N, 2-H₂NNHC₉H₆N, 64.5, picrate, 187-9° (decomposition); II, 4-H₂NNHC₉H₆N (IV), 81.2, HCl salt, 3078°; 2,4-Me(HO₃S)C₉H₅N, 2,4-Me(H₂NNH)C₉H₅N, 73.3, picrate, 206° (decomposition). 4-H₂NNHC₉H₆N.HCl (0.5 g.) in 10 ml. H₂O, 2 ml. EtOH and 1 ml. 10% NaOH, while refluxing, treated dropwise with 15 ml. 10% CuSO₄, refluxed 1 hr., refluxed 1 hr. with 5 ml. 10% NaOH and the product steam distilled gave 0.25 g. C₉H₇N; picrate, m. 202-3°. III.HCl (1 g.) in 50 ml. absolute EtOH treated with EtONa (0.16 g. Na and 7 ml. EtOH), the NaCl removed, the solution concentrated to 10 ml., refluxed 1 hr. with 0.8 g. Et pyruvate and the product concentrated gave 1.05 g. Et pyruvate 4-pyridylhydrazone, columns, m. 128-30°. III.HCl (1.45 g.) in 40 ml. MeOH treated with 1 g. KSCN in 10 ml. MeOH, refluxed 9 hrs. and the product concentrated gave 1.4 g. III.HSCN, m. 1079°. III (from 1.6 g. III.HCl) in 10 ml. C₅H₅N at 0° treated dropwise with 1.55 g. BzCl, stirred 1 hr. at room temperature, kept overnight, the solvent removed, and the residue washed with H₂O gave 1.2 g. 4-pyridyldibenzoylhydrazine, m. 2345° (EtOH). III (from 1.45 g. III.HCl) in 10 ml. EtOH and 1 g. AcCH₂COMe refluxed 1 hr., the EtOH removed, the residue in 5 ml. 10% NaOH and 10 ml. H₂O extracted with CHCl₃ and the product distilled gave 1.15 g. 1-(4-pyridyl)3,5-dimethylpyrazole, b₅ 131-4°; picrate m. 237° (decomposition). A solution of 1.26 g. AcONa.3H₂O, 3 ml. H₂O, 1 g. IV.HCl, 0.37 g. Me₂CO and 1 ml. AcOH refluxed 1.5 hrs., cooled, 4 ml. H₂O added and the mixture made alk. with NH₄OH and kept overnight at 0° gave 0.62 g. acetone 4-quinolylhydrazone, m. 122°. IV (0.5 g.) in 5 ml. EtOH and 0.34 g. PhCHO refluxed 1 hr. and the product concentrated gave 0.46 g. benzaldehyde 4-quinolylhydrazone, m. 11314°. IV.HCl (0.9 g.) in 20 ml. H₂O, 0.63 g. AcONa.3H₂O and 0.4 g. pyruvic acid mixed well and the product filtered off gave 0.73 g. pyruvic acid 4-quinolylhydrazone, m. 246° (decomposition). IV (0.35 g.) in 4 ml. EtOH and 0.25 g. Et pyruvate refluxed 1 hr. and the solution concentrated gave 0.31 g. Et pyruvate 4-quinolylhydrazone, m. 178°. IV.HCl (1.4 g.), 0.7 g. KSCN, and 50 ml. MeOH refluxed 12 hrs. and the solution concentrated gave 1.2 g. IV.HSCN, m. 168-9°. IV (0.5 g.) in 5 ml. C₅-H₅N and 0.44 g. BzCl refluxed 3 hrs. and the product concentrated gave 0.37 g. 1-(4-quinolyl)-2-(benzoyl)hydrazine, m. 129.5-30.5°. IV (0.66 g.) in 5 ml. EtOH and 0.42 g. AcCH₂COMe refluxed 1 hr., the EtOH removed and the residue in 10% NaOH extracted with CHCl₃ gave 0.66 g. 1-(4quinolyl)-3,5-dimethylpyrrazole, b₄ 180-1°; picrate m. 198° (MeOH).

Yakugaku Zasshi published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C11H9ClN2O, Synthetic Route of 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Wu, De-Zhi published the artcileAn efficient method for the construction of 2-Aminothiazolo[5,4-c]pyridines via K₃[Fe(CN)₆] oxidized SP² C-H Functionalization, Computed Properties of 18437-58-6, the publication is Tetrahedron (2016), 72(52), 8610-8616, database is CAplus.

A practical approach to synthesize 2-aminothiazolo[5,4-c]pyridines from simple asym. pyridylthioureas was achieved by utilizing K₃[Fe(CN)₆] as the oxidant [e.g., I → II (97%)]. These reactions went through an intramol. oxidation and finally led to the formation of C-S bond. Furthermore, the possible oxidative cyclization mechanism was also explored by the addition of radical scavengers, which showed that the oxidative cyclization was promoted via a free radical mechanism.

Tetrahedron published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C7H16Cl2Si, Computed Properties of 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

He, Dian published the artcileDesign, Synthesis and Activity Evaluation of N-(pyridin-4-yl) Salicylamides as Antimycobacterial Agents, Computed Properties of 18437-58-6, the publication is Asian Journal of Chemistry (2014), 26(21), 7269-7275, 7 pp., database is CAplus.

A series of N-(pyridin-4-yl) salicylamides derivatives I (R¹ = H, Cl, CH₃; R² = R⁴ = H, Cl; R³ = H, Cl, CF₃; R⁵ = H, OCH₃; R⁶ = H, Cl, Br, CF₃) were prepared through acylation of the corresponding acetylsalicyloyl chlorides with substituted 4-aminopyridines. The compounds I were evaluated in vitro for antimycobacterial activities against Mycobacterium tuberculosis (TB) and Mycobacterium avium (A) by the min. inhibitory concentrations (MIC) values. Eight of the compounds I exhibited lower MIC against Mycobacterium avium than the one of isoniazide, meanwhile, four of the compounds I exhibited good anti-TB activity compared to isoniazide. Antimycobacterial activities of compounds I were influenced by the balance between hydrophobicity and electron withdrawing substituent effects on the Ph and pyridine ring.

Asian Journal of Chemistry published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H8N2, Computed Properties of 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Yang, Wenqing published the artcileDesign, Synthesis, Antifungal and Antibacterial Activities of N-phenyl and N-pyridinyl-5-(trifluoromethyl)-pyrazole-4-carboxamide Derivatives, Recommanded Product: 4-Amino-2-picoline, the publication is Journal of Heterocyclic Chemistry (2018), 55(10), 2261-2269, database is CAplus.

A series of N-Ph and N-pyridinyl-5-(trifluoromethyl)-pyrazole carboxamides, compounds I [R = Ph, 2-pyridinyl, 2-fluoro-4-pyridinyl, etc.] were designed and synthesized. Bioassay results indicated that antifungal and antibacterial activities of title compounds could be obviously improved by placing trifluoromethyl on the 5-position of the pyrazole ring and substituted 4-pyridinyl at the amine side of the amide bond. The EC₅₀ values of compound I [R = 4-pyridinyl] against Gibberella zeae, Cytospora mandshurica, and Fusarium oxysporum were 14.7, 21.1, and 32.7 μg/mL, resp., better than hymexazol (30.2, 47.3, and 42.5 μg/mL) and carboxin (34.2, >200, and >200 μg/mL). And the EC₅₀ values of compounds I [R = 2-fluoro-4-pyridinyl, 2,6-dichloro-4-pyridinyl, 3,5-dichloro-4-pyridinyl, 6-methyl-2-pyridinyl, 2-methylphenyl, 2-fluorophenyl, 4-chlorophenyl and 4-methoxyphenyl] against rice bacterial leaf blight were 17.0, 21.8, 21.9, 18.6, 16.8, 25.9, 9.4, and 24.4 μg/mL, resp., much better than bismerthiazol (70.5 μg/mL).

Journal of Heterocyclic Chemistry published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C9H21NO3, Recommanded Product: 4-Amino-2-picoline.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Okuda, Shigenobu published the artcileThe constitution of matrine. XXVI. The constitution of dehydro-α-matrinidine, Safety of 4-Amino-2-picoline, the publication is Pharmaceutical Bulletin (1956), 257-61, database is CAplus.

cf. C.A. 49, 8316f. The decision between the 2 proposed structures of dehydro-α-matrinidine (I), upon which the structure of matrine depends, is based on spectrographic comparisons. Ultraviolet absorption maximum are recorded for: the degradation products of matrine, I, and the 2 bases C₁₂H₁₈N₂, m. 111° and 190°, resp.; the 4-aminopyridine group of 4-H₂N and 4-Et₂N derivatives of C₅H₅N, and 5,7-dimethyl-1,2,3,4-tetrahydro-1,6-naphthyridine (II); the 3-aminopyridine group of 3-H₂N (III) and 3-Me₂N (IV) derivatives of C₅H₅N, and 2,4-dimethyl-5,6,7,8-tetrahydro-1,5-naphthyridine (V); the 2-aminopyridine group of the 2-H₂N derivative of C₅H₅N, and 2,4-dimethyl-5,6,7,8-tetrahydro-1,8-naphthyridine. The solvents used were EtOH, 0.1N NaOH, 0.01N H₂SO₄, 50% H₂SO₄, and concentrated H₂SO₄. The spectra of 2,4-Me(H₂N) and 2,6,4-Me₂(H₂N) derivatives of C₅H₅N were determined in EtOH only. Only II and IV were previously unknown. The synthesis of II will be reported later. Methylation of III with H₂CO and HCO₂H gave IV, b₆ 95°; picrate, m. 179-81°. Study of the spectra led to the following generalizations: the 3-aminopyridine group form their di-salts even in 50% H₂SO₂, whereas the matrine products and the 4-aminopyridine group show the same absorption in 50% as in 0.01N H₃SO₃; I absorbs at much shorter wave lengths than III in EtOH, 0.1N NaOH, and 0.01N H₂SO₂; C₂H₂N₂ both have the same absorption in all solvents, very similar to that of II, and very different from that of V. It is concluded that all 3 matrine degradation compounds have the 4-aminopyridine skeleton, that I is 1-methyl-4,5,6,8,9,10-hexahydropyrido[3,4,5-ij]quinolizine, and that the C₁₂H₁₈N₂ are Me derivatives of 8-propyl-1,2,3,4-tetrahydro-1,6-naphthyridine.

Pharmaceutical Bulletin published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H8N2, Safety of 4-Amino-2-picoline.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Profft, Elmar published the artcilePreparation and pharmacological properties of 1-(4-alkoxy-2-pyridyl)-2-ethylpiperidines, SDS of cas: 18437-58-6, the publication is Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft (1958), 429-36, database is CAplus.

The title compounds in which the alkoxy group was MeO, EtO, PrO, BuO, iso-BuO, AmO, iso-AmO, n-C₆H₁₃O, or n-C₇H₁₅O were prepared and tested for their activity as local anesthetics by surface application of a 1% solution of their HCl salts. The PrO compound was prepared by treating 24 g. 2,4-Me(PrO)C₅H₃N with 12 g. 40% HCHO and 3 drops of HOAc at 190° for 8 h. and working up with Et₂O to give 7 g. 2,4-HOCH₂CH₂(PrO)C₅H₃N (I), yellow oil, b₁₈ 182-6°. I (10 g.) kept with 2 g. KOH for 40 h., some hydroquinone added, and the product vacuum distilled gave 2,4-CH₂:CH(PrO)C₅H₃N (II), b₂₀ 125-7°. II (0.05 mol) heated with 0.033 mol piperidine and 0.0043 mol HOAc for 3 h. on a water bath at 95-110°, then vacuum distilled gave 1-(4-propoxy-2-pyridyl)-2-ethylpiperidine, a golden oil, b₁₆ 200.5°. The other members of the series were prepared in a similar manner. Only the n-C₆H₁₃O and n-C₇H₁₅O analogs showed any significant pharmacol. activity as local anesthetics. Quaternary iodides were also prepared from the 4-alkoxy-2-methylpyridines where the alkoxy group was MeO, EtO, PrO, BuO, or AmO by treatment of 0.02 mol of the picoline with 0.021 mol MeI in 3-5 mL. EtOH for 3 h.

Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H8N2, SDS of cas: 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Suzuki, Yasuyuki published the artcileReactions of 4-pyridine- and 4-quinolinesulfonic acids with amines, Synthetic Route of 18437-58-6, the publication is Yakugaku Zasshi (1961), 1146-50, database is CAplus.

4-Pyridinesulfonic acid, 4-HO₃SC₅H₄N, (I) (1.6 g.) in 16 ml. 28% NH₄OH and a small amount of ZnCl₂ in an autoclave heated 2 hrs. at 150-60° cooled, 10 ml. 2N NaOH added, the NH₄OH removed and the product extracted with CHCl₃ gave 0.65 g. 4H₂NC₅H₄N, m. 157-8°. 2,4-Me(HO₃S)C₅H₃N (3 g.), 30 ml. 28% NH₄OH and a small amount ZnCl₂ in an autoclave heated 24 hrs. at 150-60° and the product treated as above gave 1.21 g. 2,4-Me(H₂N)C₅H₃N, m. 94-5°. Similarly prepared were the following amino compounds (product, % yield, and m.p. given): 3,4-Me(H₂N)C₅H₃N, 57.2, 107.5-9.0°; 2,6,4-Me₂(H₂N)C₅H₂N, 70.8, 192-3°; [from 4-HO₃SC₉H₆N (II)] 4-H₂NC₉H₆N, 79.5, 153°. I (1.6 g.), 10 ml. 33% MeNH₂ and a small amount of ZnCl₂ heated 24 hrs. at 130° gave 0.87 g. 4-MeNHC₅H₄N; picrate, m. 122-4°. Similarly, I and Me₂NH yielded 72.5% 4-Me₂NC₅H₄N, m. 112-13° (picrate, m. 204°); II and MeNH₂ yielded 88.3% 4-MeNHC₉H₆N, m. 224°; II and Me₂NH yielded 76.3% 4-Me₂NC₉H₆N, b₁₀ 167° (picrate, m. 192°). 2-HO₃SC₅H₄N (1.6 g.), 3.2 ml. 80% N₂H₄.H₂O, 7 ml. H₂O, and a small amount of ZnCl₂ in an autoclave heated 24 hrs. at 100-5°, the solution filtered, the filtrate concentrated in vacuo, the residue in 10 ml. 50% KOH extracted with Et₂O, and the picrate formed gave 2.1 g. 2-H₂NNHC₅H₄N picrate, m. 162-3° (decomposition). Similarly prepared were the following hydrazine derivatives (starting material, product, % yield and m.p. or m.p. of its salt given): I, 4-H₂NNHC₅H₄N (III), 72, HCl salt, 242-4°; 2-HO₃SC₉H₆N, 2-H₂NNHC₉H₆N, 64.5, picrate, 187-9° (decomposition); II, 4-H₂NNHC₉H₆N (IV), 81.2, HCl salt, 3078°; 2,4-Me(HO₃S)C₉H₅N, 2,4-Me(H₂NNH)C₉H₅N, 73.3, picrate, 206° (decomposition). 4-H₂NNHC₉H₆N.HCl (0.5 g.) in 10 ml. H₂O, 2 ml. EtOH and 1 ml. 10% NaOH, while refluxing, treated dropwise with 15 ml. 10% CuSO₄, refluxed 1 hr., refluxed 1 hr. with 5 ml. 10% NaOH and the product steam distilled gave 0.25 g. C₉H₇N; picrate, m. 202-3°. III.HCl (1 g.) in 50 ml. absolute EtOH treated with EtONa (0.16 g. Na and 7 ml. EtOH), the NaCl removed, the solution concentrated to 10 ml., refluxed 1 hr. with 0.8 g. Et pyruvate and the product concentrated gave 1.05 g. Et pyruvate 4-pyridylhydrazone, columns, m. 128-30°. III.HCl (1.45 g.) in 40 ml. MeOH treated with 1 g. KSCN in 10 ml. MeOH, refluxed 9 hrs. and the product concentrated gave 1.4 g. III.HSCN, m. 1079°. III (from 1.6 g. III.HCl) in 10 ml. C₅H₅N at 0° treated dropwise with 1.55 g. BzCl, stirred 1 hr. at room temperature, kept overnight, the solvent removed, and the residue washed with H₂O gave 1.2 g. 4-pyridyldibenzoylhydrazine, m. 2345° (EtOH). III (from 1.45 g. III.HCl) in 10 ml. EtOH and 1 g. AcCH₂COMe refluxed 1 hr., the EtOH removed, the residue in 5 ml. 10% NaOH and 10 ml. H₂O extracted with CHCl₃ and the product distilled gave 1.15 g. 1-(4-pyridyl)3,5-dimethylpyrazole, b₅ 131-4°; picrate m. 237° (decomposition). A solution of 1.26 g. AcONa.3H₂O, 3 ml. H₂O, 1 g. IV.HCl, 0.37 g. Me₂CO and 1 ml. AcOH refluxed 1.5 hrs., cooled, 4 ml. H₂O added and the mixture made alk. with NH₄OH and kept overnight at 0° gave 0.62 g. acetone 4-quinolylhydrazone, m. 122°. IV (0.5 g.) in 5 ml. EtOH and 0.34 g. PhCHO refluxed 1 hr. and the product concentrated gave 0.46 g. benzaldehyde 4-quinolylhydrazone, m. 11314°. IV.HCl (0.9 g.) in 20 ml. H₂O, 0.63 g. AcONa.3H₂O and 0.4 g. pyruvic acid mixed well and the product filtered off gave 0.73 g. pyruvic acid 4-quinolylhydrazone, m. 246° (decomposition). IV (0.35 g.) in 4 ml. EtOH and 0.25 g. Et pyruvate refluxed 1 hr. and the solution concentrated gave 0.31 g. Et pyruvate 4-quinolylhydrazone, m. 178°. IV.HCl (1.4 g.), 0.7 g. KSCN, and 50 ml. MeOH refluxed 12 hrs. and the solution concentrated gave 1.2 g. IV.HSCN, m. 168-9°. IV (0.5 g.) in 5 ml. C₅-H₅N and 0.44 g. BzCl refluxed 3 hrs. and the product concentrated gave 0.37 g. 1-(4-quinolyl)-2-(benzoyl)hydrazine, m. 129.5-30.5°. IV (0.66 g.) in 5 ml. EtOH and 0.42 g. AcCH₂COMe refluxed 1 hr., the EtOH removed and the residue in 10% NaOH extracted with CHCl₃ gave 0.66 g. 1-(4quinolyl)-3,5-dimethylpyrrazole, b₄ 180-1°; picrate m. 198° (MeOH).

Yakugaku Zasshi published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C11H9ClN2O, Synthetic Route of 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Wu, De-Zhi published the artcileAn efficient method for the construction of 2-Aminothiazolo[5,4-c]pyridines via K₃[Fe(CN)₆] oxidized SP² C-H Functionalization, Computed Properties of 18437-58-6, the publication is Tetrahedron (2016), 72(52), 8610-8616, database is CAplus.

A practical approach to synthesize 2-aminothiazolo[5,4-c]pyridines from simple asym. pyridylthioureas was achieved by utilizing K₃[Fe(CN)₆] as the oxidant [e.g., I → II (97%)]. These reactions went through an intramol. oxidation and finally led to the formation of C-S bond. Furthermore, the possible oxidative cyclization mechanism was also explored by the addition of radical scavengers, which showed that the oxidative cyclization was promoted via a free radical mechanism.

Tetrahedron published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C7H16Cl2Si, Computed Properties of 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem