(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine

C141H170F19N17O4 — CID 158912293

About (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine

(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine (PubChem CID 158912293) has the molecular formula C141H170F19N17O4 and a molecular weight of 2527.99 g/mol. Its IUPAC name is (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine.

Molecular Properties

• Compound Name: (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine
• PubChem CID: 158912293
• Molecular Formula: C141H170F19N17O4
• Molecular Weight: 2527.99 g/mol
• Exact Mass: 2526.33
• IUPAC Name: (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine
• SMILES: CCCCN1CC(Nc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(C)(C)F)c(F)c2)C1.CCCCN1CC(Nc2cc(F)c([C@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(F)(F)F)c(F)c2)C1.CCCCN1CC(Oc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(C)(C)F)c(F)c2)C1.CCCCN1CC(Oc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(C)(F)CO)c(F)c2)C1.CCCCN1CC(Oc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(F)(F)F)c(F)c2)C1
• InChI: InChI=1S/C29H37F3N4.C29H36F3N3O2.C29H36F3N3O.C27H31F5N4.C27H30F5N3O/c1-5-6-11-34-16-22(17-34)33-21-13-23(30)27(24(31)14-21)28-26-12-20-9-7-8-10-25(20)35(26)15-19(2)36(28)18-29(3,4)32;1-4-5-10-33-15-22(16-33)37-21-12-23(30)27(24(31)13-21)28-26-11-20-8-6-7-9-25(20)34(26)14-19(2)35(28)17-29(3,32)18-36;1-5-6-11-33-16-22(17-33)36-21-13-23(30)27(24(31)14-21)28-26-12-20-9-7-8-10-25(20)34(26)15-19(2)35(28)18-29(3,4)32;1-3-4-9-34-14-20(15-34)33-19-11-21(28)25(22(29)12-19)26-24-10-18-7-5-6-8-23(18)35(24)13-17(2)36(26)16-27(30,31)32;1-3-4-9-33-14-20(15-33)36-19-11-21(28)25(22(29)12-19)26-24-10-18-7-5-6-8-23(18)34(24)13-17(2)35(26)16-27(30,31)32/h7-10,12-14,19,22,28,33H,5-6,11,15-18H2,1-4H3;6-9,11-13,19,22,28,36H,4-5,10,14-18H2,1-3H3;7-10,12-14,19,22,28H,5-6,11,15-18H2,1-4H3;5-8,10-12,17,20,26,33H,3-4,9,13-16H2,1-2H3;5-8,10-12,17,20,26H,3-4,9,13-16H2,1-2H3/t19-,28+;19-,28+,29?;19-,28+;17-,26-;17-,26+/m11111/s1
• InChIKey: JGUMERUZWVQKCF-YNRYGFSCSA-N
• XLogP: 30.29
• TPSA: 129.03 Ų
• H-Bond Donors: 3
• H-Bond Acceptors: 21
• Rotatable Bonds: 39
• Heavy Atoms: 181
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	2527.99
LogP ≤ 5	30.29
H-Bond Donors ≤ 5	3
H-Bond Acceptors ≤ 10	21

Frequently Asked Questions

What is the IUPAC name of (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine?

The IUPAC name of (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine (CID 158912293) is (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine.

What is the SMILES notation for (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine?

The canonical SMILES for (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine is CCCCN1CC(Nc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(C)(C)F)c(F)c2)C1.CCCCN1CC(Nc2cc(F)c([C@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(F)(F)F)c(F)c2)C1.CCCCN1CC(Oc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(C)(C)F)c(F)c2)C1.CCCCN1CC(Oc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(C)(F)CO)c(F)c2)C1.CCCCN1CC(Oc2cc(F)c([C@@H]3c4cc5ccccc5n4C[C@@H](C)N3CC(F)(F)F)c(F)c2)C1.

What is the InChIKey of (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine?

The InChIKey is JGUMERUZWVQKCF-YNRYGFSCSA-N. The full InChI is InChI=1S/C29H37F3N4.C29H36F3N3O2.C29H36F3N3O.C27H31F5N4.C27H30F5N3O/c1-5-6-11-34-16-22(17-34)33-21-13-23(30)27(24(31)14-21)28-26-12-20-9-7-8-10-25(20)35(26)15-19(2)36(28)18-29(3,4)32;1-4-5-10-33-15-22(16-33)37-21-12-23(30)27(24(31)13-21)28-26-11-20-8-6-7-9-25(20)34(26)14-19(2)35(28)17-29(3,32)18-36;1-5-6-11-33-16-22(17-33)36-21-13-23(30)27(24(31)14-21)28-26-12-20-9-7-8-10-25(20)34(26)15-19(2)35(28)18-29(3,4)32;1-3-4-9-34-14-20(15-34)33-19-11-21(28)25(22(29)12-19)26-24-10-18-7-5-6-8-23(18)35(24)13-17(2)36(26)16-27(30,31)32;1-3-4-9-33-14-20(15-33)36-19-11-21(28)25(22(29)12-19)26-24-10-18-7-5-6-8-23(18)34(24)13-17(2)35(26)16-27(30,31)32/h7-10,12-14,19,22,28,33H,5-6,11,15-18H2,1-4H3;6-9,11-13,19,22,28,36H,4-5,10,14-18H2,1-3H3;7-10,12-14,19,22,28H,5-6,11,15-18H2,1-4H3;5-8,10-12,17,20,26,33H,3-4,9,13-16H2,1-2H3;5-8,10-12,17,20,26H,3-4,9,13-16H2,1-2H3/t19-,28+;19-,28+,29?;19-,28+;17-,26-;17-,26+/m11111/s1.

What are the key properties of (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine?

(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine has a molecular weight of 2527.99 g/mol, XLogP of 30.29, 39 rotatable bonds, 3 hydrogen bond donors, and 21 hydrogen bond acceptors.

Where does this data come from?

All data for (1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indole;3-[(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-2-yl]-2-fluoro-2-methylpropan-1-ol;(1R,3R)-1-[4-(1-butylazetidin-3-yl)oxy-2,6-difluorophenyl]-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indole;1-butyl-N-[3,5-difluoro-4-[(1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine;1-butyl-N-[3,5-difluoro-4-[(1S,3R)-3-methyl-2-(2,2,2-trifluoroethyl)-3,4-dihydro-1H-pyrazino[1,2-a]indol-1-yl]phenyl]azetidin-3-amine is sourced from PubChem (CID 158912293), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).