Category: 272437-84-0

3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, cas is 272437-84-0, it is a common heterocyclic compound, the thiazines compound, its synthesis route is as follows.

To a solution of 3-oxo-3, 4-dihydro-2H-1, 4-benzothiazin-6- carboxylic acid (3.6 g, 17 mmol) in DMF (50 ML) were added WSC (3.8 g, 20 mmol), HOBt (3.1 g, 20 mmol) and 2.0 M dimethylamine-THF solution (12.5 ML, 25 mmol), and the mixture was stirred at room temperature for 12 hrs. Saturated aqueous sodium hydrogen carbonate was poured into the reaction solution and the mixture was extracted with ethyl acetate. The extract was washed with 1N hydrochloric acid and saturated brine, dried (MGS04) and concentrated under reduced pressure. The residue was crystallized from diisopropyl ether to give the title compound as pale yellow crystals (3.6 g, yield 90%). OH NMR (300 MHz, DMSO-D6) 8 ppm: 2.91 (br, 6 H), 3.49 (s, 2 H), 6. 96-7. 00 (m, 2 H), 7. 35 (d, J = 8. 4 Hz, 1 H).

272437-84-0, In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles.,272437-84-0 ,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, other downstream synthetic routes, hurry up and to see

Reference£º
Patent; TAKEDA CHEMICAL INDUSTRIES, LTD.; WO2004/46107; (2004); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

It is a common heterocyclic compound, the thiazines compound, 3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, cas is 272437-84-0 its synthesis route is as follows.

Preparation of 3-oxo-3,4-dihvdro-2H-benzori,41thiazine-6-carboxylic acid (l-[2-(7- methoxy-quinoxalin-2-yloxy)-ethvH-piperidin-4-vU -amide: 3-Oxo-3,4-dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid (60 mg, 0.26 mmol, 1.0 eq) is added at room temperature to a stirred solution of l-[2-(7-methoxy-quinoxalin-2-yloxy)- ethyl]-piperidin-4-ylamine (80 mg, 0.26 mmol, 1.0 eq) in N,N-dimethylformamide (5 mL), followed by 1-hydroxybenzotriazole (38 mg, 0.29 mmol, 1.1 eq), N-Q- dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (57 mg, 0.30 mmol, 1.15 eq) and N,N-diisopropylethylamine (100 muL, 0.58 mmol, 2.25 eq). After 15 hours stirring at room temperature, solvent is evaporated and the residue is extracted with dichloromethane (3 x 10 mL) and water (10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a residue that is purified by preparative EtaPLC to afford 3-oxo-3,4- dihydro-2H-benzo[ 1 ,4]thiazine-6-carboxylic acid { 1 -[2-(7-methoxy-quinoxalin-2-yloxy)- ethyl]-piperidin-4-yl} -amide as an off-white solid (18 mg, 13% yield).1H-NMR (400 MHz, DMSO-t/6) delta ppm: 10.65 (s, IH), 8.42 (s,lH), 8.22 (d, J = 7.8 Hz, IH), 7.89 (d, J = 9.0 Hz, IH), 7.38-7.46 (m, 3H), 7.22-7.28 (m, 2H), 4.56 (t, J = 5.8 Hz, 2H), 3.92 (s, 3H), 3.75 (m, IH), 3.50 (s, 2H), 3.00 (m, 2H), 2.81 (t, J = 5.8 Hz, 2H), 2.18 (m, 2H), 1.79 (m, 2H), 1.55 (m, 2H).MS m/z (+ESI): 494.4 [M+H]+.

272437-84-0, In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles.,272437-84-0 ,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, other downstream synthetic routes, hurry up and to see

Reference£º
Patent; BASILEA PHARMACEUTICA AG; GAUCHER, Berangere; DANEL, Franck Hubert; ROUSSEL, Patrick; WO2010/84152; (2010); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route. 272437-84-0

Preparation of 4-[(3-oxo-3,4-dihydro-2H-benzo[l ,41thiazine-6-carbonyl)-aminol-piperidine- 1-carboxylic acid tert-butyl ester:3-Oxo-3,4-dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid (556 mg, 2.45 mmol, 1.0 eq) is added at room temperature to a stirred solution of 4-amino-piperidine- 1-carboxylic acid tert- butyl ester (500 mg, 2.45 mmol, 1.0 eq) in N,N-dimethylformamide (20 mL), followed by 1- hydroxybenzotriazole (421 mg, 2.69 mmol, 1.1 eq), N-(3-dimethylaminopropyl)-N’- ethylcarbodiimide hydrochloride (550 mg, 2.81 mmol, 1.15 eq) and N,N- diisopropylethylamine (962 L, 5.50 mmol, 2.25 eq). After 15 hours stirring at room temperature, solvent is evaporated and the residue is extracted with dichloromethane (3 x 30 – – mL) and water (30 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a crude product that is purified by column chromatography (silica gel, eluent: cyclohexane:ethyl acetate :methanol, 1 :3:0 to 0/9/1, v/v/v) to afford 4-[(3-oxo-3,4- dihydro-2H-benzo [ 1 ,4]thiazine-6-carbonyl)-amino ] -piperidine- 1 -carboxylic acid tert-butyl ester as a light yellow solid (621 mg, 62% yield).1H-NMR (400 MHz, DMSO- 6) delta ppm: 10.66 (s, 1H), 8.27 (d, J = 7.8 Hz, 1H), 7.42 (m, 3H), 3.96 (m, 3H), 3.51 (s, 2H), 2.90 (m, 2H), 1.76 (m, 2H), 1.40 (m, 11H).MS m/z (+ESI): 392.3 [M+H]+, 414.3 [M+Na]+.

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,its application will become more common.

Reference£º
Patent; BASILEA PHARMACEUTICA AG; GAUCHER, Berangere; DANEL, Franck Hubert; XIE, Tong; XU, Lin; WO2012/171860; (2012); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route. 272437-84-0

To a solution of 3-oxo-3, 4-dihydro-2H-1, 4-benzothiazin-6- carboxylic acid (3.6 g, 17 mmol) in DMF (50 ML) were added WSC (3.8 g, 20 mmol), HOBt (3.1 g, 20 mmol) and 2.0 M dimethylamine-THF solution (12.5 ML, 25 mmol), and the mixture was stirred at room temperature for 12 hrs. Saturated aqueous sodium hydrogen carbonate was poured into the reaction solution and the mixture was extracted with ethyl acetate. The extract was washed with 1N hydrochloric acid and saturated brine, dried (MGS04) and concentrated under reduced pressure. The residue was crystallized from diisopropyl ether to give the title compound as pale yellow crystals (3.6 g, yield 90%). OH NMR (300 MHz, DMSO-D6) 8 ppm: 2.91 (br, 6 H), 3.49 (s, 2 H), 6. 96-7. 00 (m, 2 H), 7. 35 (d, J = 8. 4 Hz, 1 H).

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,272437-84-0,its application will become more common.

Reference£º
Patent; TAKEDA CHEMICAL INDUSTRIES, LTD.; WO2004/46107; (2004); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route. 272437-84-0

Preparation of 3-oxo-3,4-dihydro-2H-benzo[l,41thiazine-6-carboxylic acid [tra/? -4-(8- methoxy-l,2-dihydro-3-oxa-5,9-diaza-cyclopenta[alnaphthalen-2-ylmethyl)-cyclohexyll- amide:3-Oxo-3,4-dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid (31 mg, 0.14 mmol, 1.0 eq) is added at room temperature to a stirred solution of tra?s-4-(8-methoxy-l,2-dihydro-3-oxa-5,9- diaza-cyclopenta[a]naphthalen-2-ylmethyl)-cyclohexylamine (47 mg, 0.14 mmol, 1.0 eq) in N,N-dimethylformamide (4 mL), followed by 1-hydroxybenzotriazole (24 mg, 0.16 mmol, 1.1 eq), N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (32 mg, 0.16 mmol, 1.15 eq) and NN-diisopropylethylamine (56 mu, 0.32 mmol, 2.25 eq). After 15 hours stirring at room temperature, solvent is evaporated and the residue is extracted with dichloromethane (3 x 10 mL) and water (10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a crude product that is purified by preparative HPLC to afford 3-oxo-3,4- dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid [tra?s-4-(8-methoxy-l,2-dihydro-3-oxa- – -5,9-diaza-cyclopenta[a]naphthalen-2-ylmethyl)-cyclohexyl]-amide as a white lyophilized powder (16 mg, 21% yield).1H-NMR (400 MHz, DMSO- 6) delta ppm: 10.67 (s, 1H), 8.49 (s, 1H), 8.23 (d, J = 7.9 Hz, 1H), 8.19 (d, J = 9.0 Hz, 1H), 7.44 (m, 3H), 7.06 (d, J = 9.1 Hz, 1H), 5.21 (m, 1H), 4.01 (s, 3H), 3.74 (m, 2H), 3.51 (s, 2H), 3.14 (dd, J = 7.9, 16.8 Hz, 1H), 1.80-2.00 (m, 5H), 1.66 (m, 1H), 1.57 (m, 1H), 1.39 (m, 2H), 1.13 (m, 2H).MS m/z (+ESI): 505.5 [M+H]+.

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,its application will become more common.

Reference£º
Patent; BASILEA PHARMACEUTICA AG; GAUCHER, Berangere; DANEL, Franck Hubert; XIE, Tong; XU, Lin; WO2012/171860; (2012); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route. 272437-84-0

Preparation of 3-oxo-3,4-dihvdro-2H-benzori,41thiazine-6-carboxylic acid (l-[2-(7- methoxy-quinoxalin-2-yloxy)-ethvH-piperidin-4-vU -amide: 3-Oxo-3,4-dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid (60 mg, 0.26 mmol, 1.0 eq) is added at room temperature to a stirred solution of l-[2-(7-methoxy-quinoxalin-2-yloxy)- ethyl]-piperidin-4-ylamine (80 mg, 0.26 mmol, 1.0 eq) in N,N-dimethylformamide (5 mL), followed by 1-hydroxybenzotriazole (38 mg, 0.29 mmol, 1.1 eq), N-Q- dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (57 mg, 0.30 mmol, 1.15 eq) and N,N-diisopropylethylamine (100 muL, 0.58 mmol, 2.25 eq). After 15 hours stirring at room temperature, solvent is evaporated and the residue is extracted with dichloromethane (3 x 10 mL) and water (10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a residue that is purified by preparative EtaPLC to afford 3-oxo-3,4- dihydro-2H-benzo[ 1 ,4]thiazine-6-carboxylic acid { 1 -[2-(7-methoxy-quinoxalin-2-yloxy)- ethyl]-piperidin-4-yl} -amide as an off-white solid (18 mg, 13% yield).1H-NMR (400 MHz, DMSO-t/6) delta ppm: 10.65 (s, IH), 8.42 (s,lH), 8.22 (d, J = 7.8 Hz, IH), 7.89 (d, J = 9.0 Hz, IH), 7.38-7.46 (m, 3H), 7.22-7.28 (m, 2H), 4.56 (t, J = 5.8 Hz, 2H), 3.92 (s, 3H), 3.75 (m, IH), 3.50 (s, 2H), 3.00 (m, 2H), 2.81 (t, J = 5.8 Hz, 2H), 2.18 (m, 2H), 1.79 (m, 2H), 1.55 (m, 2H).MS m/z (+ESI): 494.4 [M+H]+., 272437-84-0

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,its application will become more common.

Reference£º
Patent; BASILEA PHARMACEUTICA AG; GAUCHER, Berangere; DANEL, Franck Hubert; ROUSSEL, Patrick; WO2010/84152; (2010); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route. 272437-84-0

272437-84-0, Preparation of 3-oxo-3,4-dihvdro-2H-benzori,41thiazine-6-carboxylic acid (l-[2-(7- methoxy-quinoxalin-2-ylsulfanyl)-ethvH-piperidin-4-vU -methyl-amide: 3-oxo-3,4-dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid (26 mg, 0.11 mmol, 1.0 eq) is added at room temperature to a stirred solution of {l-[2-(7-methoxy-quinoxalin-2- ylsulfanyl)-ethyl]-piperidin-4-yl}-methyl-amine (40 mg, 0.11 mmol, 1.0 eq) in N,N- dimethylformamide (3 mL), followed by O-(7-azabenzotriazol-l-yl)-iV,iV,N’,N’- tetramethyluronium hexafluorophosphate (45 mg, 0.11 mmol, 1.0 eq), and triethylamine (16 muL, 0.11 mmol, 1.0 eq). After 4 hours stirring at room temperature, solvent is evaporated and the residue is purified by preparative EtaPLC to afford 3-oxo-3,4-dihydro-2H- benzo[l,4]thiazine-6-carboxylic acid {l-[2-(7-methoxy-quinoxalin-2-ylsulfanyl)-ethyl]- piperidin-4-yl} -methyl-amide as a yellow solid (22 mg, 35% yield).MS m/z (+ESI): 524.3 [M+Eta]”

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,272437-84-0,its application will become more common.

Reference£º
Patent; BASILEA PHARMACEUTICA AG; GAUCHER, Berangere; DANEL, Franck Hubert; ROUSSEL, Patrick; WO2010/84152; (2010); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

272437-84-0 A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.

Preparation of 3-oxo-3,4-dihydro-2H-benzo[l,41thiazine-6-carboxylic acid [tra/? -4-(8- methoxy-l,2-dihydro-3-oxa-5,9-diaza-cyclopenta[alnaphthalen-2-ylmethyl)-cyclohexyll- amide:3-Oxo-3,4-dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid (31 mg, 0.14 mmol, 1.0 eq) is added at room temperature to a stirred solution of tra?s-4-(8-methoxy-l,2-dihydro-3-oxa-5,9- diaza-cyclopenta[a]naphthalen-2-ylmethyl)-cyclohexylamine (47 mg, 0.14 mmol, 1.0 eq) in N,N-dimethylformamide (4 mL), followed by 1-hydroxybenzotriazole (24 mg, 0.16 mmol, 1.1 eq), N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (32 mg, 0.16 mmol, 1.15 eq) and NN-diisopropylethylamine (56 mu, 0.32 mmol, 2.25 eq). After 15 hours stirring at room temperature, solvent is evaporated and the residue is extracted with dichloromethane (3 x 10 mL) and water (10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a crude product that is purified by preparative HPLC to afford 3-oxo-3,4- dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid [tra?s-4-(8-methoxy-l,2-dihydro-3-oxa- – -5,9-diaza-cyclopenta[a]naphthalen-2-ylmethyl)-cyclohexyl]-amide as a white lyophilized powder (16 mg, 21% yield).1H-NMR (400 MHz, DMSO- 6) delta ppm: 10.67 (s, 1H), 8.49 (s, 1H), 8.23 (d, J = 7.9 Hz, 1H), 8.19 (d, J = 9.0 Hz, 1H), 7.44 (m, 3H), 7.06 (d, J = 9.1 Hz, 1H), 5.21 (m, 1H), 4.01 (s, 3H), 3.74 (m, 2H), 3.51 (s, 2H), 3.14 (dd, J = 7.9, 16.8 Hz, 1H), 1.80-2.00 (m, 5H), 1.66 (m, 1H), 1.57 (m, 1H), 1.39 (m, 2H), 1.13 (m, 2H).MS m/z (+ESI): 505.5 [M+H]+.

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,272437-84-0,its application will become more common.

Reference£º
Patent; BASILEA PHARMACEUTICA AG; GAUCHER, Berangere; DANEL, Franck Hubert; XIE, Tong; XU, Lin; WO2012/171860; (2012); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

272437-84-0 A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.

Preparation of 3-oxo-3,4-dihvdro-2H-benzori,41thiazine-6-carboxylic acid (l-[2-(6- methoxy-quinolin-3-ylsulfanyl)-ethyll-piperidin-4-vU -amide: 3-oxo-3,4-dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid (21 mg, 0.09 mmol, 1.0 eq) is added at room temperature to a stirred solution of l-[2-(6-methoxy-quinolin-3-ylsulfanyl)- ethyl]-piperidin-4-ylamine (30 mg, 0.09 mmol, 1.0 eq) in N,N-dimethylformamide (3 mL), followed by 1-hydroxybenzotriazole (13 mg, 0.10 mmol, 1.1 eq), N-Q- dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (20 mg, 0.10 mmol, 1.15 eq) and N,N-diisopropylethylamine (35 muL, 0.20 mmol, 2.25 eq). After 15 hours stirring at room temperature, solvent is evaporated and the residue is extracted with dichloromethane (3 x 5 mL) and water (5 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a residue that is purified by preparative EtaPLC to afford 3-oxo-3,4- dihydro-2H-benzo[l,4]thiazine-6-carboxylic acid {l-[2-(6-methoxy-quinolin-3- ylsulfanyl)-ethyl]-piperidin-4-yl} -amide as a white solid (30 mg, 59% yield).1H-NMR (400 MHz, DMSO-t/6) delta ppm: 11.65 (s, IH), 8.65 (d, J = 2.5 Hz, IH), 8.20-8.25 (m, 2H), 7.88 (d, J = 8.8 Hz, IH), 7.30-7.45 (m, 5H), 3.93 (s, 3H), 3.75 (m, IH), 3.50 (s, 2H), 3.29 (t, J = 7.0 Hz, 2H), 2.95 (m, 2H), 2.66 (t, J = 7.0 Hz, 2H), 2.11 (m, 2H), 1.78 (m, 2H), 1.58 (m, 2H). MS m/z (+ESI): 509.3 [M+H]+.

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,its application will become more common.

Reference£º
Patent; BASILEA PHARMACEUTICA AG; GAUCHER, Berangere; DANEL, Franck Hubert; ROUSSEL, Patrick; WO2010/84152; (2010); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem

272437-84-0 A common heterocyclic compound, 272437-84-0,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.

Acid (4a) in tetrahydrofuran (SOmL) and triethylamine (4.7mL) was cooled to 0C and isobutylchloroformate (4.02mL) was added dropwise and the solution was stirred at 0C for 2 hours, when it was filtered into a stirred solution of sodium borohydride (3. 14g) in ice/water (50mL). The mixture was stirred at 0C for 1 hour and allowed to warm to room temperature. It was acidified with 2M hydrochloric acid, evaporated to half volume, and the resulting product was collected, washed with water and dried in vacuo, to give a white solid (4. 5g). MS (-ve ion electrospray) m/z 194 (M-H)-

This compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid,272437-84-0,its application will become more common.

Reference£º
Patent; SMITHKLINE BEECHAM P.L.C.; WO2003/87098; (2003); A1;,
Thiazine – an overview | ScienceDirect Topics
Thiazine | C4H5NS – PubChem