| Hydralazine/derivative | Structure | Notation | Molecular Weight (g・mol−1) |
| Hydralazine hydrochloride |
| 1 | 196.637 |
| 1-(phthalazin-1(2H)-one) [(pyridin-2-yl)ethylidene] hydrazone |
| 2 | 263.30 |
| (2-acetylthiophene hydrazono) phthalazine |
| 3 | 268.23 |
| 1-(2-[(5-methylfuran-2-yl) methylene)]hydrazono) phthalazine |
| 4 | 252.28 |