Molecular formula
C24H23N3O5
84 compounds have this formula on CompoundList.
- Molar mass
- 433.46g/mol
- Monoisotopic mass
- 433.1638Da
- Atoms
- 55
- Elements
- 4
- Rings plus double bonds
- 15
The formula C24H23N3O5 describes a molecule made of 24 carbon atoms, 23 hydrogen atoms, 3 nitrogen atoms and 5 oxygen atoms. 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 × 2466.50%12.011 × 24 = 288.264 g/mol
- H Hydrogen × 235.35%1.008 × 23 = 23.184 g/mol
- N Nitrogen × 39.69%14.007 × 3 = 42.021 g/mol
- O Oxygen × 518.45%15.999 × 5 = 79.995 g/mol
Look up another formula
Compounds with the formula C24H23N3O5
Isomers we list, best known first. Open one to see its structure, properties, safety data and suppliers.
Showing 1 to 84 of 84 compounds
Jzl-195
CAS 1210004-12-8C24H23N3O5
![3,5-Dimethyl 4-[3-(furan-2-yl)-1-phenyl-1H-pyrazol-4-yl]-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate chemical structure, C24H23N3O5, CAS 313050-08-7](/s/PPLRFVYTEQPNJM-UHFFFAOYSA-N.svg)
3,5-Dimethyl 4-[3-(furan-2-yl)-1-phenyl-1H-pyrazol-4-yl]-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate
CAS 313050-08-7C24H23N3O5
![Methyl 2-amino-4-(2-methoxyphenyl)-7-methyl-5-oxo-6-(pyridin-3-ylmethyl)-5,6-dihydro-4H-pyrano[3,2-c]pyridine-3-carboxylate chemical structure, C24H23N3O5, CAS 758702-35-1](/s/SAFPDBRESLLUKB-UHFFFAOYSA-N.svg)
Methyl 2-amino-4-(2-methoxyphenyl)-7-methyl-5-oxo-6-(pyridin-3-ylmethyl)-5,6-dihydro-4H-pyrano[3,2-c]pyridine-3-carboxylate
CAS 758702-35-1C24H23N3O5
![N-[7-(2,4-Dimethoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinazolin-2-yl]-2-methoxybenzamide chemical structure, C24H23N3O5, CAS 847365-03-1](/s/FYQTYHZBDUIZJY-UHFFFAOYSA-N.svg)
N-[7-(2,4-Dimethoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinazolin-2-yl]-2-methoxybenzamide
CAS 847365-03-1C24H23N3O5
N-(2-(5,8-Dimethoxy-2-oxo-1,2-dihydroquinolin-3-yl)ethyl)-2-(2-methyl-1H-indol-3-yl)-2-oxoacetamide
CAS 862813-58-9C24H23N3O5
![3,5-Dimethoxy-N-[7-(4-methoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinazolin-2-yl]benzamide chemical structure, C24H23N3O5, CAS 846584-09-6](/s/AEUDIVVJSRBPJW-UHFFFAOYSA-N.svg)
3,5-Dimethoxy-N-[7-(4-methoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinazolin-2-yl]benzamide
CAS 846584-09-6C24H23N3O5
![4-(1-Benzofuran-2-ylcarbonyl)-3-hydroxy-1-[2-(morpholin-4-yl)ethyl]-5-(pyridin-3-yl)-1,5-dihydro-2H-pyrrol-2-one chemical structure, C24H23N3O5, CAS 618366-04-4](/s/CXHLREDSCZVVPB-UHFFFAOYSA-N.svg)
4-(1-Benzofuran-2-ylcarbonyl)-3-hydroxy-1-[2-(morpholin-4-yl)ethyl]-5-(pyridin-3-yl)-1,5-dihydro-2H-pyrrol-2-one
CAS 618366-04-4C24H23N3O5
4-(2-((6-((3,4-Dihydroisoquinolin-2(1H)-yl)methyl)-4-oxo-4H-pyran-3-yl)oxy)acetamido)benzamide
CAS 898456-71-8C24H23N3O5
2-Methoxy-4-(2-(3-pyridinylcarbonyl)carbohydrazonoyl)phenyl 4-propoxybenzoate
CAS 765286-16-6C24H23N3O5
N'-(4-((4-Methylbenzyl)oxy)benzylidene)-2-(2-nitrophenoxy)propanohydrazide
CAS 881466-82-6C24H23N3O5
2-Hydroxypropyl nortadalafil
CAS 1353020-85-5C24H23N3O5
![2-[2-(4-Methyl-3-nitroanilino)-2-oxoethoxy]-N-(1-phenylethyl)benzamide chemical structure, C24H23N3O5, CAS 434309-91-8](/s/LBFCAZHRRLQEEU-UHFFFAOYSA-N.svg)
2-[2-(4-Methyl-3-nitroanilino)-2-oxoethoxy]-N-(1-phenylethyl)benzamide
CAS 434309-91-8C24H23N3O5
2-(1,3-Dioxooctahydro-2H-4,7-methanoisoindol-2-yl)-N-(3-nitrophenyl)-3-phenylpropanamide
CAS 1025725-19-2C24H23N3O5
![N-[5-Oxo-7-(3,4,5-trimethoxyphenyl)-5,6,7,8-tetrahydroquinazolin-2-yl]benzamide chemical structure, C24H23N3O5, CAS 525581-32-2](/s/QNNMRNJQKZRRPT-UHFFFAOYSA-N.svg)
N-[5-Oxo-7-(3,4,5-trimethoxyphenyl)-5,6,7,8-tetrahydroquinazolin-2-yl]benzamide
CAS 525581-32-2C24H23N3O5
![N-((1-(Benzofuran-2-carbonyl)piperidin-4-yl)methyl)-2-(2-oxobenzo[d]oxazol-3(2H)-yl)acetamide chemical structure, C24H23N3O5, CAS 1234976-21-6](/s/GLOBWZPXQOMIJF-UHFFFAOYSA-N.svg)
N-((1-(Benzofuran-2-carbonyl)piperidin-4-yl)methyl)-2-(2-oxobenzo[d]oxazol-3(2H)-yl)acetamide
CAS 1234976-21-6C24H23N3O5
Methyl 4-(2-((2-(furan-2-yl)-2-(indolin-1-yl)ethyl)amino)-2-oxoacetamido)benzoate
CAS 898433-06-2C24H23N3O5
![6-[(6,7-Dimethoxy-4-quinazolinyl)oxy]-N-(2-methoxyethyl)-1-naphthalenecarboxamide chemical structure, C24H23N3O5, CAS 861880-17-3](/s/PGINJTUIQUFAPP-UHFFFAOYSA-N.svg)
6-[(6,7-Dimethoxy-4-quinazolinyl)oxy]-N-(2-methoxyethyl)-1-naphthalenecarboxamide
CAS 861880-17-3C24H23N3O5
![N-(2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)-2-oxo-2-(1-(2-oxo-2-(pyrrolidin-1-yl)ethyl)-1H-indol-3-yl)acetamide chemical structure, C24H23N3O5, CAS 872854-83-6](/s/DUWQWUKKESSJKO-UHFFFAOYSA-N.svg)
N-(2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)-2-oxo-2-(1-(2-oxo-2-(pyrrolidin-1-yl)ethyl)-1H-indol-3-yl)acetamide
CAS 872854-83-6C24H23N3O5
![N-(5-Allyl-3,3-dimethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]oxazepin-8-yl)-2-(1,3-dioxoisoindolin-2-yl)acetamide chemical structure, C24H23N3O5, CAS 921525-26-0](/s/VFQZOCFFXVWOJK-UHFFFAOYSA-N.svg)
N-(5-Allyl-3,3-dimethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]oxazepin-8-yl)-2-(1,3-dioxoisoindolin-2-yl)acetamide
CAS 921525-26-0C24H23N3O5
![(E)-N-(2-(7-(Benzyloxy)-1,8-dioxo-3,4-dihydro-1H-pyrido[1,2-a]pyrazin-2(8H)-yl)ethyl)-3-(furan-2-yl)acrylamide chemical structure, C24H23N3O5, CAS 1105233-67-7](/s/JIZIBAIUTZHXMY-CMDGGOBGSA-N.svg)
(E)-N-(2-(7-(Benzyloxy)-1,8-dioxo-3,4-dihydro-1H-pyrido[1,2-a]pyrazin-2(8H)-yl)ethyl)-3-(furan-2-yl)acrylamide
CAS 1105233-67-7C24H23N3O5
![(R)-Methyl 3-(1H-benzo[d]imidazol-2-yl)-2-(5-(4-methoxyphenyl)-2-methylfuran-3-carboxamido)propanoate chemical structure, C24H23N3O5, CAS 1207725-96-9](/s/GUMFVHFOLWULTF-HXUWFJFHSA-N.svg)
(R)-Methyl 3-(1H-benzo[d]imidazol-2-yl)-2-(5-(4-methoxyphenyl)-2-methylfuran-3-carboxamido)propanoate
CAS 1207725-96-9C24H23N3O5
![N-(4,5-Dimethylisoxazol-3-yl)-2-[2-methoxy-4-(7-methoxyquinolin-4-yloxy)phenyl]acetamide chemical structure, C24H23N3O5, CAS 948571-26-4](/s/OQLVVMGCNQOROZ-UHFFFAOYSA-N.svg)
N-(4,5-Dimethylisoxazol-3-yl)-2-[2-methoxy-4-(7-methoxyquinolin-4-yloxy)phenyl]acetamide
CAS 948571-26-4C24H23N3O5
4-(Benzofuran-2-carbonyl)-3-hydroxy-1-(2-morpholinoethyl)-5-(pyridin-2-yl)-1H-pyrrol-2(5H)-one
CAS 618877-75-1C24H23N3O5
4-(Benzofuran-2-carbonyl)-3-hydroxy-1-(2-morpholinoethyl)-5-(pyridin-4-yl)-1H-pyrrol-2(5H)-one
CAS 618366-03-3C24H23N3O5
- N-[6,7-Dimethoxy-1-(4-methoxyphenyl)-3-oxo-1,4-dihydroisoquinolin-2-yl]pyridine-4-carboxamide5840-14-2C24H23N3O5
- 4-Acetamido-N-(4-benzamido-2,5-dimethoxyphenyl)benzamide724734-46-7C24H23N3O5
- 1-(3-(1H-Imidazol-1-yl)propyl)-5-(3-(allyloxy)phenyl)-4-(furan-2-carbonyl)-3-hydroxy-1H-pyrrol-2(5H)-one619273-24-4C24H23N3O5
- Methyl 4-(2-oxo-2-{1-[2-oxo-2-(pyrrolidin-1-yl)ethyl]-1H-indol-3-yl}acetamido)benzoate872854-69-8C24H23N3O5
- Methyl 2-amino-4-(4-methoxyphenyl)-7-methyl-5-oxo-6-(pyridin-3-ylmethyl)-5,6-dihydro-4H-pyrano[3,2-c]pyridine-3-carboxylate858747-10-1C24H23N3O5
- 5-(Furan-2-yl)-3-hydroxy-1-[3-(1H-imidazol-1-yl)propyl]-4-[4-(prop-2-en-1-yloxy)benzoyl]-2,5-dihydro-1H-pyrrol-2-one615271-13-1C24H23N3O5
- N-(7-(3,4-Dimethoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinazolin-2-yl)-4-methoxybenzamide775293-62-4C24H23N3O5
- N-(1,3-Benzodioxol-5-yl)-2-oxo-2-[1-(2-oxo-2-piperidin-1-ylethyl)indol-3-yl]acetamide872862-21-0C24H23N3O5
- 2-(2,4-Dioxo-3-(p-tolyl)-3,4-dihydrobenzofuro[3,2-d]pyrimidin-1(2H)-yl)-N-((tetrahydrofuran-2-yl)methyl)acetamide877657-24-4C24H23N3O5
- N-(3-Acetylphenyl)-2-(1-(2-morpholino-2-oxoethyl)-1H-indol-3-yl)-2-oxoacetamide872857-35-7C24H23N3O5
- N-(2,5-Dimethoxyphenyl)-N'-[(E)-(4-phenylmethoxyphenyl)methylideneamino]oxamide352014-03-0C24H23N3O5
- 1H-Pyrido(3,4-b)indol-6-ol, 2,3,4,9-tetrahydro-1-(3-indolylmethyl)-, (E)-2-butenedioate (1:1)61326-53-2C24H23N3O5
- N-{[3-(3,4-Dimethoxyphenyl)-1,2,4-oxadiazol-5-yl]methyl}-N-methyl-2-(naphthalen-2-yloxy)acetamide887694-91-9C24H23N3O5
- N-{[3-(3,4-Dimethoxyphenyl)-1,2,4-oxadiazol-5-yl]methyl}-N-methyl-2-(naphthalen-1-yloxy)acetamide887694-97-5C24H23N3O5
- Benzoic acid, p-(p-methoxybenzamido)-, 2-veratrylidenehydrazide100278-37-3C24H23N3O5
- N-[2-(1H-Indol-3-yl)ethyl]-N~2~-{[(4-methyl-2-oxo-2H-chromen-7-yl)oxy]acetyl}glycinamide1010877-09-4C24H23N3O5
- 3-(7-Methoxy-4-methyl-2-oxo-2H-chromen-6-yl)-N-(2-(3-phenyl-1,2,4-oxadiazol-5-yl)ethyl)propanamide1010900-89-6C24H23N3O5
- 1-(2,3-Dihydro-1,4-benzodioxin-6-yl)-3-(6-methoxy-1,3,4,9-tetrahydro-2H-beta-carbolin-2-yl)pyrrolidine-2,5-dione1144480-94-3C24H23N3O5
- 1-(3,4-Dimethoxyphenyl)-3-{9-ethyl-10-oxo-2-oxa-9-azatricyclo[9.4.0.0^{3,8}]pentadeca-1(11),3(8),4,6,12,14-hexaen-13-yl}urea1203080-58-3C24H23N3O5
- 1-(2,3-Dimethoxyphenyl)-3-{6,9-dimethyl-10-oxo-2-oxa-9-azatricyclo[9.4.0.0^{3,8}]pentadeca-1(11),3(8),4,6,12,14-hexaen-13-yl}urea1203359-26-5C24H23N3O5
- 2-[(4-Methyl-2-oxo-2H-chromen-7-yl)oxy]-N-[3-(2-methylpropyl)-4-oxo-3,4-dihydroquinazolin-6-yl]acetamide1574477-32-9C24H23N3O5
- Ethyl 4-(5-(4-methoxyphenyl)-1,3-dimethyl-2,4-dioxo-3,4-dihydro-1H-pyrrolo[3,4-d]pyrimidin-6(2H)-yl)benzoate682347-13-3C24H23N3O5
- N-(4-Acetylphenyl)-2-(1-(2-morpholino-2-oxoethyl)-1H-indol-3-yl)-2-oxoacetamide872857-34-6C24H23N3O5
- N-(Benzo[d][1,3]dioxol-5-ylmethyl)-2-oxo-2-(1-(2-oxo-2-(pyrrolidin-1-yl)ethyl)-1H-indol-3-yl)acetamide872849-11-1C24H23N3O5
- 1-({3-[(10aS)-1,3-Dioxo-1,5,10,10a-tetrahydroimidazo[1,5-b]isoquinolin-2(3H)-yl]phenyl}carbonyl)piperidine-4-carboxylic acid1014024-36-2C24H23N3O5
- N1-(benzo[d][1,3]dioxol-5-ylmethyl)-N2-(2-(furan-2-yl)-2-(indolin-1-yl)ethyl)oxalamide898416-34-7C24H23N3O5
- N1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-N2-(2-(furan-2-yl)-2-(indolin-1-yl)ethyl)oxalamide898416-47-2C24H23N3O5
- N1-(benzo[d][1,3]dioxol-5-yl)-N2-(2-(3,4-dihydroisoquinolin-2(1H)-yl)-2-(furan-2-yl)ethyl)oxalamide898416-91-6C24H23N3O5
- N-(2,4-Dimethoxyphenyl)-2-(7-ethoxy-5-oxobenzo[b][1,8]naphthyridin-10(5H)-yl)acetamide894547-06-9C24H23N3O5
- Methyl 4-[({[9-oxo-8-(prop-2-en-1-yl)-1,2,3,9-tetrahydropyrrolo[2,1-b]quinazolin-7-yl]oxy}acetyl)amino]benzoate1071914-97-0C24H23N3O5
- N-(5-Allyl-3,3-dimethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]oxazepin-7-yl)-2-(1,3-dioxoisoindolin-2-yl)acetamide921864-08-6C24H23N3O5
- N-[3-(1H-Imidazol-1-yl)propyl]-2-[4-(8-methoxy-2-oxo-2H-chromen-3-yl)phenoxy]acetamide1010884-24-8C24H23N3O5
- 2-[2-(1-Acetyl-2,3-dihydro-1H-indol-5-yl)-2-oxoethyl]-6-(3,4-dimethoxyphenyl)pyridazin-3(2H)-one1219571-40-0C24H23N3O5
- 4-Hydroxy-N-(4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-2-oxo-1-pentyl-1,2-dihydroquinoline-3-carboxamide300388-17-4C24H23N3O5
- 4-[2-(Furan-2-yl)-6-methylpyridin-3-yloxy]-N-(3,4,5-trimethoxy-phenyl)pyridin-2-amine1117685-80-9C24H23N3O5
- 1 suppliers1-(6,11-Dihydrodibenzo[b,e]oxepin-11-yl)-5-hydroxy-3-(2-methoxyethyl)-2,3-dihydro-1H-pyrido[2,1-f][1,2,4]triazine-4,6-dione1370241-26-1C24H23N3O5
- N-((1-(Benzo[d]oxazol-2-yl)piperidin-4-yl)methyl)-8-methoxy-2-oxo-2H-chromene-3-carboxamide1797955-67-9C24H23N3O5
- 2-(1-(4-Methoxy-6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl)azetidin-3-yl)-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-dione1904074-84-5C24H23N3O5
- 1-(1-(7-Methoxybenzofuran-2-carbonyl)piperidin-4-yl)-3-phenylimidazolidine-2,4-dione1904187-58-1C24H23N3O5
- 3-(1-Ethyl-4-hydroxy-2-oxo-1,2-dihydro-3-quinolinyl)-N-(2-furylmethyl)-3-[(2-furylmethyl)imino]propanamide882747-58-2C24H23N3O5
- N-[4-[4-(Furan-2-carbonyl)piperazin-1-yl]phenyl]-2,3-dihydro-1,4-benzodioxine-6-carboxamide876886-31-6C24H23N3O5
- 1-(3,5-Dimethoxybenzyl)-3-(4-methoxybenzyl)pyrido[3,2-d]pyrimidine-2,4(1H,3H)-dione921774-92-7C24H23N3O5
- N'-((E)-{4-[(4-Methylbenzyl)oxy]phenyl}methylidene)-2-(4-nitrophenoxy)propanohydrazide767339-00-4C24H23N3O5
- N'-{2-[4-(Furan-2-yl)phenyl]-2-hydroxyethyl}-N-[3-(2-oxopyrrolidin-1-yl)phenyl]ethanediamide2097916-75-9C24H23N3O5
- Hydroxypropyl nortadalafil2520114-73-0C24H23N3O5
- 3-[(2-Hydroxy-6,7,8,9-tetrahydrodibenzofuran-1-yl)methylideneamino]-6,7-dimethoxy-2-methylquinazolin-4-one587009-06-1C24H23N3O5
- N-[(E)-3-(Butylamino)-1-[5-(4-nitrophenyl)furan-2-yl]-3-oxoprop-1-en-2-yl]benzamide302603-22-1C24H23N3O5
- 2-Ethoxy-4-{(E)-[(3-pyridinylcarbonyl)hydrazono]methyl}phenyl 4-ethoxybenzoate767301-94-0C24H23N3O5
- 4-({[(9H-Fluoren-9-yl)methoxy]carbonyl}amino)-4-[(1H-pyrrol-1-yl)carbamoyl]butanoic acid2171743-15-8C24H23N3O5
- 3-{3-[1-({[(9H-Fluoren-9-yl)methoxy]carbonyl}amino)cyclobutyl]-1,2,4-oxadiazol-5-yl}propanoic acid2172375-89-0C24H23N3O5
- 4-(3-Cyanopyrrolidin-1-yl)-3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-oxobutanoic acid2171782-82-2C24H23N3O5
- 3-({[(9H-Fluoren-9-yl)methoxy]carbonyl}amino)-3-{[(1H-pyrrol-3-yl)methyl]carbamoyl}propanoic acid2171599-19-0C24H23N3O5
- 2-[2-({[(9H-Fluoren-9-yl)methoxy]carbonyl}amino)-3-(1H-pyrrol-2-yl)propanamido]acetic acid2171651-19-5C24H23N3O5
- 5-({[(9H-Fluoren-9-yl)methoxy]carbonyl}amino)-1-(oxan-4-yl)-1H-pyrazole-4-carboxylic acid2580222-59-7C24H23N3O5
- 3-(tert-Butoxy)-6-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)pyrazine-2-carboxylic acid2580243-91-8C24H23N3O5
- 2-[4-({[(9H-Fluoren-9-yl)methoxy]carbonyl}amino)oxan-4-yl]-1H-imidazole-4-carboxylic acid2763998-41-8C24H23N3O5
- ((1-Benzhydryl-3-methyl-4,6-dioxo-2,3,4,6-tetrahydro-1H-pyrido[2,1-f][1,2,4]triazin-5-yl)oxy)methyl acetate1369552-87-3C24H23N3O5
- (10S,23R)-23-Amino-10-ethyl-10-hydroxy-19-methoxy-8-oxa-4,15-diazahexacyclo[14.7.1.02,14.04,13.06,11.020,24]tetracosa-1,6(11),12,14,16(24),17,19-heptaene-5,9-dione143728-88-5C24H23N3O5
- (10S,23S)-23-Amino-10-ethyl-10-hydroxy-19-methoxy-8-oxa-4,15-diazahexacyclo[14.7.1.02,14.04,13.06,11.020,24]tetracosa-1,6(11),12,14,16(24),17,19-heptaene-5,9-dione143655-67-8C24H23N3O5
- 2-(1,3-Benzodioxol-5-yl)-6-(3-hydroxypropyl)-3,6,17-triazatetracyclo[8.7.0.03,8.011,16]heptadeca-1(10),11,13,15-tetraene-4,7-dione2237219-65-5C24H23N3O5
Frequently asked questions
What is the molar mass of C24H23N3O5?
The molar mass of C24H23N3O5 is 433.46 g/mol, calculated from standard atomic weights for 24 carbon atoms, 23 hydrogen atoms, 3 nitrogen atoms and 5 oxygen atoms. The monoisotopic mass is 433.1638 Da.
How many compounds have the formula C24H23N3O5?
CompoundList lists 84 compounds with the molecular formula C24H23N3O5, including Jzl-195, 3,5-Dimethyl 4-[3-(furan-2-yl)-1-phenyl-1H-pyrazol-4-yl]-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate, Methyl 2-amino-4-(2-methoxyphenyl)-7-methyl-5-oxo-6-(pyridin-3-ylmethyl)-5,6-dihydro-4H-pyrano[3,2-c]pyridine-3-carboxylate. 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 C24H23N3O5?
C24H23N3O5 has a degree of unsaturation of 15. 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.