Substituted imidazo[1,2-a]pyrazines as luciferase substrates
Described are substituted imidazo[1,2-a]pyrazine compounds, which are coelenterazine analogs, kits comprising the compounds, and methods of using the compounds for the detection of luminescence in luciferase-based assays. Also described are methods for making the compounds, such as a method using aminopyrazine acetophosphonates as synthesis intermediates.
1. A compound of formula (I):
or a tautomer or pharmaceutically acceptable salt thereof,
wherein:
R 1 is phenyl; and
q is 1;
wherein said phenyl is substituted with 1, 2, 3, 4, or 5 functional groups independently selected from the group consisting of cyano, carbamate, nitro, alkyl, alkenyl, alkynyl, haloalkyl, haloalkoxy, heteroalkyl, cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocyclyl, heterocycloalkyl, cycloalkylalkyl, heteroarylalkyl, arylalkyl, hydroxy, hydroxyalkyl, alkoxy, allyloxy, aryloxy, benzyloxy, amino, aminoalkyl, sulfonylamino, sulfinylamino, sulfonyl, sulfinyl, —COOH, amide, carbamate, silyl, silyloxy, sulfanyl, and acyl;
provided that R 1 is not
wherein R c is OH, OC(O)C 1 -C 7 -alkyl, or OCH 2 OC(O)C 1 -C 7 -alkyl.
2. The compound of claim 1 , or a tautomer or pharmaceutically acceptable salt thereof, wherein said phenyl is substituted with 1 or 2 functional groups independently selected from the group consisting of cyano, carbamate, alkyl, haloalkyl, heteroalkyl, aryl, hydroxy, alkoxy, allyloxy, amino, aminoalkyl, sulfonylamino, —COOH, and alkylsulfanyl.
3. The compound of claim 1 , wherein the compound is selected from the group consisting of:
8-benzyl-2-(3-methoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-hydroxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-methoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
tert-butyl (3-((8-benzyl-3-oxo-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-2-yl)methyl)phenyl) carbamate;
2-(3-aminobenzyl)-8-benzyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-(tert-butyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
2-([1,1′-biphenyl]-4-ylmethyl)-8-benzyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
tert-butyl (4-((8-benzyl-3-oxo-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-2-yl)methyl)phenyl)carbamate;
2-(4-aminobenzyl)-8-benzyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
2-(4-(allyloxy)-3-methoxybenzyl)-8-benzyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-hydroxy-3-methoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
4-((8-benzyl-3-oxo-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-2-yl)methyl)benzoic acid;
8-benzyl-2-(3,5-bis (trifluoromethyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
3-((8-benzyl-3-oxo-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-2-yl)methyl)benzoic acid;
2-(3-(aminomethyl)benzyl)-8-benzyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
N-(3-((8-benzyl-3-oxo-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-2-yl)methyl)phenyl) methanesulfonamide;
8-benzyl-2-(4-methoxy-3-(methoxymethyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-(dimethylamino)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-(methoxymethyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-(hydroxymethyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3,4-dimethoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-(methylthio)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-((dimethylamino)methyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-ethoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-(2-methoxyethoxy)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one; and
3-((8-benzyl-3-oxo-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-2-yl)methyl)benzonitrile;
or a tautomer or pharmaceutically acceptable salt thereof.
4. A kit comprising a compound of claim 1 , or a tautomer or pharmaceutically acceptable salt thereof.
5. The kit of claim 4 , wherein the kit further comprises a luciferase.
6. The kit of claim 4 , wherein the kit further comprises a buffer reagent.
7. A method for detecting luminescence in a sample, the method comprising:
contacting a sample with a compound of claim 1 , or a tautomer or pharmaceutically acceptable salt thereof;
contacting the sample with a coelenterazine-utilizing luciferase, if it is not present in the sample; and
detecting luminescence.
8. The method of claim 7 , wherein the sample contains live cells.
9. The method of claim 7 , wherein the sample contains a coelenterazine-utilizing luciferase.
10. A method for detecting luminescence in a transgenic animal comprising:
administering a compound of claim 1 , or a tautomer or pharmaceutically acceptable salt thereof to a transgenic animal; and
detecting luminescence;
wherein the transgenic animal expresses a coelenterazine-utilizing luciferase.
11. A compound of formula (I):
or a tautomer or pharmaceutically acceptable salt thereof,
wherein:
R 1 is phenyl; and
q is 1;
wherein said phenyl is substituted with 2, 3, 4, or 5 functional groups independently selected from the group consisting of halogen, cyano, carbamate, nitro, alkyl, alkenyl, alkynyl, haloalkyl, haloalkoxy, heteroalkyl, cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocyclyl, heterocycloalkyl, cycloalkylalkyl, heteroarylalkyl, arylalkyl, hydroxy, hydroxyalkyl, alkoxy, allyloxy, aryloxy, benzyloxy, amino, aminoalkyl, sulfonylamino, sulfinylamino, sulfonyl, sulfinyl, —COOH, amide, carbamate, silyl, silyloxy, sulfanyl, and acyl.
12. The compound of claim 11 , or a tautomer or pharmaceutically acceptable salt thereof, wherein said phenyl is substituted with 2, 3, 4, or 5 functional groups independently selected from the group consisting of halogen, haloalkyl, heteroalkyl, hydroxy, alkoxy, and allyloxy.
13. The compound of claim 11 , wherein the compound is selected from the group consisting of:
8-benzyl-2-(2,4-difluorobenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-fluoro-3-methoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-fluoro-3-hydroxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3-fluoro-4-methoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-fluoro-2-methoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
2-(4-(allyloxy)-3-methoxybenzyl)-8-benzyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-hydroxy-3-methoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-((perfluorophenyl)methyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3,5-bis (trifluoromethyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(4-methoxy-3-(methoxymethyl)benzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one;
8-benzyl-2-(3,4-dimethoxybenzyl)-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one; and
8-benzyl-6-phenyl-2-(2,4,6-trifluorobenzyl)imidazo[1,2-a]pyrazin-3(7H)-one,
or a tautomer or pharmaceutically acceptable salt thereof.
14. A kit comprising a compound of claim 11 , or a tautomer or pharmaceutically acceptable salt thereof.
15. The kit of claim 14 , wherein the kit further comprises a luciferase.
16. The kit of claim 14 , wherein the kit further comprises a buffer reagent.