Molecular formula
C21H20N2O4S
199 compounds have this formula on CompoundList.
- Molar mass
- 396.46g/mol
- Monoisotopic mass
- 396.1144Da
- Atoms
- 48
- Elements
- 5
- Rings plus double bonds
- 13
The formula C21H20N2O4S describes a molecule made of 21 carbon atoms, 20 hydrogen atoms, 2 nitrogen atoms, 4 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 × 2163.62%12.011 × 21 = 252.231 g/mol
- H Hydrogen × 205.08%1.008 × 20 = 20.160 g/mol
- N Nitrogen × 27.07%14.007 × 2 = 28.014 g/mol
- O Oxygen × 416.14%15.999 × 4 = 63.996 g/mol
- S Sulfur × 18.09%32.06 × 1 = 32.060 g/mol
Look up another formula
Compounds with the formula C21H20N2O4S
Isomers we list, best known first. Open one to see its structure, properties, safety data and suppliers.
Showing 101 to 199 of 199 compounds
![2-Methoxy-N-[4-[(3-methylphenyl)sulfamoyl]phenyl]benzamide chemical structure, C21H20N2O4S, CAS 694485-84-2](/s/CQZIRWZVUQCUMD-UHFFFAOYSA-N.svg)
2-Methoxy-N-[4-[(3-methylphenyl)sulfamoyl]phenyl]benzamide
CAS 694485-84-2C21H20N2O4S
![2-[(5Z)-5-(2-Ethoxybenzylidene)-2,4-dioxo-1,3-thiazolidin-3-yl]-N-(4-methylphenyl)acetamide chemical structure, C21H20N2O4S, CAS 431979-23-6](/s/XHLYJKSMWNRKDS-PDGQHHTCSA-N.svg)
2-[(5Z)-5-(2-Ethoxybenzylidene)-2,4-dioxo-1,3-thiazolidin-3-yl]-N-(4-methylphenyl)acetamide
CAS 431979-23-6C21H20N2O4S
4-(Dimethylsulfamoyl)-N-(2-phenoxyphenyl)benzamide
CAS 313404-17-0C21H20N2O4S
![Propyl 4-({[(3-methyl-1-benzofuran-2-yl)carbonyl]carbamothioyl}amino)benzoate chemical structure, C21H20N2O4S, CAS 428852-91-9](/s/AYTITSSCDIIVJO-UHFFFAOYSA-N.svg)
Propyl 4-({[(3-methyl-1-benzofuran-2-yl)carbonyl]carbamothioyl}amino)benzoate
CAS 428852-91-9C21H20N2O4S
2-(Methanesulfonamido)-N-(4-phenylmethoxyphenyl)benzamide
CAS 825655-50-3C21H20N2O4S
![N-[4-Methoxy-2-[[2-(4-methylphenyl)sulfanylacetyl]amino]phenyl]furan-2-carboxamide chemical structure, C21H20N2O4S, CAS 831234-86-7](/s/XMZYFVBDMPNTQY-UHFFFAOYSA-N.svg)
N-[4-Methoxy-2-[[2-(4-methylphenyl)sulfanylacetyl]amino]phenyl]furan-2-carboxamide
CAS 831234-86-7C21H20N2O4S
![N-[4-(4-Propoxyphenyl)-1,3-thiazol-2-yl]-2,3-dihydro-1,4-benzodioxine-6-carboxamide chemical structure, C21H20N2O4S, CAS 477550-70-2](/s/TYNSNCXDRHHMPW-UHFFFAOYSA-N.svg)
N-[4-(4-Propoxyphenyl)-1,3-thiazol-2-yl]-2,3-dihydro-1,4-benzodioxine-6-carboxamide
CAS 477550-70-2C21H20N2O4S
N-(3-Carbamoyl-4,5,6,7-tetrahydro-1-benzothiophen-2-yl)-6-ethyl-4-oxo-4H-chromene-2-carboxamide
CAS 874356-14-6C21H20N2O4S
![N-[3-(Ethylcarbamoyl)-4,5,6,7-tetrahydro-1-benzothiophen-2-yl]-4-oxo-4H-chromene-2-carboxamide chemical structure, C21H20N2O4S, CAS 881218-34-4](/s/LUICJGQAHQMISC-UHFFFAOYSA-N.svg)
N-[3-(Ethylcarbamoyl)-4,5,6,7-tetrahydro-1-benzothiophen-2-yl]-4-oxo-4H-chromene-2-carboxamide
CAS 881218-34-4C21H20N2O4S
![3-Methyl-2-thioxo-4-(3,4,5-trimethoxyphenyl)-1,2,3,4-tetrahydro-5H-indeno[1,2-d]pyrimidin-5-one chemical structure, C21H20N2O4S, CAS 685106-54-1](/s/INTJRXBMPAHYKL-UHFFFAOYSA-N.svg)
3-Methyl-2-thioxo-4-(3,4,5-trimethoxyphenyl)-1,2,3,4-tetrahydro-5H-indeno[1,2-d]pyrimidin-5-one
CAS 685106-54-1C21H20N2O4S
![1-[8-(Benzenesulfonyl)-2H,3H-[1,4]dioxino[2,3-g]quinolin-9-yl]pyrrolidine chemical structure, C21H20N2O4S, CAS 866811-89-4](/s/IHEWCDFKRLUYBX-UHFFFAOYSA-N.svg)
1-[8-(Benzenesulfonyl)-2H,3H-[1,4]dioxino[2,3-g]quinolin-9-yl]pyrrolidine
CAS 866811-89-4C21H20N2O4S
![3-[(5Z)-5-Benzylidene-2,4-dioxo-1,3-thiazolidin-3-yl]-N-[2-(4-hydroxyphenyl)ethyl]propanamide chemical structure, C21H20N2O4S, CAS 902026-30-6](/s/QTWPJXIUEGFLRI-JXAWBTAJSA-N.svg)
3-[(5Z)-5-Benzylidene-2,4-dioxo-1,3-thiazolidin-3-yl]-N-[2-(4-hydroxyphenyl)ethyl]propanamide
CAS 902026-30-6C21H20N2O4S
![N-[3-(Methylcarbamoyl)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-2-yl]-2-oxochromene-3-carboxamide chemical structure, C21H20N2O4S, CAS 893126-49-3](/s/XMJGXCAUULBDOX-UHFFFAOYSA-N.svg)
N-[3-(Methylcarbamoyl)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-2-yl]-2-oxochromene-3-carboxamide
CAS 893126-49-3C21H20N2O4S
![Ethyl 2-[2-(4-methoxyphenyl)acetamido]-4-phenyl-1,3-thiazole-5-carboxylate chemical structure, C21H20N2O4S, CAS 923415-29-6](/s/YTOLIORMDYPSRC-UHFFFAOYSA-N.svg)
Ethyl 2-[2-(4-methoxyphenyl)acetamido]-4-phenyl-1,3-thiazole-5-carboxylate
CAS 923415-29-6C21H20N2O4S
![3-(4-Methoxyphenyl)-5-methyl-1'-propanoylspiro[1,3-thiazolidine-2,3'-indole]-2',4-dione chemical structure, C21H20N2O4S, CAS 924822-26-4](/s/VZOGFZSAEXTPTQ-UHFFFAOYSA-N.svg)
3-(4-Methoxyphenyl)-5-methyl-1'-propanoylspiro[1,3-thiazolidine-2,3'-indole]-2',4-dione
CAS 924822-26-4C21H20N2O4S
3-Methoxy-N-(2-(phenylsulfonyl)-2-(pyridin-3-yl)ethyl)benzamide
CAS 892316-91-5C21H20N2O4S
6-((4-Methoxyphenyl)amino)-8-(phenylsulfonyl)-2,3-dihydroindolizin-5(1H)-one
CAS 612065-25-5C21H20N2O4S
3-((2-(3,4-Dimethoxyphenyl)-2-oxoethyl)thio)-1-(p-tolyl)pyrazin-2(1H)-one
CAS 946293-49-8C21H20N2O4S
7beta-Amino-3-methoxy-3-cephem-4-carboxylic acid diphenylmethyl ester
CAS 51761-98-9C21H20N2O4S
![(4-(Benzo[d]thiazol-2-yloxy)piperidin-1-yl)(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)methanone chemical structure, C21H20N2O4S, CAS 1251564-99-4](/s/MZLJFATZOHNMPZ-UHFFFAOYSA-N.svg)
(4-(Benzo[d]thiazol-2-yloxy)piperidin-1-yl)(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)methanone
CAS 1251564-99-4C21H20N2O4S
1-((3,4-Dimethoxyphenyl)sulfonyl)-5-(pyridin-4-yl)indoline
CAS 2034376-14-0C21H20N2O4S
N-(3-Carbamoyl-4,5,6,7-tetrahydro-1-benzothiophen-2-yl)-6,8-dimethyl-4-oxo-4H-chromene-2-carboxamide
CAS 898469-27-7C21H20N2O4S
![7-Methyl-2-(2,3,4-trimethoxyphenyl)-1,5-dihydrochromeno[2,3-d]pyrimidine-4-thione chemical structure, C21H20N2O4S, CAS 866808-01-7](/s/OEBSSURXNNVJRC-UHFFFAOYSA-N.svg)
7-Methyl-2-(2,3,4-trimethoxyphenyl)-1,5-dihydrochromeno[2,3-d]pyrimidine-4-thione
CAS 866808-01-7C21H20N2O4S
N-(4-Ethoxy-3-prop-2-ynyl-1,3-benzothiazol-2-ylidene)-3,5-dimethoxybenzamide
CAS 868377-13-3C21H20N2O4S
- 3,4,5-Trimethoxy-N-(4-methyl-3-prop-2-ynyl-1,3-benzothiazol-2-ylidene)benzamide868377-25-7C21H20N2O4S
- N-(4-Ethoxy-3-prop-2-ynyl-1,3-benzothiazol-2-ylidene)-3,4-dimethoxybenzamide868377-72-4C21H20N2O4S
- (5E)-5-[(3,4-Dimethoxyphenyl)methylidene]-1-methyl-3-(4-methylphenyl)-2-sulfanylidene-1,3-diazinane-4,6-dione6078-82-6C21H20N2O4S
- N-(3,4-Dimethylphenyl)-2-[(5E)-5-(3-methoxybenzylidene)-2,4-dioxo-1,3-thiazolidin-3-yl]acetamide431939-35-4C21H20N2O4S
- Butyl 4-{[(1-benzofuran-2-ylcarbonyl)carbamothioyl]amino}benzoate428503-04-2C21H20N2O4S
- Ethyl 2-{[2-(1,3-benzoxazol-2-yl)-3-oxo-1-propenyl]amino}-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate392732-31-9C21H20N2O4S
- N-(6-Ethoxy-3-prop-2-ynyl-1,3-benzothiazol-2-ylidene)-3,4-dimethoxybenzamide942011-95-2C21H20N2O4S
- (Z)-3,4,5-Trimethoxy-N-(6-methyl-3-(prop-2-yn-1-yl)benzo[d]thiazol-2(3H)-ylidene)benzamide942011-68-9C21H20N2O4S
- (Z)-N-(6-Ethoxy-3-(prop-2-yn-1-yl)benzo[d]thiazol-2(3H)-ylidene)-2,4-dimethoxybenzamide865197-14-4C21H20N2O4S
- N-(3-Carbamoyl-4,5,6,7-tetrahydro-1-benzothiophen-2-yl)-7,8-dimethyl-4-oxo-4H-chromene-2-carboxamide874399-28-7C21H20N2O4S
- 7-Methyl-N-[3-(methylcarbamoyl)-4,5,6,7-tetrahydro-1-benzothiophen-2-yl]-4-oxo-4H-chromene-2-carboxamide873081-25-5C21H20N2O4S
- (5E)-5-(4-Hydroxy-3-methoxybenzylidene)-1-[4-(propan-2-yl)phenyl]-2-thioxodihydropyrimidine-4,6(1H,5H)-dione340308-63-6C21H20N2O4S
- N-(4-Ethoxy-3-prop-2-ynyl-1,3-benzothiazol-2-ylidene)-2,6-dimethoxybenzamide868674-81-1C21H20N2O4S
- N-(3-(1,1-Dioxidoisothiazolidin-2-yl)phenyl)-2-(naphthalen-2-yloxy)acetamide941985-94-0C21H20N2O4S
- N-(5-(1,1-Dioxidoisothiazolidin-2-yl)-2-methoxyphenyl)-1-naphthamide941986-00-1C21H20N2O4S
- N-(5-(1,1-Dioxidoisothiazolidin-2-yl)-2-methoxyphenyl)-2-naphthamide941899-62-3C21H20N2O4S
- N-(1-(Furan-2-carbonyl)-1,2,3,4-tetrahydroquinolin-6-yl)-3-methylbenzenesulfonamide946258-13-5C21H20N2O4S
- N-(1-(Furan-2-carbonyl)-1,2,3,4-tetrahydroquinolin-7-yl)-3-methylbenzenesulfonamide946220-20-8C21H20N2O4S
- N-(1-(Furan-2-carbonyl)-1,2,3,4-tetrahydroquinolin-7-yl)-4-methylbenzenesulfonamide946267-50-1C21H20N2O4S
- N-(1-Tosyl-1,2,3,4-tetrahydroquinolin-7-yl)furan-2-carboxamide898447-76-2C21H20N2O4S
- N-Benzyl-N-(4-ethoxybenzo[d]thiazol-2-yl)-5,6-dihydro-1,4-dioxine-2-carboxamide922849-42-1C21H20N2O4S
- Ethyl 2-methyl-5-(2-oxo-2-((thiophen-2-ylmethyl)amino)acetyl)-4-phenyl-1H-pyrrole-3-carboxylate1004172-47-7C21H20N2O4S
- N-[3-Methoxy-4-(2-oxopyrrolidin-1-yl)phenyl]naphthalene-2-sulfonamide941958-50-5C21H20N2O4S
- N-(1-Tosyl-1,2,3,4-tetrahydroquinolin-6-yl)furan-2-carboxamide899983-52-9C21H20N2O4S
- Methyl (2-(piperidin-1-yl)benzo[d]thiazol-6-yl) terephthalate941890-51-3C21H20N2O4S
- N-(3,4-Dihydro-2H-1,5-benzodioxepin-7-yl)-2-[2-(4-methoxyphenyl)-1,3-thiazol-4-yl]acetamide877981-02-7C21H20N2O4S
- N-(2-(Furan-2-carbonyl)-1,2,3,4-tetrahydroisoquinolin-7-yl)-4-methylbenzenesulfonamide955722-96-0C21H20N2O4S
- N-(2-(Furan-2-carbonyl)-1,2,3,4-tetrahydroisoquinolin-7-yl)-3-methylbenzenesulfonamide955649-78-2C21H20N2O4S
- (Z)-4-Acetyl-N-(3-allyl-5,6-dimethoxybenzo[d]thiazol-2(3H)-ylidene)benzamide895455-12-6C21H20N2O4S
- Methyl 2-((2-((2,4-dimethylphenyl)amino)-2-oxoethyl)thio)-4-oxo-1,4-dihydroquinoline-3-carboxylate951497-20-4C21H20N2O4S
- Methyl 2-[({[(4-methylphenyl)methyl]carbamoyl}methyl)sulfanyl]-4-oxo-1,4-dihydroquinoline-3-carboxylate951510-43-3C21H20N2O4S
- N-(3,4-Dihydro-2H-1,5-benzodioxepin-7-yl)-2-(4-methoxyphenyl)-4-methyl-1,3-thiazole-5-carboxamide1351689-81-0C21H20N2O4S
- N-(3,3-Dimethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]oxazepin-8-yl)naphthalene-1-sulfonamide922051-30-7C21H20N2O4S
- N-(3,3-Dimethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]oxazepin-7-yl)naphthalene-2-sulfonamide922004-62-4C21H20N2O4S
- N-(6-Methyl-3-(methylcarbamoyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-2-oxo-2H-chromene-3-carboxamide892978-98-2C21H20N2O4S
- Methyl 4-(4-(benzo[d]thiazol-2-yloxy)piperidine-1-carbonyl)benzoate1286704-16-2C21H20N2O4S
- Methyl 6-methyl-4-({[3-(methylsulfanyl)phenyl]carbamoyl}methoxy)quinoline-2-carboxylate1358223-46-7C21H20N2O4S
- N-(3,4-Dihydro-2H-1,5-benzodioxepin-7-yl)-2-(3-methoxyphenyl)-4-methyl-1,3-thiazole-5-carboxamide1351682-45-5C21H20N2O4S
- N-[5-Methoxy-2-(2-oxopyrrolidin-1-yl)phenyl]naphthalene-2-sulfonamide1374519-44-4C21H20N2O4S
- N1-((5-(hydroxy(phenyl)methyl)thiophen-2-yl)methyl)-N2-(2-methoxyphenyl)oxalamide1797143-00-0C21H20N2O4S
- N-Cyclopropyl-N-[1-(2-naphthyl)ethyl]-2-nitrobenzenesulfonamide1399849-39-8C21H20N2O4S
- (4-(1H-Pyrrol-1-yl)phenyl)(3-((4-methoxyphenyl)sulfonyl)azetidin-1-yl)methanone1706164-17-1C21H20N2O4S
- 1-(3-((3-(Quinolin-8-yloxy)pyrrolidin-1-yl)sulfonyl)phenyl)ethanone1903172-31-5C21H20N2O4S
- N-(1-(Benzofuran-2-yl)propan-2-yl)-4-(2-methyloxazol-4-yl)benzenesulfonamide2034611-49-7C21H20N2O4S
- N-(2-{[(5-Methoxy-6-oxocyclohexa-2,4-dien-1-ylidene)methyl]amino}phenyl)-4-methylbenzene-1-sulfonamide28857-00-3C21H20N2O4S
- N-[(2,4-Dimethoxyphenyl)carbamothioyl]-3-methoxynaphthalene-2-carboxamide371221-76-0C21H20N2O4S
- 3-{[(2E,5Z)-5-(2-Ethoxybenzylidene)-3-ethyl-4-oxo-1,3-thiazolidin-2-ylidene]amino}benzoic acid675168-68-0C21H20N2O4S
- 2-[5-(4-Methoxy-3-methylbenzylidene)-2,4-dioxo-1,3-thiazolidin-3-yl]-N-(4-methylphenyl)acetamide431895-42-0C21H20N2O4S
- 2-[4-[(E)-(3-Ethyl-2,4-dioxo-1,3-thiazolidin-5-ylidene)methyl]phenoxy]-N-(4-methylphenyl)acetamide593274-14-7C21H20N2O4S
- 5-[[4-[2-(2,5-Dimethylphenoxy)ethoxy]phenyl]methylidene]-2-sulfanylidene-1,3-diazinane-4,6-dione6378-40-1C21H20N2O4S
- 4-(Benzenesulfonamido)-N-[(2-methoxyphenyl)methyl]benzamide838843-07-5C21H20N2O4S
- N-[2-(2,5-Dimethyl-1H-indol-3-yl)ethyl]-2-oxo-2H-chromene-6-sulfonamide728024-97-3C21H20N2O4S
- N-[4-Methoxy-3-(2-oxopyrrolidin-1-yl)phenyl]naphthalene-2-sulfonamide941978-15-0C21H20N2O4S
- N-[4-Methoxy-3-(2-oxopyrrolidin-1-yl)phenyl]naphthalene-1-sulfonamide941918-36-1C21H20N2O4S
- 2-{N-[(Furan-2-yl)methyl]-2-phenylethenesulfonamido}-N-phenylacetamide871662-77-0C21H20N2O4S
- 1-(4-Methylphenyl)-1-oxopropan-2-yl 2-(furan-2-yl)-4-methyl-6-(methylsulfanyl)pyrimidine-5-carboxylate949442-90-4C21H20N2O4S
- 4-({N-[(Furan-2-yl)methyl]-2-phenylethenesulfonamido}methyl)benzamide1011064-16-6C21H20N2O4S
- N-Benzyl-2-nitro-N-(2-phenylethyl)benzene-1-sulfonamide914077-33-1C21H20N2O4S
- N'-{2-[4-(Furan-2-yl)phenyl]-2-hydroxyethyl}-N-[2-(methylsulfanyl)phenyl]ethanediamide2097914-33-3C21H20N2O4S
- Acridine, 9-(m-anisidino)-, methanesulfonate75775-68-7C21H20N2O4S
- 2-Propenamide, 3-(4-(acetyloxy)-3-ethoxy-5-((phenylthio)methyl)phenyl)-2-cyano-107788-05-6C21H20N2O4S
- N-{2-Hydroxy-2-[4-(thiophen-2-yl)phenyl]ethyl}-N'-(4-methoxyphenyl)ethanediamide2380184-57-4C21H20N2O4S
- Methyl 6-benzyl-2-(furan-2-carboxamido)-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate524681-84-3C21H20N2O4S
- [6-(Biphenyl-4-sulfonylamino)-pyridin-2-yl]acetic acid ethyl ester887149-40-8C21H20N2O4S
- 1,3-Dioxo-2,3-dihydro-1H-isoindol-2-yl 2-[(cyclohexylmethyl)sulfanyl]pyridine-3-carboxylate2248340-48-7C21H20N2O4S
- 4-{4-[(Benzyloxy)carbonyl]piperazin-1-yl}-1-benzothiophene-2-carboxylic acid2019119-48-1C21H20N2O4S
- 2-(2-{[(Benzyloxy)carbonyl]amino}-4-(3,4-dimethylphenyl)-1,3-thiazol-5-yl)acetic acid2639456-00-9C21H20N2O4S
- 4-{[(Benzyloxy)carbonyl](4-phenyl-1,3-thiazol-2-yl)amino}butanoic acid2680676-02-0C21H20N2O4S
- 2-{[(Benzyloxy)carbonyl](2-phenylethyl)amino}-4-methyl-1,3-thiazole-5-carboxylic acid2680665-07-8C21H20N2O4S
- 4-{[(Benzyloxy)carbonyl][2-(4-methyl-1,3-thiazol-2-yl)ethyl]amino}benzoic acid2680902-34-3C21H20N2O4S
- 2-{[(Benzyloxy)carbonyl](2-phenylethyl)amino}-5-methyl-1,3-thiazole-4-carboxylic acid2680809-38-3C21H20N2O4S
- 2-(Benzyloxy)-5-(1-(cyclopropylsulfonyl)-1H-pyrazol-4-yl)-3-methylbenzaldehyde3078553-01-9C21H20N2O4S
- (4S,5R)-3-((S)-3-Hydroxy-3-(2-methylbenzo[d]thiazol-5-yl)propanoyl)-4-methyl-5-phenyloxazolidin-2-one924727-12-8C21H20N2O4S
- 4-[6-(1,3-Dioxoisoindol-2-yl)hexylsulfonyl]benzonitrile2816914-57-3C21H20N2O4S
- tert-Butyl 3-hydroxy-2-[3-(thiophene-2-carbonylimino)isoindol-1-yl]but-2-enoate786680-74-8C21H20N2O4S
Frequently asked questions
What is the molar mass of C21H20N2O4S?
The molar mass of C21H20N2O4S is 396.46 g/mol, calculated from standard atomic weights for 21 carbon atoms, 20 hydrogen atoms, 2 nitrogen atoms, 4 oxygen atoms and 1 sulfur atom. The monoisotopic mass is 396.1144 Da.
How many compounds have the formula C21H20N2O4S?
CompoundList lists 199 compounds with the molecular formula C21H20N2O4S, including 2-Methoxy-N-[4-[(3-methylphenyl)sulfamoyl]phenyl]benzamide, 2-[(5Z)-5-(2-Ethoxybenzylidene)-2,4-dioxo-1,3-thiazolidin-3-yl]-N-(4-methylphenyl)acetamide, 4-(Dimethylsulfamoyl)-N-(2-phenoxyphenyl)benzamide. 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 C21H20N2O4S?
C21H20N2O4S has a degree of unsaturation of 13. 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.