4-Methylpyrazole

Fomepizole is a competitive inhibitor of the enzyme alcohol dehydrogenase which plays a key role in the metabolism of ethylene glycol and methanol.

Solid

Fomepizole is a member of the class of pyrazoles that is 1H-pyrazole substituted by a methyl group at position 4. It has a role as an antidote, a protective agent and an EC 1.1.1.1 (alcohol dehydrogenase) inhibitor. It derives from a hydride of a 1H-pyrazole.|Fomepizole is used as an antidote in confirmed or suspected methanol or ethylene glycol poisoning. Fomepizole is a competitive inhibitor of alcohol dehydrogenase, the enzyme that catalyzes the initial steps in the metabolism of ethylene glycol and methanol to their toxic metabolites.|Fomepizole is an Antidote.|Fomepizole is a pyrazole with competitive alcohol dehydrogenase inhibitor activity. Fomepizole prevents the metabolism of ethylene glycol and methanol by alcohol dehydrogenase, thereby inhibiting the formation of their toxic metabolites, glycolate and oxalate (from ethylene glycol), and formic acid (from methanol). Fomepizole is indicated for use as an antidote in ethylene glycol and methanol poisoning. (NCI05)|A pyrazole and competitive inhibitor of ALCOHOL DEHYDROGENASE that is used for the treatment of poisoning by ETHYLENE GLYCOL or METHANOL.

Into a 5 liter flask equipped with a mechanical stirrer were added 1750 ml of sterile USP water to which 266.7 g (2.05 moles) of hydrazine hydrosulfate were added gradually over one hour with stirring. To the above mixture was added dropwise 481 g (2.053 moles) of 3 and the reaction mixture was warmed to 80°C. Heating and stirring were maintained for 3 hours, the flask was cooled to 40°C, and the volatile components were distilled off under a reduced pressure of about 125 mm. The resulting mixture was EPO Into a 5 liter flask equipped with a mechanical stirrer were added 1750 ml of sterile USP water to which 266.7 g (2.05 moles) of hydrazine hydrosulfate were added gradually over one hour with stirring. To the above mixture was added dropwise 481 g (2.053 moles) of 3 and the reaction mixture was warmed to 80 C. Heating and stirring were maintained for 3 hours, the flask was cooled to 40 C., and the volatile components were distilled off under a reduced pressure of about 125 mm. The resulting mixture was cooled to 10 C. first with water and then with glycol; 20 ml of water were added to the flask, and cooling was continued to a temperature of 3 C. Thereafter 50percent sodium hydroxide solution was added with cooling so as to maintain the temperature below 30 C. The pH of the reaction mixture should be between 4 and 6. A solution of sodium bicarbonate containing 4.9 g of sodium bicarbonate to 55 ml of water was added to the flask. Additional sodium bicarbonate solution was added until the pH reached 7.0. The flask temperature was allowed to rise to 27 C. with continued stirring. The contents of the flask were extracted with ethyl acetate and the aqueous layer was separated. The organic layer was dried over magnesium sulfate, filtered, and the extract was distilled under vacuum. The light fraction was removed at a pot temperature of 55-60 C. at 125 mm pressure. The vacuum was improved to 5 mm for the remainder of the distillation; pot temperatures were permitted to rise to 100-110 C. to produce 134.8 g (84percent based on 3) of 4-methylpyrazole, bp 77-80 C. at 5 mm, as a clear, colorless to yellow liquid. Gas chromatographic analysis showed less than 0.1percent pyrazole and less than 10 ppm hydrazine.a, taking 3-amino-2-methyl acrolein 100g, toluene 500ml, Tetrabutylammonium chloride 16.3g was added to the reactor, take formamide 52.9g, Added to 79.4g of water made of 40percent aqueous solution of formamide, added to the reactor, the reaction at room temperature for 1h, Heating to 80 reaction 3h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature, The organic phase was taken, the organic phase was washed three times with 500ml of water, the organic phase was dried over anhydrous magnesium sulfate for 2h, Filtration, the filtrate was evaporated to give crude 4-methylpyrazole 91g;b, 4-methylpyrazole crude distillationThe crude 4-methylpyrazole obtained in step a was added into a vacuum distillation reactor with a rectification column, For the 0.09 ~ 0.097Mpa conditions collected 110 ~ 116 ° C distillate, to give a clear colorless liquid, which is 4 - methyl pyrazole refined products82g

Useful as an antidote in methanol and ethylene glycol poisoning. Antidote in methanol or ethylene glycol poisoning;Alcohol dehydrogenase inhibitor antidote to ethylene glycol or methanol poisoning

Molecular Weight:82.10
XLogP3:1.4
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:1
Exact Mass:82.053098200
Monoisotopic Mass:82.053098200
Topological Polar Surface Area:28.7
Heavy Atom Count:6
Complexity:44.8
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes