Molecular formula
C19H15N3O3S
151 compounds have this formula on CompoundList.
- Molar mass
- 365.41g/mol
- Monoisotopic mass
- 365.0834Da
- Atoms
- 41
- Elements
- 5
- Rings plus double bonds
- 14
The formula C19H15N3O3S describes a molecule made of 19 carbon atoms, 15 hydrogen atoms, 3 nitrogen atoms, 3 oxygen atoms and 1 sulfur atom. It is written in Hill notation: carbon first, then hydrogen, then the other elements in alphabetical order. The formula tells you which atoms are present, not how they are connected, which is why several different chemicals can share it.
Elemental composition
- C Carbon × 1962.45%12.011 × 19 = 228.209 g/mol
- H Hydrogen × 154.14%1.008 × 15 = 15.120 g/mol
- N Nitrogen × 311.50%14.007 × 3 = 42.021 g/mol
- O Oxygen × 313.14%15.999 × 3 = 47.997 g/mol
- S Sulfur × 18.77%32.06 × 1 = 32.060 g/mol
Look up another formula
Compounds with the formula C19H15N3O3S
Isomers we list, best known first. Open one to see its structure, properties, safety data and suppliers.
Showing 1 to 100 of 151 compounds
![(3E)-3-[2-[(4-Hydroxyphenyl)(methyl)amino]-4-oxo-1,3-thiazol-5(4H)-ylidene]-5-methyl-1,3-dihydro-2H-indol-2-one chemical structure, C19H15N3O3S, CAS 432006-05-8](/s/FJPLXZMXEXRDMC-UHFFFAOYSA-N.svg)
(3E)-3-[2-[(4-Hydroxyphenyl)(methyl)amino]-4-oxo-1,3-thiazol-5(4H)-ylidene]-5-methyl-1,3-dihydro-2H-indol-2-one
CAS 432006-05-8C19H15N3O3S
![N-(Furan-2-ylmethyl)-2-(4-oxo-5-phenylthieno[2,3-d]pyrimidin-3-yl)acetamide chemical structure, C19H15N3O3S, CAS 433690-12-1](/s/LFTFRAZVOJFTMX-UHFFFAOYSA-N.svg)
N-(Furan-2-ylmethyl)-2-(4-oxo-5-phenylthieno[2,3-d]pyrimidin-3-yl)acetamide
CAS 433690-12-1C19H15N3O3S
N'-(4,6-Dimethyl-1,3-benzothiazol-2-yl)-4-oxochromene-2-carbohydrazide
CAS 851987-28-5C19H15N3O3S
![5-Oxo-N-(4-phenoxyphenyl)-2,3-dihydro-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxamide chemical structure, C19H15N3O3S, CAS 532965-52-9](/s/FJGYYALBERLCNB-UHFFFAOYSA-N.svg)
5-Oxo-N-(4-phenoxyphenyl)-2,3-dihydro-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxamide
CAS 532965-52-9C19H15N3O3S
4-(2,5-Dioxopyrrolidin-1-yl)-N-(2-methyl-1,3-benzothiazol-5-yl)benzamide
CAS 476281-71-7C19H15N3O3S
![2-[[5-(1-Benzofuran-2-yl)-4-phenyl-1,2,4-triazol-3-yl]sulfanyl]propanoic acid chemical structure, C19H15N3O3S, CAS 832687-69-1](/s/HEAYNQCRWKRREM-UHFFFAOYSA-N.svg)
2-[[5-(1-Benzofuran-2-yl)-4-phenyl-1,2,4-triazol-3-yl]sulfanyl]propanoic acid
CAS 832687-69-1C19H15N3O3S
![N-[2-Oxo-1-(4-oxo-2-sulfanylidene-1H-pyrimidin-3-yl)-2-phenylethyl]benzamide chemical structure, C19H15N3O3S, CAS 300667-91-8](/s/FXQHZKQXHQFHHE-UHFFFAOYSA-N.svg)
N-[2-Oxo-1-(4-oxo-2-sulfanylidene-1H-pyrimidin-3-yl)-2-phenylethyl]benzamide
CAS 300667-91-8C19H15N3O3S
4-Hydroxy-1-methyl-N-(6-methyl-1,3-benzothiazol-2-yl)-2-oxo-1,2-dihydro-3-quinolinecarboxamide
CAS 423145-53-3C19H15N3O3S
![N-(4-(2,3-Dihydroimidazo[2,1-b]thiazol-6-yl)phenyl)benzo[d][1,3]dioxole-5-carboxamide chemical structure, C19H15N3O3S, CAS 893995-95-4](/s/AOGXBRAWKJHJEZ-UHFFFAOYSA-N.svg)
N-(4-(2,3-Dihydroimidazo[2,1-b]thiazol-6-yl)phenyl)benzo[d][1,3]dioxole-5-carboxamide
CAS 893995-95-4C19H15N3O3S
N'-(4,5-Dimethyl-1,3-benzothiazol-2-yl)-4-oxochromene-2-carbohydrazide
CAS 851980-51-3C19H15N3O3S
![2-[[3,5-Dimethyl-1-(thiophene-2-carbonyl)pyrazol-4-yl]methyl]isoindole-1,3-dione chemical structure, C19H15N3O3S, CAS 890604-18-9](/s/DWWQWDCINYNCAO-UHFFFAOYSA-N.svg)
2-[[3,5-Dimethyl-1-(thiophene-2-carbonyl)pyrazol-4-yl]methyl]isoindole-1,3-dione
CAS 890604-18-9C19H15N3O3S
5-Methoxy-3-methyl-N-(4-pyridin-2-yl-1,3-thiazol-2-yl)-1-benzofuran-2-carboxamide
CAS 930898-33-2C19H15N3O3S
N-(1,3-Benzothiazol-2-yl)-1-ET-4-HO-2-oxo-1,2-dihydro-3-quinolinecarboxamide
CAS 300716-43-2C19H15N3O3S
![2-(Benzofuro[3,2-d]pyrimidin-4-ylthio)-N-(3-methoxyphenyl)acetamide chemical structure, C19H15N3O3S, CAS 848682-17-7](/s/YOCMGFNXMSXRSF-UHFFFAOYSA-N.svg)
2-(Benzofuro[3,2-d]pyrimidin-4-ylthio)-N-(3-methoxyphenyl)acetamide
CAS 848682-17-7C19H15N3O3S
![4-(2,5-Dioxopyrrolidin-1-yl)-N-(2-methylbenzo[d]thiazol-6-yl)benzamide chemical structure, C19H15N3O3S, CAS 330200-78-7](/s/JDUOJICUBSDFRK-UHFFFAOYSA-N.svg)
4-(2,5-Dioxopyrrolidin-1-yl)-N-(2-methylbenzo[d]thiazol-6-yl)benzamide
CAS 330200-78-7C19H15N3O3S
2-(2,5-Dioxopyrrolidin-1-yl)-N-(4-(naphthalen-2-yl)thiazol-2-yl)acetamide
CAS 476308-67-5C19H15N3O3S
![N-[4-(Benzoylcarbamothioylamino)phenyl]furan-2-carboxamide chemical structure, C19H15N3O3S, CAS 425653-72-1](/s/RSVVCFDJULSZFS-UHFFFAOYSA-N.svg)
N-[4-(Benzoylcarbamothioylamino)phenyl]furan-2-carboxamide
CAS 425653-72-1C19H15N3O3S
![N-[3-(2,3-Dihydroimidazo[2,1-b][1,3]thiazol-6-yl)phenyl]-1,3-benzodioxole-5-carboxamide chemical structure, C19H15N3O3S, CAS 872630-17-6](/s/OBEIMTKNOOWYOM-UHFFFAOYSA-N.svg)
N-[3-(2,3-Dihydroimidazo[2,1-b][1,3]thiazol-6-yl)phenyl]-1,3-benzodioxole-5-carboxamide
CAS 872630-17-6C19H15N3O3S
Phenithionate
CAS 83538-74-3C19H15N3O3S
![1-(2-Methylphenyl)-3-[(5-phenyl-1,3,4-oxadiazol-2-yl)sulfanyl]pyrrolidine-2,5-dione chemical structure, C19H15N3O3S, CAS 522660-29-3](/s/OMRMVTBAHXDHNA-UHFFFAOYSA-N.svg)
1-(2-Methylphenyl)-3-[(5-phenyl-1,3,4-oxadiazol-2-yl)sulfanyl]pyrrolidine-2,5-dione
CAS 522660-29-3C19H15N3O3S
![N-(4,5-Dimethylbenzo[d]thiazol-2-yl)-2-(1,3-dioxoisoindolin-2-yl)acetamide chemical structure, C19H15N3O3S, CAS 888409-66-3](/s/YOIUMSMNFQFUCE-UHFFFAOYSA-N.svg)
N-(4,5-Dimethylbenzo[d]thiazol-2-yl)-2-(1,3-dioxoisoindolin-2-yl)acetamide
CAS 888409-66-3C19H15N3O3S
![2-([1]Benzofuro[3,2-d]pyrimidin-4-ylsulfanyl)-N-(2-methoxyphenyl)acetamide chemical structure, C19H15N3O3S, CAS 848222-10-6](/s/GNYHMFMPAMLLIT-UHFFFAOYSA-N.svg)
2-([1]Benzofuro[3,2-d]pyrimidin-4-ylsulfanyl)-N-(2-methoxyphenyl)acetamide
CAS 848222-10-6C19H15N3O3S
5-(2,4-Dimethoxybenzylidene)-2-PH(1,3)thiazolo(3,2-B)(1,2,4)triazol-6(5H)-one
CAS 606960-78-5C19H15N3O3S
5-(3,4-Dimethoxybenzylidene)-2-PH(1,3)thiazolo(3,2-B)(1,2,4)triazol-6(5H)-one
CAS 606949-54-6C19H15N3O3S
- 5-(Benzo[d][1,3]dioxol-5-yl)-2-(p-tolyl)-5H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7(6H)-one433330-16-6C19H15N3O3S
- N-(1,3-Benzothiazol-2-yl)-4-(1,3-dioxoisoindol-2-yl)butanamide378206-92-9C19H15N3O3S
- (E)-N-(3,6-Dimethylbenzo[d]thiazol-2(3H)-ylidene)-2-(1,3-dioxoisoindolin-2-yl)acetamide477294-80-7C19H15N3O3S
- N-[(3-Benzamidophenyl)carbamothioyl]furan-2-carboxamide355412-04-3C19H15N3O3S
- Cambridge id 7215675379249-72-6C19H15N3O3S
- N-(6-Methoxybenzo[d]thiazol-2-yl)-N-(pyridin-3-ylmethyl)furan-2-carboxamide895010-92-1C19H15N3O3S
- 1-(4-(Benzofuran-2-yl)thiazol-2-yl)-3-(3-methoxyphenyl)urea716376-45-3C19H15N3O3S
- N-(5-Methoxybenzo[d]thiazol-2-yl)-N-(pyridin-3-ylmethyl)furan-2-carboxamide895412-73-4C19H15N3O3S
- N-(4-Methoxybenzo[d]thiazol-2-yl)-N-(pyridin-3-ylmethyl)furan-2-carboxamide895003-51-7C19H15N3O3S
- (E)-N-(4-(4-Cyanophenyl)thiazol-2(3H)-ylidene)-2,4-dimethoxybenzamide313647-79-9C19H15N3O3S
- N-[3-(4-Methoxyphenyl)-1,2,4-thiadiazol-5-yl]-3-methyl-1-benzofuran-2-carboxamide898623-45-5C19H15N3O3S
- 2-Cyano-3-[1-(4-methylbenzenesulfonyl)-1H-indol-3-yl]prop-2-enamide444099-89-2C19H15N3O3S
- 2-Oxo-N-(4-phenylphenyl)-1,3-dihydrobenzimidazole-5-sulfonamide692761-84-5C19H15N3O3S
- 5-Cyano-4-(furan-2-yl)-N-(2-methoxyphenyl)-2-methyl-6-thioxo-1,6-dihydropyridine-3-carboxamide370074-51-4C19H15N3O3S
- N-(4,7-Dimethyl-1,3-benzothiazol-2-yl)-2-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)acetamide912766-38-2C19H15N3O3S
- (5Z)-5-(4-Methoxybenzylidene)-2-(4-methoxyphenyl)[1,3]thiazolo[3,2-b][1,2,4]triazol-6(5H)-one58755-13-8C19H15N3O3S
- N-(5-Methoxybenzo[d]thiazol-2-yl)-N-(pyridin-2-ylmethyl)furan-2-carboxamide899964-38-6C19H15N3O3S
- (2E)-N-(5-Methyl-4-phenyl-1,3-thiazol-2-yl)-3-(4-nitrophenyl)prop-2-enamide352346-10-2C19H15N3O3S
- N-(4-Methoxyphenyl)-2-{6-oxo-8-thia-3,5-diazatricyclo[7.4.0.0^{2,7}]trideca-1(13),2(7),3,9,11-pentaen-5-yl}acetamide1021207-32-8C19H15N3O3S
- 2-(2-Methyl-1H-indol-3-yl)-2-oxo-N-((5-(thiophen-2-yl)isoxazol-3-yl)methyl)acetamide946345-42-2C19H15N3O3S
- N-(5-(4-(Methylthio)benzyl)-1,3,4-oxadiazol-2-yl)benzofuran-2-carboxamide1172815-80-3C19H15N3O3S
- (6Z)-6-[(2,4-Dimethoxyphenyl)methylidene]-3-phenyl-[1,3]thiazolo[2,3-c][1,2,4]triazol-5-one328090-40-0C19H15N3O3S
- 2-(Benzofuro[3,2-d]pyrimidin-4-ylthio)-N-(4-methoxyphenyl)acetamide848689-93-0C19H15N3O3S
- 8-Methoxy-3-(5-(p-tolylamino)-1,3,4-thiadiazol-2-yl)-2H-chromen-2-one326913-60-4C19H15N3O3S
- N-[4-(4-Nitrophenyl)-1,3-thiazol-2-yl]-2-phenylcyclopropanecarboxamide424807-28-3C19H15N3O3S
- Nlrp3-IN-131704638-35-6C19H15N3O3S
- 8-Ethoxy-3-[5-(phenylamino)-1,3,4-thiadiazol-2-yl]-2H-chromen-2-one326913-44-4C19H15N3O3S
- 2-Amino-4-(furan-2-yl)-7-methyl-5-oxo-6-(thiophen-2-ylmethyl)-5,6-dihydro-4H-pyrano[3,2-c]pyridine-3-carbonitrile638138-82-6C19H15N3O3S
- N-(2-Furylmethyl)-2-(4-oxo-7-phenylthieno[3,2-d]pyrimidin-3(4H)-yl)acetamide1105235-03-7C19H15N3O3S
- N-(5-Ethyl-1,3,4-thiadiazol-2-yl)-4-[oxo(phenyl)acetyl]benzamide307544-93-0C19H15N3O3S
- 2-Amino-6-(furan-2-ylmethyl)-7-methyl-5-oxo-4-(thiophen-2-yl)-5,6-dihydro-4H-pyrano[3,2-c]pyridine-3-carbonitrile638139-02-3C19H15N3O3S
- N-(6-Methoxy-1,3-benzothiazol-2-yl)-5-methyl-3-phenyl-1,2-oxazole-4-carboxamide431998-16-2C19H15N3O3S
- (E)-4-(2,5-Dioxopyrrolidin-1-yl)-N-(3-methylbenzo[d]thiazol-2(3H)-ylidene)benzamide307327-07-7C19H15N3O3S
- N-(Quinolin-5-ylcarbamothioyl)-2,3-dihydro-1,4-benzodioxine-6-carboxamide712292-47-2C19H15N3O3S
- N-[4-(4-Methylphenyl)-1,3-thiazol-2-yl]-2-(2-oxo-1,3-benzoxazol-3-yl)acetamide874584-65-3C19H15N3O3S
- N-(4,5-Dihydroacenaphtho[5,4-d]thiazol-8-yl)-2-(2,5-dioxopyrrolidin-1-yl)acetamide477326-07-1C19H15N3O3S
- N-(4-Hydroxyphenyl)-2-({4-methyl-8-oxa-3,5-diazatricyclo[7.4.0.0^{2,7}]trideca-1(9),2(7),3,5,10,12-hexaen-6-yl}sulfanyl)acetamide848690-09-5C19H15N3O3S
- N-(4,6-Dimethylbenzo[d]thiazol-2-yl)-2-(1,3-dioxoisoindolin-2-yl)acetamide361478-52-6C19H15N3O3S
- 2-[(3-Nitrophenyl)imino]-5-(phenylmethylidene)-3-(prop-2-en-1-yl)-1,3-thiazolidin-4-one327090-70-0C19H15N3O3S
- (4Z,5Z)-4-((4-Ethoxyphenyl)imino)-5-(2-oxoindolin-3-ylidene)thiazolidin-2-one465505-24-2C19H15N3O3S
- N-[[2-(Phenylcarbamoyl)phenyl]carbamothioyl]furan-2-carboxamide642957-36-6C19H15N3O3S
- N-(Furan-2-ylmethyl)-2-((5-phenylthieno[2,3-d]pyrimidin-4-yl)oxy)acetamide729579-66-2C19H15N3O3S
- 3-Methoxy-N-(5-(thiophen-2-ylmethyl)-1,3,4-oxadiazol-2-yl)-2-naphthamide1021112-95-7C19H15N3O3S
- 5-(Furan-2-yl)-N-(pyridin-2-ylmethyl)-N-(thiophen-3-ylmethyl)isoxazole-3-carboxamide1286726-92-8C19H15N3O3S
- N-(4-(2-Carbamoylphenoxy)but-2-yn-1-yl)benzo[d]thiazole-2-carboxamide1421500-59-5C19H15N3O3S
- 4(3H)-Quinazolinone, 2-((o-methoxyphenoxy)methyl)-3-(2-thiazolyl)-73342-49-1C19H15N3O3S
- (5E)-5-(1H-Benzimidazol-2-ylmethylidene)-3-(4-ethoxyphenyl)-1,3-thiazolidine-2,4-dione881818-18-4C19H15N3O3S
- (5Z)-5-Benzylidene-2-(3,4-dimethoxyphenyl)[1,3]thiazolo[3,2-b][1,2,4]triazol-6(5H)-one578732-48-6C19H15N3O3S
- N-(3-Methoxyphenyl)-9-methyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-2-carboxamide689745-77-5C19H15N3O3S
- N-[4-(4-Cyanophenyl)-1,3-thiazol-2-yl]-3,5-dimethoxybenzamide391220-51-2C19H15N3O3S
- N-(4-{3-Nitrophenyl}-1,3-thiazol-2-yl)-3-(4-methylphenyl)acrylamide444923-30-2C19H15N3O3S
- (5Z)-2-[(E)-2-(4-Methoxyphenyl)ethenyl]-5-[(5-methylfuran-2-yl)methylidene][1,3]thiazolo[3,2-b][1,2,4]triazol-6(5H)-one847272-08-6C19H15N3O3S
- N'-(4,5-Dimethylbenzo[d]thiazol-2-yl)-4-oxo-4H-chromene-3-carbohydrazide851980-58-0C19H15N3O3S
- N-(3-(Methylthio)phenyl)-2-(4-oxobenzofuro[3,2-d]pyrimidin-3(4H)-yl)acetamide1002064-10-9C19H15N3O3S
- N-(4-Methoxyphenyl)-12-methyl-2-oxo-6-thia-1,8-diazatricyclo[7.4.0.0^{3,7}]trideca-3(7),4,8,10,12-pentaene-5-carboxamide1021260-61-6C19H15N3O3S
- N-(3-Methoxyphenyl)-7-methyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-2-carboxamide1021212-51-0C19H15N3O3S
- N-(2-Methoxyphenyl)-7-methyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-2-carboxamide1021260-76-3C19H15N3O3S
- 1-(5-(Furan-2-yl)isoxazol-3-yl)-N-(4-methylbenzo[d]thiazol-2-yl)cyclopropanecarboxamide1286705-59-6C19H15N3O3S
- N-(6-Methoxy-1,3-benzothiazol-2-yl)-1-methyl-2-oxo-1,2-dihydroquinoline-4-carboxamide1374537-52-6C19H15N3O3S
- 3-Methoxy-N-[4-(6-methyl-1,3-benzothiazol-2-yl)phenyl]-1,2-oxazole-5-carboxamide1428358-55-7C19H15N3O3S
- 1'-(2,1,3-Benzothiadiazole-5-carbonyl)-3,4-dihydrospiro[1-benzopyran-2,3'-pyrrolidine]-4-one1448133-16-1C19H15N3O3S
- N-(2-((3-(Furan-2-yl)-1,2,4-oxadiazol-5-yl)methyl)phenyl)-2-(thiophen-3-yl)acetamide1797859-11-0C19H15N3O3S
- 4-Oxo-N-(2-(3-(thiophen-3-yl)-1H-pyrazol-1-yl)ethyl)-4H-chromene-2-carboxamide2034451-67-5C19H15N3O3S
- 2-(2-Oxobenzo[d]oxazol-3(2H)-yl)-N-((2-(thiophen-3-yl)pyridin-3-yl)methyl)acetamide2034564-30-0C19H15N3O3S
- 2-(2-Oxobenzo[d]oxazol-3(2H)-yl)-N-((2-(thiophen-2-yl)pyridin-4-yl)methyl)acetamide2034346-53-5C19H15N3O3S
- 4(3H)-Quinazolinone, 2-((4-methoxyphenyl)methoxy)-3-(2-thiazolyl)-85178-71-8C19H15N3O3S
- 4-Cyano-N-[4-(3,4-dimethoxyphenyl)-1,3-thiazol-2-yl]benzamide313404-56-7C19H15N3O3S
- N-(3-Cyano-5,6-dihydro-4H-cyclopenta[b]thiophen-2-yl)-4-(2,5-dioxopyrrolidin-1-yl)benzamide313405-99-1C19H15N3O3S
- Pyrazinecarboxamide, N-(1-hydroxy-2-oxo-2-(4-(phenylthio)phenyl)ethyl)-42069-35-2C19H15N3O3S
- N'-(4,5-Dimethylbenzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carbohydrazide851980-52-4C19H15N3O3S
- N'-(4,6-Dimethylbenzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carbohydrazide851987-29-6C19H15N3O3S
- N-(5,7-Dimethylbenzo[d]thiazol-2-yl)-2-(1,3-dioxoisoindolin-2-yl)acetamide912766-46-2C19H15N3O3S
- 2-[[3-(2-Methylphenyl)-4-oxo-5H-pyrimido[5,4-b]indol-2-yl]sulfanyl]acetic acid887214-82-6C19H15N3O3S
- (2Z)-2-Cyano-3-{5-[(2-methylphenoxy)methyl]furan-2-yl}-N-(1,3-thiazol-2-yl)prop-2-enamide724781-21-9C19H15N3O3S
- N-Benzyl-N-(6-methoxybenzo[d]thiazol-2-yl)isoxazole-5-carboxamide941913-96-8C19H15N3O3S
- N-((1-Methyl-5-(thiophen-2-yl)-1H-pyrazol-3-yl)methyl)-4-oxo-4H-chromene-2-carboxamide1421530-39-3C19H15N3O3S
Frequently asked questions
What is the molar mass of C19H15N3O3S?
The molar mass of C19H15N3O3S is 365.41 g/mol, calculated from standard atomic weights for 19 carbon atoms, 15 hydrogen atoms, 3 nitrogen atoms, 3 oxygen atoms and 1 sulfur atom. The monoisotopic mass is 365.0834 Da.
How many compounds have the formula C19H15N3O3S?
CompoundList lists 151 compounds with the molecular formula C19H15N3O3S, including (3E)-3-[2-[(4-Hydroxyphenyl)(methyl)amino]-4-oxo-1,3-thiazol-5(4H)-ylidene]-5-methyl-1,3-dihydro-2H-indol-2-one, N-(Furan-2-ylmethyl)-2-(4-oxo-5-phenylthieno[2,3-d]pyrimidin-3-yl)acetamide, N'-(4,6-Dimethyl-1,3-benzothiazol-2-yl)-4-oxochromene-2-carbohydrazide. Compounds that share a formula are isomers. They contain the same atoms arranged differently, so their properties, uses and prices can be very different.
What is the degree of unsaturation of C19H15N3O3S?
C19H15N3O3S has a degree of unsaturation of 14. That is the total number of rings and pi bonds (a double bond counts as one, a triple bond as two) in any structure with this formula.