Molecular formula
C16H18N4O4S
111 compounds have this formula on CompoundList.
- Molar mass
- 362.40g/mol
- Monoisotopic mass
- 362.1049Da
- Atoms
- 43
- Elements
- 5
- Rings plus double bonds
- 10
The formula C16H18N4O4S describes a molecule made of 16 carbon atoms, 18 hydrogen atoms, 4 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 × 1653.03%12.011 × 16 = 192.176 g/mol
- H Hydrogen × 185.01%1.008 × 18 = 18.144 g/mol
- N Nitrogen × 415.46%14.007 × 4 = 56.028 g/mol
- O Oxygen × 417.66%15.999 × 4 = 63.996 g/mol
- S Sulfur × 18.85%32.06 × 1 = 32.060 g/mol
Look up another formula
Compounds with the formula C16H18N4O4S
Isomers we list, best known first. Open one to see its structure, properties, safety data and suppliers.
Showing 1 to 100 of 111 compounds
![5-(Furan-2-yl(1,4-dioxa-8-azaspiro[4.5]decan-8-yl)methyl)thiazolo[3,2-b][1,2,4]triazol-6-ol chemical structure, C16H18N4O4S, CAS 868220-76-2](/s/JRAVLTMEUUWOEH-UHFFFAOYSA-N.svg)
5-(Furan-2-yl(1,4-dioxa-8-azaspiro[4.5]decan-8-yl)methyl)thiazolo[3,2-b][1,2,4]triazol-6-ol
CAS 868220-76-2C16H18N4O4S
N-((5-((2-Morpholino-2-oxoethyl)thio)-1,3,4-oxadiazol-2-yl)methyl)benzamide
CAS 872613-45-1C16H18N4O4S
![1-[(4-Methylphenyl)sulfonyl]-4-(5-nitro-2-pyridinyl)piperazine chemical structure, C16H18N4O4S, CAS 219689-78-8](/s/APJJCBYZGGBCRU-UHFFFAOYSA-N.svg)
1-[(4-Methylphenyl)sulfonyl]-4-(5-nitro-2-pyridinyl)piperazine
CAS 219689-78-8C16H18N4O4S
![4-[(1,3-Dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-N,N,3,5-tetramethyl-1H-pyrazole-1-sulfonamide chemical structure, C16H18N4O4S, CAS 890604-48-5](/s/SZGMOQARKQJZSW-UHFFFAOYSA-N.svg)
4-[(1,3-Dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-N,N,3,5-tetramethyl-1H-pyrazole-1-sulfonamide
CAS 890604-48-5C16H18N4O4S
7-Benzyl-8-((2,3-dihydroxypropyl)thio)-3-methyl-1H-purine-2,6(3H,7H)-dione
CAS 378198-70-0C16H18N4O4S
1-(2-Nitrophenyl)sulfonyl-4-(pyridin-4-ylmethyl)piperazine
CAS 429622-58-2C16H18N4O4S
1-(2-Nitrophenyl)sulfonyl-4-(pyridin-2-ylmethyl)piperazine
CAS 428827-97-8C16H18N4O4S
![N-(2-tert-Butyl-5-oxo-4,6-dihydrothieno[3,4-c]pyrazol-3-yl)-2-nitrobenzamide chemical structure, C16H18N4O4S, CAS 958703-02-1](/s/YYEFHZGUHGEGIC-UHFFFAOYSA-N.svg)
N-(2-tert-Butyl-5-oxo-4,6-dihydrothieno[3,4-c]pyrazol-3-yl)-2-nitrobenzamide
CAS 958703-02-1C16H18N4O4S
N-(5-Cyclopropyl-1,3,4-oxadiazol-2-yl)-4-(pyrrolidin-1-ylsulfonyl)benzamide
CAS 685837-34-7C16H18N4O4S
1-(4-Methylbenzenesulfonyl)-4-(3-nitropyridin-2-yl)piperazine
CAS 940247-09-6C16H18N4O4S
![(2R,3R,4R,5R)-2-[4-Amino-5-(2-thienyl)pyrrolo[2,3-d]pyrimidin-7-yl]-5-(hydroxymethyl)-3-methyl-tetrahydrofuran-3,4-diol chemical structure, C16H18N4O4S, CAS 1214752-32-5](/s/YJAZFMYSZBPQEB-KHTZZEJVSA-N.svg)
(2R,3R,4R,5R)-2-[4-Amino-5-(2-thienyl)pyrrolo[2,3-d]pyrimidin-7-yl]-5-(hydroxymethyl)-3-methyl-tetrahydrofuran-3,4-diol
CAS 1214752-32-5C16H18N4O4S
![(2R,3R,4R,5R)-2-[4-Amino-5-(3-thienyl)pyrrolo[2,3-d]pyrimidin-7-yl]-5-(hydroxymethyl)-3-methyl-tetrahydrofuran-3,4-diol chemical structure, C16H18N4O4S, CAS 1252858-70-0](/s/XBPVCSYOZKWBCN-QTDMDRALSA-N.svg)
(2R,3R,4R,5R)-2-[4-Amino-5-(3-thienyl)pyrrolo[2,3-d]pyrimidin-7-yl]-5-(hydroxymethyl)-3-methyl-tetrahydrofuran-3,4-diol
CAS 1252858-70-0C16H18N4O4S
![2-[4-(2,3-Dihydro-1,4-benzodioxin-6-ylsulfonyl)piperazin-1-yl]pyrazine chemical structure, C16H18N4O4S, CAS 794541-48-3](/s/XBBLINZOVBXLHK-UHFFFAOYSA-N.svg)
2-[4-(2,3-Dihydro-1,4-benzodioxin-6-ylsulfonyl)piperazin-1-yl]pyrazine
CAS 794541-48-3C16H18N4O4S
6-Oxo-N-(4-(2-oxo-2-(((tetrahydrofuran-2-yl)methyl)amino)ethyl)thiazol-2-yl)-1,6-dihydropyridine-3-carboxamide
CAS 946336-70-5C16H18N4O4S
2-((6-Acetamidopyridazin-3-yl)thio)-N-(2,4-dimethoxyphenyl)acetamide
CAS 1021056-89-2C16H18N4O4S
2-((6-Acetamidopyridazin-3-yl)thio)-N-(3,5-dimethoxyphenyl)acetamide
CAS 1021060-58-1C16H18N4O4S
N-(6-((2-Oxo-2-(((tetrahydrofuran-2-yl)methyl)amino)ethyl)thio)pyridazin-3-yl)furan-2-carboxamide
CAS 1021061-65-3C16H18N4O4S
N-Cyclopropyl-2-(2-((2-((furan-2-ylmethyl)amino)-2-oxoethyl)thio)-6-oxo-1,6-dihydropyrimidin-4-yl)acetamide
CAS 1105217-43-3C16H18N4O4S
![N-[2-(1H-Indol-3-yl)ethyl]-1,3-dimethyl-2,4-dioxopyrimidine-5-sulfonamide chemical structure, C16H18N4O4S, CAS 874806-87-8](/s/MHFWCZVFXOBVJB-UHFFFAOYSA-N.svg)
N-[2-(1H-Indol-3-yl)ethyl]-1,3-dimethyl-2,4-dioxopyrimidine-5-sulfonamide
CAS 874806-87-8C16H18N4O4S
![Methyl 6-acetyl-2-(1-methyl-1H-pyrazole-5-carboxamido)-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate chemical structure, C16H18N4O4S, CAS 1172954-82-3](/s/FPRHZJOQOMWCCI-UHFFFAOYSA-N.svg)
Methyl 6-acetyl-2-(1-methyl-1H-pyrazole-5-carboxamido)-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate
CAS 1172954-82-3C16H18N4O4S
2-((6-Acetamidopyridazin-3-yl)thio)-N-(3,4-dimethoxyphenyl)acetamide
CAS 1021120-74-0C16H18N4O4S
2-Oxo-N-(4-(2-oxo-2-(((tetrahydrofuran-2-yl)methyl)amino)ethyl)thiazol-2-yl)-1,2-dihydropyridine-3-carboxamide
CAS 952991-40-1C16H18N4O4S
Dabsyl-glycine
CAS 89131-05-5C16H18N4O4S
![N-(4-Acetyl-1'-ethyl-5'-methoxy-2'-oxospiro[1,3,4-thiadiazole-5,3'-indole]-2-yl)acetamide chemical structure, C16H18N4O4S, CAS 577998-82-4](/s/DVWYZOOQEFCIFI-UHFFFAOYSA-N.svg)
N-(4-Acetyl-1'-ethyl-5'-methoxy-2'-oxospiro[1,3,4-thiadiazole-5,3'-indole]-2-yl)acetamide
CAS 577998-82-4C16H18N4O4S
- N-[5-(Methoxymethyl)-1,3,4-thiadiazol-2-yl]-1-(3-methoxyphenyl)-5-oxopyrrolidine-3-carboxamide924965-64-0C16H18N4O4S
- 4-(4-Cyano-5-morpholinooxazol-2-yl)-N,N-dimethylbenzenesulfonamide941264-96-6C16H18N4O4S
- Ethyl 5-[(3-carbamoyl-5,6-dihydro-4H-cyclopenta[b]thiophen-2-yl)carbamoyl]-1-methylpyrazole-3-carboxylate512808-68-3C16H18N4O4S
- N-[5-(Methoxymethyl)-1,3,4-thiadiazol-2-yl]-1-(4-methoxyphenyl)-5-oxopyrrolidine-3-carboxamide878426-62-1C16H18N4O4S
- 1-(2,4-Dimethoxyphenyl)-N-(5-methyl-1,3,4-thiadiazol-2-yl)-5-oxopyrrolidine-3-carboxamide931371-45-8C16H18N4O4S
- 5-(Dimethylamino)-2-[4-(morpholin-4-ylsulfonyl)phenyl]-1,3-oxazole-4-carbonitrile941244-76-4C16H18N4O4S
- 2-((Z)-2-((E)-(4-Morpholinobenzylidene)hydrazono)-4-oxothiazolidin-5-yl)acetic acid326173-57-3C16H18N4O4S
- N-[4-[Acetyl-(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenyl]acetamide (Diacetylsulfadimidine59224-69-0C16H18N4O4S
- 1-(2,5-Dimethoxyphenyl)-N-(5-methyl-1,3,4-thiadiazol-2-yl)-5-oxopyrrolidine-3-carboxamide931374-13-9C16H18N4O4S
- 3-[3-({2-[(3,4-Dimethylphenyl)amino]-2-oxoethyl}sulfanyl)-5-hydroxy-1,2,4-triazin-6-yl]propanoic acid881433-41-6C16H18N4O4S
- 3-[3-({2-[(4-Ethylphenyl)amino]-2-oxoethyl}sulfanyl)-5-hydroxy-1,2,4-triazin-6-yl]propanoic acid881433-46-1C16H18N4O4S
- 7-(2-Hydroxy-3-(o-tolyloxy)propyl)-8-mercapto-3-methyl-1H-purine-2,6(3H,7H)-dione392249-22-8C16H18N4O4S
- N-(4-Methoxyphenyl)-4,4-dimethyl-3,8-dioxo-1-sulfanylidene-6,7-dihydropyrazolo[1,2-a][1,2,4]triazine-6-carboxamide956186-90-6C16H18N4O4S
- 4-Methyl-3-(morpholin-4-ylsulfonyl)-N-(pyrazin-2-yl)benzamide890594-84-0C16H18N4O4S
- 5-(Ethylamino)-2-[4-(morpholin-4-ylsulfonyl)phenyl]-1,3-oxazole-4-carbonitrile941267-39-6C16H18N4O4S
- N-(2-(tert-Butyl)-5-oxido-4,6-dihydro-2H-thieno[3,4-c]pyrazol-3-yl)-3-nitrobenzamide1007194-30-0C16H18N4O4S
- 1-Butan-2-yl-4-(3-nitrophenyl)-4,8-dihydro-2H-pyrazolo[3,4-e][1,4]thiazepine-3,7-dione692269-17-3C16H18N4O4S
- 3-Hydroxy-N-(3-methoxyphenyl)-4,4-dimethyl-8-oxo-1-thioxo-1,4,7,8-tetrahydro-6H-pyrazolo[1,2-a][1,2,4]triazine-6-carboxamide956614-92-9C16H18N4O4S
- 2-{[5-(1,3-Benzodioxol-5-yl)-4-(tetrahydrofuran-2-ylmethyl)-4H-1,2,4-triazol-3-yl]sulfanyl}acetamide886636-96-0C16H18N4O4S
- 2-{4-[5-Hydroxy-2-(methylamino)-6,7-dihydro[1,3]thiazolo[4,5-b]pyridin-7-yl]-2-methoxyphenoxy}acetamide1276345-73-3C16H18N4O4S
- Tenatoprazole sulfone223713-77-7C16H18N4O4S
- 3-(5-(1-(Cyclopropylsulfonyl)azetidin-3-yl)-1,2,4-oxadiazol-3-yl)-N-methylbenzamide1396795-16-6C16H18N4O4S
- Ethyl 2-(6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-2-carboxamido)-5,6-dihydro-4H-cyclopenta[d]thiazole-4-carboxylate1448134-42-6C16H18N4O4S
- N-(2-(3-(Furan-2-yl)-6-oxopyridazin-1(6H)-yl)ethyl)-5-oxo-1,4-thiazepane-3-carboxamide1396629-73-4C16H18N4O4S
- Methyl 5-methyl-2-{[(3-oxo-5,6,7,8-tetrahydrocinnolin-2(3H)-yl)acetyl]amino}-1,3-thiazole-4-carboxylate1574336-85-8C16H18N4O4S
- 3-[3-({2-[(2,3-Dimethylphenyl)amino]-2-oxoethyl}sulfanyl)-5-hydroxy-1,2,4-triazin-6-yl]propanoic acid881433-44-9C16H18N4O4S
- 1-(4-Nitrophenyl)sulfonyl-4-(pyridin-3-ylmethyl)piperazine499209-75-5C16H18N4O4S
- 1-(4-Nitrophenyl)sulfonyl-4-(pyridin-2-ylmethyl)piperazine488744-19-0C16H18N4O4S
- 1-(4-Nitrophenyl)sulfonyl-4-(pyridin-4-ylmethyl)piperazine488732-27-0C16H18N4O4S
- N-(5-Cyclohexyl-1,3,4-thiadiazol-2-yl)-4-methoxy-3-nitrobenzamide524676-99-1C16H18N4O4S
- 1-Butan-2-yl-4-(4-nitrophenyl)-4,8-dihydro-2H-pyrazolo[3,4-e][1,4]thiazepine-3,7-dione692280-51-6C16H18N4O4S
- N-[(2E)-5-(Methoxymethyl)-1,3,4-thiadiazol-2(3H)-ylidene]-1-(2-methoxyphenyl)-5-oxopyrrolidine-3-carboxamide1144448-97-4C16H18N4O4S
- 7,8-Dimethoxy-2-[(tetrahydro-2-furanylmethyl)amino]-5H-[1,3,4]thiadiazolo[2,3-b]quinazolin-5-one1021223-46-0C16H18N4O4S
- N-[(2Z)-6-Methoxy-1,3-benzothiazol-2(3H)-ylidene]-4-oxo-4-(3-oxopiperazin-1-yl)butanamide1219579-46-0C16H18N4O4S
- 4-Amino-N5-[(2H-1,3-benzodioxol-5-yl)methyl]-N3-(propan-2-yl)-1,2-thiazole-3,5-dicarboxamide1286712-96-6C16H18N4O4S
- N-(1,1-Dioxidotetrahydrothiophen-3-yl)-1-(2H-indazol-3-yl)-5-oxopyrrolidine-3-carboxamide1436005-42-3C16H18N4O4S
- N-((1-Methyl-4,5,6,7-tetrahydro-1H-indazol-3-yl)methyl)-2-oxo-2,3-dihydrobenzo[d]oxazole-5-sulfonamide1448126-19-9C16H18N4O4S
- 5'-OH Tenatoprazole223713-85-7C16H18N4O4S
- 3-[3-({2-[(2,6-Dimethylphenyl)amino]-2-oxoethyl}sulfanyl)-5-hydroxy-1,2,4-triazin-6-yl]propanoic acid898607-46-0C16H18N4O4S
- 3-(3-((2-((2,4-Dimethylphenyl)amino)-2-oxoethyl)thio)-5-oxo-4,5-dihydro-1,2,4-triazin-6-yl)propanoic acid881433-38-1C16H18N4O4S
- 1-(2-Nitrophenyl)sulfonyl-4-(pyridin-3-ylmethyl)piperazine428823-89-6C16H18N4O4S
- N-(2-Hydroxyethyl)-N'-[2-(4-methoxyphenyl)-4,6-dihydrothieno[3,4-c]pyrazol-3-yl]oxamide900009-98-5C16H18N4O4S
- N'-(5,5-Dioxo-2-phenyl-4,6-dihydrothieno[3,4-c]pyrazol-3-yl)-N-propyloxamide899988-95-5C16H18N4O4S
- Ethyl (4-(2-((4-acetamidophenyl)amino)-2-oxoethyl)thiazol-2-yl)carbamate946314-65-4C16H18N4O4S
- 4-({4-[(5-Methyl-2-furyl)methyl]piperazinyl}sulfonyl)benzo[c]1,2,5-oxadiazole886630-35-9C16H18N4O4S
- N1-(2-(dimethylamino)-2-(thiophen-2-yl)ethyl)-N2-(4-nitrophenyl)oxalamide942011-91-8C16H18N4O4S
- N1-(2-(dimethylamino)-2-(thiophen-2-yl)ethyl)-N2-(3-nitrophenyl)oxalamide941932-46-3C16H18N4O4S
- 2-((6-Acetamidopyridazin-3-yl)thio)-N-(2,5-dimethoxyphenyl)acetamide1021091-39-3C16H18N4O4S
- 1-Acetyl-N-(2-(6-oxopyridazin-1(6H)-yl)ethyl)indoline-5-sulfonamide1040657-33-7C16H18N4O4S
- N-(4-{[3-(3-Cyclopropyl-1,2,4-oxadiazol-5-yl)azetidin-1-yl]sulfonyl}phenyl)acetamide1351597-46-0C16H18N4O4S
- 4,7-Dimethoxy-N-(5-(methoxymethyl)-1,3,4-thiadiazol-2-yl)-1-methyl-1H-indole-2-carboxamide1351696-37-1C16H18N4O4S
- Ethyl (5-(5-cyclopropylisoxazole-3-carbonyl)-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)carbamate1351615-73-0C16H18N4O4S
- Ethyl 2-(6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-3-carboxamido)-5,6-dihydro-4H-cyclopenta[d]thiazole-4-carboxylate1428374-68-8C16H18N4O4S
- N-(2-(Allylthio)-4-amino-6-oxo-1,6-dihydropyrimidin-5-yl)-3,4-dimethoxybenzamide868226-82-8C16H18N4O4S
- Methyl 2-((4-amino-5-benzamido-6-oxo-1,6-dihydropyrimidin-2-yl)thio)butanoate888415-05-2C16H18N4O4S
- Ethyl 4-[3-(6-amino-4-oxo-3-hydropyrimidin-2-ylthio)propanoylamino]benzoate1246644-49-4C16H18N4O4S
- 4-(N,N-Diallylsulfamoyl)-N-(5-methyl-1,3,4-oxadiazol-2-yl)benzamide850936-52-6C16H18N4O4S
- N-Des(cyclohexylaminocarbonyl)-N-acetyl Glipizide104838-12-2C16H18N4O4S
- tert-Butyl 4-(2-amino-3-nitropyridin-4-ylthio)phenylcarbamate1147504-01-5C16H18N4O4S
- N-(4-{[(1-Cyano-2-methoxy-1-methylethyl)carbamoyl]methyl}-1,3-thiazol-2-yl)-2-methylfuran-3-carboxamide1427687-97-5C16H18N4O4S
- N-(4-(Methylsulfonyl)phenyl)-6-morpholinopyrimidine-4-carboxamide1903297-78-8C16H18N4O4S
- N-(4-(2-(Methylamino)-2-oxoethyl)thiazol-2-yl)-2-((tetrahydrofuran-3-yl)oxy)nicotinamide2034272-19-8C16H18N4O4S
- N-(4-((3-(Pyrimidin-4-yloxy)pyrrolidin-1-yl)sulfonyl)phenyl)acetamide2034247-12-4C16H18N4O4S
- Ethyl 2-(2-(3-cyclopropyl-6-oxopyridazin-1(6H)-yl)acetamido)-4-methylthiazole-5-carboxylate2034268-00-1C16H18N4O4S
- 2-(3-Oxo-3,5,6,7-tetrahydro-2H-cyclopenta[c]pyridazin-2-yl)-N-(4-sulfamoylphenyl)propanamide2034307-69-0C16H18N4O4S
- Ethyl 2-(2-(3-oxo-3,5,6,7-tetrahydro-2H-cyclopenta[c]pyridazin-2-yl)propanamido)thiazole-5-carboxylate2097932-25-5C16H18N4O4S
- 3-(3-((2-((2,5-Dimethylphenyl)amino)-2-oxoethyl)thio)-5-oxo-4,5-dihydro-1,2,4-triazin-6-yl)propanoic acid898635-31-9C16H18N4O4S
- 3-(3-((2-((2-Ethylphenyl)amino)-2-oxoethyl)thio)-5-oxo-4,5-dihydro-1,2,4-triazin-6-yl)propanoic acid898607-71-1C16H18N4O4S
- 3-(3-((2-((3,5-Dimethylphenyl)amino)-2-oxoethyl)thio)-5-oxo-4,5-dihydro-1,2,4-triazin-6-yl)propanoic acid898607-55-1C16H18N4O4S
- 3-(3-((2-((3-Ethylphenyl)amino)-2-oxoethyl)thio)-5-oxo-4,5-dihydro-1,2,4-triazin-6-yl)propanoic acid898607-49-3C16H18N4O4S
- 6-((3,5-Dimethoxybenzyl)thio)-1-(2-hydroxyethyl)-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one946255-30-7C16H18N4O4S
- Ethyl 7-(3,4-dihydroxyphenyl)-5-methyl-2-(methylthio)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate941897-14-9C16H18N4O4S
- N-((4-Diethylaminophenyl)thiocarbamoyl)-5-nitrofuran-3-carboxamide117457-82-6C16H18N4O4S
- 1H-Pyridazino(4,5-b)(1,4)benzothiazin-1-one, 2,10-dihydro-2-(2-(4-morpholinyl)ethyl)-, 5,5-dioxide126598-44-5C16H18N4O4S
- N-(4-Acetylphenyl)-2-((1-(2-amino-2-oxoethyl)-5-(hydroxymethyl)-1H-imidazol-2-yl)thio)acetamide921846-13-1C16H18N4O4S
- Methyl 3-amino-6-[4-(pyrrolidin-1-ylsulfonyl)phenyl]pyrazine-2-carboxylate486423-09-0C16H18N4O4S
Frequently asked questions
What is the molar mass of C16H18N4O4S?
The molar mass of C16H18N4O4S is 362.40 g/mol, calculated from standard atomic weights for 16 carbon atoms, 18 hydrogen atoms, 4 nitrogen atoms, 4 oxygen atoms and 1 sulfur atom. The monoisotopic mass is 362.1049 Da.
How many compounds have the formula C16H18N4O4S?
CompoundList lists 111 compounds with the molecular formula C16H18N4O4S, including 5-(Furan-2-yl(1,4-dioxa-8-azaspiro[4.5]decan-8-yl)methyl)thiazolo[3,2-b][1,2,4]triazol-6-ol, N-((5-((2-Morpholino-2-oxoethyl)thio)-1,3,4-oxadiazol-2-yl)methyl)benzamide, 1-[(4-Methylphenyl)sulfonyl]-4-(5-nitro-2-pyridinyl)piperazine. 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 C16H18N4O4S?
C16H18N4O4S has a degree of unsaturation of 10. 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.