Day: December 1, 2022

Ueda, Kanichi published the artcilePyridine derivatives containing sulfur. L. Mechanism of cleavage of thiazole ring of 2-aminothiazolo[5,4-b]pyridines by means of aqueous alkali, Application In Synthesis of 31784-71-1, the publication is Pharmaceutical Bulletin (1956), 396-401, database is CAplus and MEDLINE.

cf. C.A. 51, 2741i. Determination of the structures of the previously reported (C.A. 48, 5187h) “Substances I (I), II (II), and III (III),” prepared from 6-Cl (IV) and 6-EtO (V) derivatives of 3-amino-2-mercaptopyridine should help clarify the mechanism of the cleavage of the thiazole ring of the title compounds Comparisons of the infrared and ultraviolet absorption spectra of I with those of the 3-amino (VI) and 3-acetamido (VII) derivatives of 6,2-Cl(MeS)C₅H₂N (VIII) led to the conclusion that I was 6,2,3-Cl(MeS)(H₂NCONH)C₅H₂N. This conclusion was supported by heating 0.6 g. I 6 hrs. on a H₂O bath with 40 cc. Ac₂O and evaporating in vacuo to give 0.08 g. 3-AcNHCONH derivative of VIII, m. 209°, and 0.3 g. VII, m. 166° (from the mother liquor chromatographed in CHCl₃ over Al₂O₃). Support also came from the synthesis of I:1.2 g. IV in 170 cc. AcOH treated slowly with 2.5 g. KNCO in 20 cc. H₂O at 40°, stirred 3 hrs., diluted with much H₂O, and kept overnight yielded 0.82 g. 6,2,3-Cl(HS)(H₂NCONH)C₅H₂N (IX), m. 185-90° (effervescence); this gave I, m. 286-95°, methylated with MeI in alk. solution Also, 0.8 g. VI similarly treated with KNCO yielded 0.8 g. I. Likewise treated with KNCO, 2-MeS (X) and 2-EtS derivatives of 3,6-H₂N(EtO)C₅H₃N gave II, m. 200-36°, and III, m. 160-1°, resp.; their ultraviolet spectra confirmed their structures as 6,2,3-EtO(MeS)(H₂NCONH)C₅H₂N and 6,2,3-EtO(EtS)(H₂NCONH)C₅H₂N, resp. The mechanism of cleavage of the thiazole ring in the 5-Cl (XI) and 5-EtO (XII) derivatives of the title compound was studied. XI (0.7 g.) was refluxed 1 hr. in an oil bath at 120-30° with 6 cc. 10% NaOH while NH₃ evolved, the solution neutralized with AcOH, the resulting precipitate methylated with Me₂SO₄, the ether extract of the product evaporated, and the residue fractionally crystallized to give 0.21 g. VI, m. 56° (from petr. ether-ether), and 0.22 g. I, m. 290° (from MeOH). However, refluxing 7 hrs. instead of 1 hr. gave only VI. IX (0.7 g.) similarly hydrolyzed for 1 hr. and methylated yielded 0.15 g. VI and 0.12 g. I, but after 6 hrs. hydrolysis it gave only VI. XII (1 g.) refluxed 6.5 hrs. with 10 cc. 20% NaOH in the presence of 0.2 g. As₂O₃ while NH₃ evolved, the mixture cooled, filtered, and the filtrate neutralized with AcOH yielded 0.7 g. V, m. 150-70° (characterized by methylation to X and acetylation to 3,6,2-AcNH(EtO)(MeS)C₅H₂N, m. 124°), and after standing overnight, 0.1 g. 6,2,3-EtO(HS)(H₂NCONH)C₅H₂N, m. 195-8° (decomposition)(characterized by methylation with Me₂SO₄ to II). Longer hydrolysis (10 hrs.) of XII gave only V. Confirmation of the production of V from XII was obtained by condensing it (0.5 g.) in 1 cc. H₂O and 5 cc. EtOH containing 0.2 g. NaOH with 0.6 g. BzCH₂Br to yield, after standing overnight at room temperature, the expected 6-ethoxy-2-phenylpyrido[2,3-b]1,4-thiazine(0.42 g.), m. 125° (C.A. 50, 10101g). These results of hydrolysis of IX, XI, and XII led to the conclusion that amino-thiazolopyridines were converted to mercaptopyridines through mercaptopyridylureas as intermediates, which were somewhat resistant to the hydrolysis.

Pharmaceutical Bulletin published new progress about 31784-71-1. 31784-71-1 belongs to thiazole, auxiliary class Other Aromatic Heterocyclic,Chloride,Amine, name is 5-Chlorothiazolo[5,4-b]pyridin-2-amine, and the molecular formula is C11H10ClNO, Application In Synthesis of 31784-71-1.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Sekar, N. published the artcileThiazole – containing monoazo direct dyes, Formula: C14H12N2S, the publication is Colourage (2005), 52(3), 95-98, database is CAplus.

A review. Chem. of monoazo direct dyes based on dehydrothio-p-toluidine and its higher analogs and the others containing thiazolyl residue is discussed in the light of structures documented in color index.

Colourage published new progress about 92-36-4. 92-36-4 belongs to thiazole, auxiliary class Organic Pigment, name is 2-(4-Aminophenyl)-6-methylbenzothiazole, and the molecular formula is C8H5F3O2S, Formula: C14H12N2S.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Riesz, E. published the artcileSome new benzothiazole derivatives and comparison dyeing with such compounds, Safety of 2-(4-Aminophenyl)-6-methylbenzothiazole, the publication is Textilveredlung (1991), 26(12), 403-5, database is CAplus.

The yellow dye primuline, prepared by heating p-toluidine with S, was separated into 3 bases, having the structure I (x = 0, 1, or 2), which were then converted into the corresponding Na sulfonate salts and used to dye viscose and cotton fabrics. For the I (x = 0) Na sulfonate, the fibers remained practically undyed, displaying only a light yellow tinge; with the sulfonates of I (x = 2) and I (x = 3) yellow and deep yellow dyeings were produced, resp. To evaluate the shade-deepening and affinity effects of the benzothiazole (II) groups, the 3 Na sulfonates were diazotized and coupled with β-naphthol on the fibers. Most of the dye was taken up by the fibers because of an increase in affinity, but a certain contribution by the shade-deepening effect of the II groups could not be excluded. Reaction of the 3 sulfonates with p-dimethylaminobenzaldehyde produced dyes containing a weaker chromophore, i.e., azomethine, than the azo group. These compounds dyed cellulosic fibers widely different shades of yellow and orange and, as free bases, gave basic dyes which dyed fibers from an HOAc solution without pretreatment. Conversion of the amino groups of the 3 bases into SH groups yielded the 1st purely synthetic S dyes for dyeing cellulosic fibers yellow shades.

Textilveredlung published new progress about 92-36-4. 92-36-4 belongs to thiazole, auxiliary class Organic Pigment, name is 2-(4-Aminophenyl)-6-methylbenzothiazole, and the molecular formula is C14H12N2S, Safety of 2-(4-Aminophenyl)-6-methylbenzothiazole.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Okamiya, Jiro published the artcile2-Amino-4(or 5)-arylthiazoles. II. Ultraviolet absorption spectra of α-naphthyl, biphenyl, and hydroxyaryl substituted compounds, Application In Synthesis of 56503-96-9, the publication is Nippon Kagaku Zasshi (1959), 903-6, database is CAplus.

cf. CA 55, 4486c. Ultraviolet absorption spectra of 2-amino-4(α-naphthyl)thiazole, m. 162°, 2-amino-4-(α-naphthyl)-5-methylthiazole, m. 195°, 2-amino-5-(α-naphthyl)thiazole, m. 129°, 2-amino-4-methyl-5-(α-naphthyl)thiazole, m. 163°, 2-amino-4-(α-naphthyl)-5-phenylthiazole, m. 223°, 2-amino-4-phenyl-5-(α-naphthyl)thiazole, m. 248°, 2-amino-4,5-bis(α-naphthyl)thiazole, m. 260° (decomposition), 2-amino-4-biphenylylthiazole, 2-amino-4-biphenylyl-5-phenylthiazole, m. 201°, 2-amino-4-(p-hydroxyphenyl)thiazole, m. 212°, 2-amino-4-(p-hydroxyphenyl)-5-methylthiazole-HCl, HCl, 208-10°, 2-amino-4-(o-hydroxyphenyl)thiazole, 2-amino-4-(o-hydroxyphenyl)-5-methylthiazole, m. 120°, 2-amino-4-(p-hydroxyphenyl)-5-phenylthiazole, m. 284°, 2-amino-4-(o-hydroxyphenyl)-5-phenylthiazole, m. 171°, and 2-amino-4-(2-hydroxy-1-naphthyl)thiazole, m. 198°, were reported. The naphthyl group, due to its steric hindrance, exerted less effect on spectra, but was bathochromic at 5 position when compared with that at 4 position. The o-hydroxyphenyl group gave a red shift to the maximum at shorter wave length in spite of its expected steric effects. This must be attributed to the existence of chelation. Intermediate ketones of above thiazoles were prepared α-Bromonaphthalene (27.6 g.) was converted to Grignard reagent, 1.33 g. CdCl₂ added, the solvent replaced by C₆H₆, and 8.3 g. AcCl added to give 11 g. α-acetonaphthone. Similarly, α-propionaphthone, α-naphthyl benzyl ketone, ω-(α-naphthyl)acetophenone and ω-(α-naphthyl)acetonaphthone were prepared in 55, 60, 59 and 36% yields, resp. Naphthalene (100 g.), 250 cc. CS₂, and 130 g. AlCl₃ treated with ethylene oxide from 70 cc. ClCH₂CH₂OH gave 29 g. α-naphthylethanol which was oxidized with CrO₃ in AcOH to α-naphthylacetaldehyde. EtOMgCH(CO₂Et)₂ prepared from 9 g. CH₂(CO₂Et)₂, 1.3 g. Mg, and 7 cc. EtOH was treated with α-naphthylacetyl chloride prepared from 9.5 g. α-naphthylacetic acid and SOCl₂, and the product hydrolyzed to give 5 g. α-naphthylacetone.

Nippon Kagaku Zasshi published new progress about 56503-96-9. 56503-96-9 belongs to thiazole, auxiliary class Thiazole,Amine,Naphthalene, name is 4-(Naphthalen-1-yl)thiazol-2-amine, and the molecular formula is C13H10N2S, Application In Synthesis of 56503-96-9.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Okafor, Charles O. published the artcileHeterocyclic series. VII. Use of Kaufmann’s reaction as a route to o-aminomercaptopyridines, COA of Formula: C6H4ClN3S, the publication is Journal of Organic Chemistry (1973), 38(26), 4383, database is CAplus.

Kaufmann thiocyanation of 6-substituted 2-amino- and 3-aminopyridines gave 6-substituted-2-amino-3-thiocyanatopyridine (I) and 5-substituted-2-aminothiazolo[5,4-b]pyridine (II), resp. The action of 20% NaOH on II led to 6-substituted 3-aminopyridine-2(1H)-thiones. Heating I in Ac2O gave 5-substituted 2-acetamidothiazolo[4,5-b]pyridine.

Journal of Organic Chemistry published new progress about 31784-71-1. 31784-71-1 belongs to thiazole, auxiliary class Other Aromatic Heterocyclic,Chloride,Amine, name is 5-Chlorothiazolo[5,4-b]pyridin-2-amine, and the molecular formula is C6H4ClN3S, COA of Formula: C6H4ClN3S.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Okafor, Charles O. published the artcileHeterocyclic series. II. 3,6-Diazaphenothiazine sulfoxides and other potential antiparasitic and pesticidal agents, Application In Synthesis of 31784-71-1, the publication is Journal of Chemical and Engineering Data (1971), 16(2), 244-6, database is CAplus.

New derivatives of thiazolo[5,4-b]pyridine (I) and 3,6-diazaphenothiazine (II) are described. The yields of products spotlight a definite trend in the role of substituents in the conversion of pyridine derivatives to thiazolo[5,4-b]pyridines. Some derivatives of these compounds were hydrolyzed and converted to nitrothienyl pyridyl sulfides of antibacterial and pesticidal interests by reacting with 2-bromo-3,5-dinitrothiophene. The latter similarly reacts with aminopyridines to yield thienyl aminopyridines. In an attempt to convert 7-methoxy- and 7-chloro-1-nitro-3,6-diazaphenothiazines to their dinitro-3,6-diazaphenothiazine derivatives, only 7-methoxy- and 7-chloro-1-nitro-3,6-diazaphenothiazine sulfoxides, identified by their strong sulfoxide band in the 1035-to 1045-cm-1 region, were obtained.

Journal of Chemical and Engineering Data published new progress about 31784-71-1. 31784-71-1 belongs to thiazole, auxiliary class Other Aromatic Heterocyclic,Chloride,Amine, name is 5-Chlorothiazolo[5,4-b]pyridin-2-amine, and the molecular formula is C6H4ClN3S, Application In Synthesis of 31784-71-1.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Okafor, Charles O. published the artcileThe first branched benzoxazinophenothiazine ring system and its aza analogs, Application of 5-Chlorothiazolo[5,4-b]pyridin-2-amine, the publication is Tetrahedron (1988), 44(4), 1187-94, database is CAplus.

The synthesis of a branched benzoxazinophenothiazine heterocycle is described. The parent compound benzo[a][1,4]-benzoxazino[3,2-c]phenothiazine (I), was obtained from 2,3-dichloro-1,4-naphthoquinone, 2-aminophenol and 2-(amino)thiophenol. Monoaza-, diaza- and triaza- analogs of this novel heterocycle were also synthesized. The parent compounds, 16-oxa-15-thia-4,5,10-triazabenzo[h]pentaphene and 16-oxa-15-thia-4,5,10,14-tetraazabenzo[h]pentaphene were also synthesized as well as 4-amino-16-oxa-15-thia-4,5,10,12,14-pentaazabenzo[h]pentaphene. They are intensely colored high-melting solids suitable for application as pigments. Their ease of reduction with Na₂S₂O₄ and the ready oxidation of the reduced compounds to the quinoid forms by atm. oxygen suggest their applicability also as vat dyes.

Tetrahedron published new progress about 31784-71-1. 31784-71-1 belongs to thiazole, auxiliary class Other Aromatic Heterocyclic,Chloride,Amine, name is 5-Chlorothiazolo[5,4-b]pyridin-2-amine, and the molecular formula is C6H4ClN3S, Application of 5-Chlorothiazolo[5,4-b]pyridin-2-amine.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Mahapatra, G. N. published the artcileBromination of 2-aminothiazoles and their use as possible fungicides and bactericides, Product Details of C13H10N2S, the publication is Journal of the Indian Chemical Society (1956), 527-31, database is CAplus.

Seventeen 4-aryl-2-aminothiazoles (I) were prepared and brominated to 5-bromo-4-aryl-2-aminothiazoles (II). The aryl group and the m.ps., resp., are : Ph, 153-4°, 103°; p-MeC₆H₄, 123-4°, 106°; p-EtC₆H₄, 107-8°, 112°; 3,4-Me₂C₆H₃, 135-6°, 107°; 2,5-Me₂C₆H₃, 177-8°, 187°; p-MeOC₆H₄, 204-5°, 152°; p-EtOC₆H₄, 230-1°, 98°; ο-HOC₆H₄, 139-40°, 221°; p-HOC₆H₄, 198-9°, 235°; p-BrC₆H₄, 176-7°, 192°; m-H₂NC₆H₄, 170-1°, 207°; p-H₂NC₆H₄, 174-5°, 200°; α-C₁₀H₇, 130-1°, 111°; β-C₁₀H₇, 150-1°, 168°; 2-thienyl, 107-8°, 217°; PhCH₂CH₂, 90-1°, 201°; and MeOC₆H₄CH₂CH₂, 97-8°, 197° (decomposition). The bactericidal activity was determined in terms of the maximum effective dilution (M. E.D.) at 10 min. exposure. The M.E.D. for Escherichia coli was 1:1000 (maximum) for I and 1:1000 to 1:4000 for II; for Staphylococcus aureus was 1:8000 (maximum) for I and 1:10,000 to 1:20,000 for II. The fungicidal activity against Alternaria brassicae was: II at 50 p.p.m. and I at 80 p.p.m. inhibited spore germination; II at 40 p.p.m. reduced spore germination to 15-20%.

Journal of the Indian Chemical Society published new progress about 56503-96-9. 56503-96-9 belongs to thiazole, auxiliary class Thiazole,Amine,Naphthalene, name is 4-(Naphthalen-1-yl)thiazol-2-amine, and the molecular formula is C13H10N2S, Product Details of C13H10N2S.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Law, K. P. published the artcileSurface-assisted laser desorption/ionization mass spectrometry on nanostructured silicon substrates prepared by iodine-assisted etching, Recommanded Product: 2-(4-Aminophenyl)-6-methylbenzothiazole, the publication is International Journal of Mass Spectrometry (2010), 290(1), 47-59, database is CAplus.

Surface-assisted laser desorption/ionization (SALDI) is a matrix-free mass spectrometry (MS) approach that utilizes the unique properties of a nanostructured surface to promote desorption and ionization. However, there are still questions on what constitutes a suitable SALDI substrate for mass spectrometric application. A range of SALDI substrates prepared by anodization with an oxidizing electrolyte was investigated. The laser desorption/ionization (LDI) performance was examined on a reflectron time-of-flight (ToF) mass spectrometer. The physicochem. properties of the substrates were characterized by a number of surface anal. techniques including SEM, at. force microscopy (AFM), secondary ion mass spectrometry (SIMS), XPS and water contact angle measurement. Examination of surface cleaning technologies and methods for surface chem. modification were carried out. Correlation between the substrate physicochem. properties and the LDI performance was determined It was found that only the substrate, which had a thick nanostructured layer, was effective for LDI-MS. SALDI substrate was found to have a high surface potential. However, this unique property offered no advantage for the application of LDI-MS. Surface chem. is also an important factor in affecting the LDI performance. Plasma etching can effectively remove the surface contamination but it also increases the thickness of the oxide layer. Fluorine and hydroxyl termination is advantageous. Fluorine passivation increases the surface hydrophobicity, which confines the analyte solution droplet to a smaller area and also withdraws the electronic d. from the surface, and acidifies the surface Si-OH moieties, which is believed a major proton source. The effect of laser etching was investigated by SIMS and XPS imaging and provided new insight of the SALDI ionization mechanism.

International Journal of Mass Spectrometry published new progress about 92-36-4. 92-36-4 belongs to thiazole, auxiliary class Organic Pigment, name is 2-(4-Aminophenyl)-6-methylbenzothiazole, and the molecular formula is C14H12N2S, Recommanded Product: 2-(4-Aminophenyl)-6-methylbenzothiazole.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica

Haroun, Michelyne published the artcileIn Silico Design, Synthesis and Evaluation of Novel Series of Benzothiazole- Based Pyrazolidinediones as Potent Hypoglycemic Agents, Formula: C7H5ClN2S, the publication is Medicinal Chemistry (Sharjah, United Arab Emirates) (2020), 16(6), 812-825, database is CAplus and MEDLINE.

The discovery of novel ligand binding domain (LBD) of peroxisome proliferator- activated receptor γ (PPARγ) has recently attracted attention to few research groups in order to develop more potent and safer antidiabetic agents. This study is focused on docking-based design and synthesis of novel compounds combining benzothiazole and pyrazolidinedione scaffold as potential antidiabetic agents. Several benzothiazole-pyrazolidinedione hybrids were synthesized and tested for their in vivo anti-hyperglycemic activity. Interactions profile of title compounds against PPARγ was examined through mol. modeling approach. All tested compounds exhibited anti-hyperglycemic activity similar or superior to the reference drug Rosiglitazone. Introducing chlorine atom and alkyl group at position-6 and -5 resp. on benzothiazole core resulted in enhancing the anti-hyperglycemic effect. Docking study revealed that such groups demonstrated favorable hydrophobic interactions with novel LBD Ω – pocket of PPARγ protein. Among the tested compounds, N-(6-chloro-5-methylbenzo[d]thiazol-2-yl-4-(4((3,5- dioxopyrazolidin-4-ylidene)methyl)phenoxy)butanamide) 5b was found to be the most potent compound and provided valuable insights to further develop novel hybrids as anti-hyperglycemic agents.

Medicinal Chemistry (Sharjah, United Arab Emirates) published new progress about 95-24-9. 95-24-9 belongs to thiazole, auxiliary class Organic Pigment, name is 6-Chlorobenzothiazol-2-ylamine, and the molecular formula is C7H5ClN2S, Formula: C7H5ClN2S.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/thiazole,
Thiazole | chemical compound | Britannica