Name | hydralazine |
Synonyms | apresoline NSC 126699 hydralazine 1-Phthalazinylhydrazine Dihydralazine Impurity 2 phthalazin-1-ylhydrazine 1(2h)-phthalazinonehydrazone |
CAS | 86-54-4 |
EINECS | 201-680-3 |
InChI | InChI=1/C8H8N4/c9-11-8-7-4-2-1-3-6(7)5-10-12-8/h1-5H,9H2,(H,11,12) |
Molecular Formula | C8H8N4 |
Molar Mass | 160.18 |
Density | 1.2583 (rough estimate) |
Melting Point | 172°C |
Boling Point | 276.07°C (rough estimate) |
Water Solubility | 4.8mg/L(22.5 ºC) |
pKa | pKa 6.820± 0.005(H2O,t = 25.0,Iundefined) (Uncertain) |
Storage Condition | -20°C |
Refractive Index | 1.5872 (estimate) |
Toxicity | LD50 in mice, rats (mg/kg): 122, 90 orally; 101, 40 i.p. (Dorigotti) |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
(IARC) carcinogen classification | 3 (Vol. 24, Sup 7) 1987 |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
preparation | a process for industrial production of Hydralazine Hydrochloride, using O-cyanobenzaldehyde as raw material, condensation, and then salt with hydrochloric acid, the process steps are: A, hydrogen chloride-ethanol preparation: 1000 liters of industrial hydrochloric acid is added to the distillation kettle with A capacity of 600 liters, and the steam is heated to 100 ° C, the generated hydrogen chloride gas was absorbed by 700 liters of ethanol frozen in ice brine to generate a hydrogen chloride-ethanol solution, and the content of hydrogen chloride-ethanol was finally measured and controlled to 20 to 21%. B. Preparation of hydrazine hydrochloride:(a) 500 liters of hydrazine hydrate and 50% liters of ethanol with a content of 150 are drawn into a high tank with a capacity of 300 liters. (B) the hydrogen chloride-ethanol solution prepared by A is pumped into A reactor with A capacity of 2000 liters, and the brine is passed into the jacket of the reactor to cool down to -10 ~-15 °c, in the case of stirring, slowly drop a preparation, drop time control in 2~3 hours, at this temperature for 4~5 hours, Until the solution was colorless and transparent. C, the preparation of Hydralazine Hydrochloride: In the above capacity of 2000 liters of the reactor, add 100 of O-cyanobenzaldehyde, feeding time of 2 hours (in order to prevent severe reaction, flushing), after completion of feeding, the salt in the reactor jacket shall be pressed away, the heating rate shall be controlled, the temperature shall be increased by 3~5 ℃ per hour, the temperature shall be increased to 45~50 ℃, and the reaction shall be maintained for 24~48 hours, sampling HPLC analysis, after the completion of the reaction, add CP grade hydrochloric acid, adjust the pH value to Ph 2~4, cool, stand, crystallize for 8 hours, centrifuge filter, the filter cake was washed with ethanol 20 L x 3 times and vacuum dried at 100 °c for 8 hours to give a crude product of 120. D, refining: the crude product according to the ratio of 1: 1(M: V) into 200 liters of ethanol aqueous solution, heated to 85 degrees Celsius, Dissolve, add activated carbon 10kg, filter, filtrate frozen crystallization for 8 hours, spin filter, filter cake with ethanol wash 20L x 3 times, at 100 ℃ vacuum drying for 8 hours, the product was 75kg, the yield was 50%, and mp272 ~ 273 ℃. |
Overview | Hydralazine, also known as Hydralazine, is an antihypertensive drug that acts directly on the smooth muscles of arteries and arterioles. It reduces peripheral resistance by relaxing vascular smooth muscle, so as to achieve the purpose of reducing blood pressure. |
Application | hydralazine can be used for patients with moderate and severe hypertension, especially renal hypertension and high diastolic blood pressure, it can also be used for pregnancy toxemia and hypertension caused by acute glomerulonephritis. |
side effects | hydralazine tends to increase heart rate and may result in fluid retention through its effects on the kidneys. These effects are usually offset by the administration of hydralazine, as well as other drugs such as beta-blockers and diuretics, although this is not always possible in pregnant patients. |