Table 4. Non-teratogenic analogues of thalidomide; replacement of the phthalimide ring by alternative ring structures with intact glutarimide function.

Name	Systematic name	Structure	Test species and references
3-(1,3-Dihydro-1-oxo-2H-isoindol-2-yl)-2,6-dioxopiperidine [25]	3-(1,1-Dioxido-1,2-benzothiazol-2(3H)-yl)piperidine-2,6-dione		Rabbit46
2-(3-Oxo-1,2-benzisothiazolin-2-yl)glutarimide-S,S-dioxide [26]	3-(1,1-Dioxido-3-oxo-1,2-benzothiazol-2(3H)-yl)piperidine-2,6-dione		Rabbit47
EM8 3-(2,3-Dihydro-1,1-dioxido-3-oxo-1,2-benzoisothiazol-2-yl)-2,6-dioxopiperidine [27]	3-(1,1-Dioxido-3-oxo-1,2-benzothiazol-2(3H)-yl)piperidine-2,6-dione		Rabbit37,46
2-(4-Oxo-3,4-dihydroquinazolin-3-yl)-glutarimide [28]	3-(4-Oxoquinazolin-3(4H)-yl)piperidine-2,6-dione		Rabbit47
2-(Hexahydrophthalimido)-glutarimide [29]	2-(2,6-Dioxopiperidin-3-yl)hexahydro-1H-isoindole-1,3(2H)-dione		Rabbit33,36
3-(1,4-Endoxocyclohexan-2-exo-3-exo-dicarboximido)-piperidin-2,6-dione [30]	4-(2,6-Dioxopiperidin-3-yl)-10-oxa-4-azatricyclo[5.2.1.02,6]decane-3,5-dione		Rabbit48,49
3-(1,4-Endomethylene-cyclohexane-2,3-endo-cis-dicarboximido)-piperidin-2,6-dione [31]	4-(2,6-Dioxopiperidin-3-yl)-4-azatricyclo[5.2.1.02,6]decane-3,5-dione		Rabbit48,49
α-Succinimidoglutarimide [32]	3-(2,5-Dioxopyrrolidin-1-yl)piperidine-2,6-dione		Rabbit34