Tag: M.W=150-200

Wu, Bei published the artcileImproved synthesis of tizanidine hydrochloride, Category: thiazole, the publication is Zhongguo Xinyao Zazhi (2006), 15(8), 621-623, database is CAplus.

The synthetic way of tizanidine hydrochloride [i.e., 5-chloro-N-(4,5-dihydro-1H-imidazol-2-yl)-2,1,3-benzothiadiazol-4-amine hydrochloride] is reported. Tizanidine hydrochloride was synthesized using 4-chloro-2-nitroaniline as a starting material via several steps, including reduction with hydrazine/Fe-C, cyclization, nitration and reduction of nitro group with Fe/HOAc, condensation of 5-chloro-4-amino-2,1,3-benzothiadiazole with N-acetyl-2-imidazolidinone, alcoholysis and salt formation. The total yield of the target compound was 52.4%. The structure of the target compound was confirmed by IR, ¹H-NMR, ¹³C-NMR, MS and element anal. This improved synthetic procedure was mild and easily manipulated.

Zhongguo Xinyao Zazhi published new progress about 30536-19-7. 30536-19-7 belongs to thiazole, auxiliary class Other Aromatic Heterocyclic,Chloride,Amine, name is 5-Chlorobenzo[c][1,2,5]thiadiazol-4-amine, and the molecular formula is C2H4ClNO, Category: thiazole.

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

Xu, Jia published the artcileSynthesis of tizanidine hydrochloride, Product Details of C6H4ClN3S, the publication is Zhongguo Yiyao Gongye Zazhi (2005), 36(10), 593-595, database is CAplus.

Tizanidine hydrochloride [i.e., 5-chloro-N-(4,5-dihydro-1H-imidazol-2-yl)-2,1,3-benzothiadiazol-4-amine hydrochloride] was synthesized from 4-chloro-2-nitroaniline by reduction with Zn/NaOH, cyclization, nitration and reduction of nitro group with Fe/HOAc to afford 5-chloro-4-amino-2,1,3-benzothiadiazole which subsequently was subjected to condensation with 1-acetyl-2-imidazolidinone, hydrolysis and then HCl salt formation with an overall yield of 46%.

Zhongguo Yiyao Gongye Zazhi published new progress about 30536-19-7. 30536-19-7 belongs to thiazole, auxiliary class Other Aromatic Heterocyclic,Chloride,Amine, name is 5-Chlorobenzo[c][1,2,5]thiadiazol-4-amine, and the molecular formula is C10H15NO, Product Details of C6H4ClN3S.

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

Zhu, Yu-Shen published the artcileIodine-catalyzed amination of benzothiazoles with KSeCN in water to access primary 2-aminobenzothiazoles, Computed Properties of 95-24-9, the publication is Chinese Chemical Letters (2022), 33(3), 1497-1500, database is CAplus.

A facile and sustainable approach for the amination of benzothiazoles I (X = H, N; R = H, 4-Cl, 5-OMe, 6-NO₂, 7-C(O)OMe; R¹ = H) with KSeCN using iodine as the catalyst in water has been disclosed under transition-metal free conditions. The reaction proceeded smoothly to afford various primary 2-amino benzothiazoles I (R¹ = NH₂) in up to 96% yield. A series of control experiments were performed, suggesting that a ring-opening mechanism was involved via a radical process. This protocol provides efficient synthesis of primary 2-aminobenzothiazole I (R¹ = NH₂).

Chinese Chemical Letters 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 C8H5F3O3, Computed Properties of 95-24-9.

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

Nishad, Ravi K. published the artcileDesign and Synthesis of 2-Substituted Benzothiazole Derivatives as Antioxidant and Antimicrobial Agents, Computed Properties of 95-24-9, the publication is Current Bioactive Compounds (2020), 16(8), 1242-1248, database is CAplus.

An upsurge in the number of antibiotic-resistant microbial infections has warranted the discovery and development of new antibiotics. This is a matter of great concern for effective therapy for a search of novel antimicrobial agents. Literature has a number of reports of involvement of oxidative stress due to an imbalance between the generation and neutralization of free radicals in many diseases. Heterocyclic compounds have been involved in the treatment of various disorders. Benzothiazole is one such heterocyclic nucleus having benzene ring merged with the thiazole ring. Among the various substitutions possible in this nucleus, substitutions at position-2 have already been reported with potential bioactivities. Thus, different substituted compounds have been synthesized which could serve as antimicrobials and antioxidants. Benzothiazole derivatives (B₁-B₇) were synthesized by two-step reactions and the structures were confirmed through IR, mass and NMR spectroscopy. The compounds were evaluated for in vitro antioxidant and antimicrobial activities using standard methods. The results of antibacterial and antifungal activity showed that compound B₄ exhibited maximum activity against all the tested strains of microorganisms with the zone of inhibition 17.1-18.5 mm and MIC value 1.1-1.5μg/mL. Compound B₅ exhibited potent antioxidant activity. The compounds substituted with halogen on the aryl ring showed increased antimicrobial activity as seen in the case of compound B₄ (6-fluoro). The compounds substituted with a hydroxyl group (B₅) exhibited good antioxidant activity.

Current Bioactive Compounds 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, Computed Properties of 95-24-9.

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

Mor, Satbir published the artcileSynthesis, Type II diabetes inhibitory activity, antimicrobial evaluation and docking studies of indeno[1,2-c]pyrazol-4(1H)-ones, HPLC of Formula: 95-24-9, the publication is Medicinal Chemistry Research (2020), 29(1), 46-62, database is CAplus and MEDLINE.

A convenient and efficient synthesis of indeno[1,2-c]pyrazol-4(1H)-ones I (R¹ = Me, i-Pr, i-butyl; R² = H, Me, Cl, etc.) by the reaction of a variety of 2-acyl-(1H)-indene-1,3(2H)-diones and 2-hydrazinylbenzo[d]thiazole/2-hydrazinyl-6-substitutedbenzo[d]thiazoles in the presence of glacial acetic acid in good yields is reported. All the synthesized indeno[1,2-c]pyrazol-4(1H)-ones I were assayed for their in vitro Type II diabetes inhibitory activity by using Acarbose as standard drug and in vitro antimicrobial activity utilizing Streptomycin and Fluconazole as reference drugs. Among the synthesized derivatives, I (R¹ = Me; R² = Br) (IC₅₀ = 6.71 μg/mL) was found to be more potent against α-glucosidase enzyme as compared with the standard Acarbose (IC₅₀ = 9.35 μg/mL) and I (R¹ = i-propyl; R² = Cl) (IC₅₀ = 11.90 μg/mL) exhibited good inhibitory activity against α-amylase enzyme as compared with the standard Acarbose (IC₅₀ = 22.87 μg/mL). Also, all the titled compounds showed good antimicrobial activity. In addition, in vitro α-glucosidase and α-amylase inhibition were supported by docking studies performed on the derivatives I (R¹ = Me, i-butyl; R² = Br) resp.

Medicinal Chemistry Research 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, HPLC of Formula: 95-24-9.

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

Mor, Satbir published the artcileConvenient and efficient synthesis of novel 11H-benzo[5,6][1,4]thiazino[3,4-a]isoindol-11-ones derived from 2-bromo-(2/3-substituted phenyl)-1H-indene-1,3(2H)-diones, Product Details of C7H5ClN2S, the publication is RSC Advances (2019), 9(23), 12784-12792, database is CAplus and MEDLINE.

An unprecedented formation of 11H-benzo[5,6][1,4]thiazino[3,4-a]isoindol-11-ones I (R¹ = 2-Me, 2-MeO, 2-F, 3-F; R² = H, Me, OMe, Cl, Br) through a one-step reaction of differently substituted 2-aminobenzenethiols 2-H₂N-5-R²C₆H₄SH and 2-bromo-(2/3-substituted phenyl)-1H-indene-1,3(2H)-diones II in freshly dried ethanol under reflux conditions has been investigated. This unique transformation probably occurs through an initial nucleophilic substitution followed by ring opening and subsequent intramol. cyclization. The structures of all the synthesized benzo[1,4]thiazino isoindolinones I were established by FTIR, ¹H NMR, ¹³C NMR, HRMS, and X-ray crystallog. anal. This approach was found to be simple and convenient and provides several advantages such as substantial atom economy, short reaction time and operational simplicity.

RSC Advances 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, Product Details of C7H5ClN2S.

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

Adams, A. published the artcileThiazoles derived from chrysean and isochrysean, HPLC of Formula: 101012-16-2, the publication is Journal of the Chemical Society (1956), 1870-7, database is CAplus.

Throughout this abstract, R is the thiazole nucleus. A solution of 25 kg. NaCN in 57 l. H₂O and 1 l. aqueous NH₃ (d. 0.88) was circulated through a 5′ × 6″ Pyrex tower packed with 1” Raschig rings, and treated with 15-16 kg. H₂S over 6 hrs. The H₂O-washed product was dried at 100° and crystallized from a mixture of 25 l. H₂O, 3.15 l. HOAc and 100 g. C, giving 920 g. chrysean, 2,5-H₂NSCRNH₂ (I), m. 215-16° (after further crystallization from N HOAc). The mother liquor was adjusted to pH 6 with NH₃, concentrated, and the crude residue H₂O-washed, giving 20.7 g. isochrysean, 4,5-H₂NSCRNH₂ (II), m. 131-50°. Further treatment of the filtrates gave an addnl. 106.7 g. crude II. Passing a sample through an alumina column gave pure II, m. 155° (from EtOH). Treating 1 g. I in 4 cc. C₅H₅N with 0.55 g. AcCl at 0-5° gave 0.8 g. Ac derivative, m. 250° (decomposition) (yellow needles from 2N HOAc). Similarly, 2,5-NCRNH₂ (III) (cf. C.A. 38, 3628⁶) with BzCl gave the Bz derivative, m. 211-12° (from EtOH); this was hydrolyzed by boiling 3 hrs. with 20% aqueous NaOH and acidifying the cold solution, giving 2,5-HO₂CRNHBz, m. 159°. PhCl was slowly distilled during 1 hr. from a mixture of 1 g. III, 1.4 g. o-C₆H₄(CO)₂O (IV), and 20 cc. PhCl, fresh solvent being added as needed. The product was washed with PhCl and dried giving 5,2-o-HO₂CC₆H₄CONHRCN (V), m. 253° (pale yellow, from MeOH), also m. 210° (decomposition) when placed in a pre-heated bath. Boiling V 1 hr. with aqueous NaOH gave 5,2-o-HO₂CC₆H₄CONHRCO₂H (VI), m. 154° (decomposition) (from dilute aqueous HCl). Boiling 1 g. VI with 15 cc. HOAc for 1 hr. gave 0.5 g. 5-o-C₆H₄(CO)₂NR, m. 147° (from aqueous HOAc). Boiling 10 g. III and 16.5 g. powdered IV 6 hrs. in 150 cc. HOAc gave 18.4 g. 5,2-o-C₆H₄(CO)₂NRCN (VII), m. 255-6° (orange needles, from HOAc). A stirred suspension of 50 g. VII in 825 cc. dry CHCl₃ and 20 g. dry EtOH was saturated at 0-5° with dry HCl and kept at 0° for 5 days. The resulting precipitate and 2 l. H₂O were heated on a steam bath 1 hr., giving 5,2-o-C₆H₄(CO)₂NRCO₂Et (VIII), m. 171° (pale yellow needles, from naphtha, b. 80-100°, and EtOH alternately) and unchanged VII. Stirring 90 cc. 100% N₂H₄.H₂O into a suspension of 58 g. VIII in 850 cc. EtOH, filtering the solution, letting it stand overnight, removing the solid, dissolving it in 2N NaOH, acidifying the solution, removing the precipitate, neutralizing the filtrate and concentrating it, and combining the resulting solid with the solid obtained by concentrating the original reaction filtrate, gave a total of 20 g. 5,2-H₂NRCONHNH₂, m. 190° (from H₂O, then from EtOH). When only 2 moles of N₂H₄ were used instead of an excess, the product was 5,2-H₂NRCO₂Et, m. 118° (cream-colored needles, from H₂O). 5,2-o-C₆H₄(CO)₂NRCO₂Bu (IX), m. 167-9° (pale yellow needles, alternately from ligroine and EtOH) was prepared in 54% yield in the same manner as VIII and was converted to 5,2-H₂NRCO₂Bu, m. 81-2° (from 2N HOAc, 69% yield). Hydrolysis of 2,5-NCRNHAc with dry HCl in EtOH-CHCl₃ gave 2,5-EtO₂CRNHAc (X), m. 191-2° (from H₂O); similarly was prepared 2,5-MeO₂CRNHAc, m. 216-17° (82% yield). Heating X with 100% N₂H₄.H₂O in EtOH 15 min. at 100°, then letting the mixture stand overnight gave 2,5-H₂NHNOCRNHAc, m. 286° (decomposition) (from EtOH). Diazotizing III in the presence of freshly precipitated CuCl gave 2,5-NCRCl (XI), m. 50° (from naphtha, b. 60-80°), accompanied by 2,5-H₂NOCRCl (XII), m. 189-91° (from EtOH). XI was converted into XII, m. 193°, by hydrolysis with dry HCl in CHCl₃-EtOH. Boiling XI 1 hr. in 2N NaOH gave 2,5-HO₂CRCl (XIII), m. 111-12°, purified by dissolving the sample in 2N NaOH, clarifying with C, and repptg. the free acid with 2N HCl. Treatment of XIII with CH₂N₂ gave the Me ester, m. 53° (from naphtha, b. 40-60°), which upon treatment with N₂H₄.H₂O gave 2,5-H₂NHNOCRCl, m. 197° (from EtOH). Mixing 1 g. XI with 2 cc. N₂H₄.H₂O and letting the mixture stand 2 hrs. gave 1.12 g. 5,2-ClRC(:NH)NHNH₂, m. 148° (decomposition) (pale yellow needles from EtOH), resolidifying and remelting at about 220°. Refluxing 5,2-p-AcNHC₆H₄SO₂NHRCSNH₂ 1.25 hrs. with 2N NaOH gave 5,2-p-H₂NC₆H₄SO₂NHRCO₂H (XIV), m. 189° (decomposition) (yellow-white, from naphtha, b. 60-80°, and EtOH). XIV in boiling H₂O gave 5-p-H₂NC₆H₄SO₂NHR, which with cold, dry NaOMe in MeOH gave (5-p-H₂NC₆H₄SO₂NNaR).MeOH, decomposition by 200°. Reduction of 5,2-p-O₂NC₆H₄SO₂NHRCSNH₂ with ammoniacal FeSO₄ gave 5,2-p-H₂NC₆H₄SO₂NHRCSNH₂, m. 219-20° (golden needles, from HOAc). Isochrysean derivatives were prepared as follows: II with AcCl in dry C₅H₅N at 0-5° gave 4,5-H₂NSCRNHAc (XV), m. 208-10° (pale yellow needles, from 2N HOAc); XV was converted to 4,5-NCRNHAc (XVI), m. 202° (from N HOAc) either by boiling 0.75 hr. with aqueous Pb(OAc)₂, or by shaking XV overnight at room temperature with a concentrated aqueous solution of Pb(NO₃)₂ to which 10% aqueous NaOH had been added until the precipitate redissolved. Boiling XV 1.5 hrs. with 2N NaOH and acidifying the resulting solution at 0° with 2N HCl gave 1,6-dihydro-2-methyl-6-thiazolo[4′,5′:5,4]pyrimidine, m. 266° (yellow), soluble in aqueous NaHCO₃ but not in dilute acid. Warming an Me₂CO suspension of XVI 45 min. with 20% aqueous H₂O₂ and 2N Na₂CO₃, Me₂CO being added as required to prevent precipitation of solid, then letting the mixture stand 16 hrs., gave 4,5-H₂NOCRNHAc (XVII), m. 212-13° (from H₂O); ultraviolet absorption data are given. XVII was also prepared from 4,5-H₂NOCRNH₂ with AcCl in dry C₅H₅N at 0-5°. Refluxing 10 g. II, 12.5 g. VI and 150 cc. HOAc 2 hrs. and letting the mixture stand overnight gave 5,4-o-HO₂CC₆H₄CONHRCSNH₂ (XVIII), m. 243-4° (pale yellow needles, from HOAc); treatment of XVIII with alk. Pb(NO₃)₂ as described previously gave 5,4-o-HO₂CC₅H₄CONHRCN (XIX), m. 224° (decomposition), hydrolyzed by 2N NaOH to 5,4-o-HO₂CC₆H₄CONHRCONH₂, m. 203° (decomposition), a white powder, resolidifying to yellow rhombohedra, m. 345-50°. Boiling XIX 2 hrs. with Ac₂O gave 5,4-o-C₆H₄(CO)₂NRCN, m. 196° (from Ac₂O). A solution of 5,4-H₂NRCO₂Et in dry C₅H₅N was treated at 0° with p-AcNHC₆H₄SO₂Cl and the crude product hydrolyzed by boiling 2 hrs. with 2N NaOH, giving 5,4-p-H₂NC₆H₄SO₂NHRCO₂H, m. 184° (decomposition) on slow heating, but immediate decomposition in a bath at 160°; the compound was believed to be the hemihydrate.

Journal of the Chemical Society published new progress about 101012-16-2. 101012-16-2 belongs to thiazole, auxiliary class Thiazole,Chloride,Carboxylic acid, name is 5-Chlorothiazole-2-carboxylic acid, and the molecular formula is C4H2ClNO2S, HPLC of Formula: 101012-16-2.

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

Nazare, Marc published the artcileA flexible, palladium-catalyzed indole and azaindole synthesis by direct annulation of chloroanilines and chloroaminopyridines with ketones, Name: 5-Chlorobenzo[c][1,2,5]thiadiazol-4-amine, the publication is Angewandte Chemie, International Edition (2004), 43(34), 4526-4528, database is CAplus and MEDLINE.

The “ringmaster” [Pd(tBu₃P)₂] served as the catalyst in the direct synthesis of indoles, e.g., I, by annulation of ortho-chloroanilines with ketones. This versatile method can be used to synthesize a variety of functionalized indoles and azaindoles, e.g., II.

Angewandte Chemie, International Edition published new progress about 30536-19-7. 30536-19-7 belongs to thiazole, auxiliary class Other Aromatic Heterocyclic,Chloride,Amine, name is 5-Chlorobenzo[c][1,2,5]thiadiazol-4-amine, and the molecular formula is C6H4ClN3S, Name: 5-Chlorobenzo[c][1,2,5]thiadiazol-4-amine.

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

Stanetty, Peter published the artcileHalogenated 2′-Chlorobithiazoles via Pd-Catalyzed Cross-Coupling Reactions, Synthetic Route of 329794-40-3, the publication is Journal of Organic Chemistry (2006), 71(10), 3754-3761, database is CAplus and MEDLINE.

Halogenated bithiazoles allow facile further functionalization and are, therefore, suitable intermediates for the synthesis of compounds with interesting biol. activity or material science properties. The applicability of three coupling methods (Negishi, Suzuki, and Stille) for the synthesis of the title compounds was compared. The Negishi method proved to be troublesome, and side reactions were predominant. The synthesis of the first thiazoleboronic acid ester offered a new method for the formation of bithiazoles, not generally applicable so far. The lower toxicity compared to that of tin organyls make this method an approach with interesting perspectives. The Stille coupling proved to be superior to the other methods and enabled the synthesis of the title compounds with diverse connectivity.

Journal of Organic Chemistry published new progress about 329794-40-3. 329794-40-3 belongs to thiazole, auxiliary class Thiazole,Chloride,Benzene, name is 2-Chloro-5-phenylthiazole, and the molecular formula is C20H19NO4, Synthetic Route of 329794-40-3.

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

Campaigne, E. published the artcileReactions of 4-chloroacetoacetic esters with thioureas, Quality Control of 64987-16-2, the publication is Journal of Heterocyclic Chemistry (1980), 17(6), 1255-7, database is CAplus.

Thiazoles I (R = Me, Et) were prepared in 61 and 83% yields, resp., by cyclizing ClCH₂COCH₂CO₂R (II) with H₂NCSNH₂. Cyclizing II with III (n = 1, 2) gave 50-88% IV. Hydrolysis of IV (R = Et) gave IV (R = H).

Journal of Heterocyclic Chemistry published new progress about 64987-16-2. 64987-16-2 belongs to thiazole, auxiliary class Thiazole,Amine,Ester, name is Methyl 2-(2-aminothiazol-4-yl)acetate, and the molecular formula is C6H8N2O2S, Quality Control of 64987-16-2.

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