2820-37-3

Basic information

• Product Name: 3,4-DIMETHYL PYRAZOLE
• Synonyms: 3,4-DIMETHYL PYRAZOLE;3,4-Dimethyl-1H-pyrazol;4,5-dimethyl-1H-pyrazole;3,4-Dimethyl-1
• CAS NO: 2820-37-3
• Molecular Formula: C₅H₈N₂
• Molecular Weight: 96.13042
• EINECS: 429-130-1
• Product Categories: Heterocyclic Compounds;Bases & Related Reagents;Heterocycles;Nucleotides
• Mol File: 2820-37-3.mol
• Article Data: 9

Chemical Properties

• Melting Point: 44-46°C
• Boiling Point: 189.67°C (rough estimate)
• Flash Point: 98.7 °C
• Appearance: Cream/Fused Solid
• Density: 0.9325
• Vapor Pressure: 0.168mmHg at 25°C
• Refractive Index: 1.4739 (estimate)
• Storage Temp.: Sealed in dry,Room Temperature
• Solubility: Acetonitrile (Very Slightly), Chloroform (Slightly)
• PKA: 15.51±0.50(Predicted)
• Water Solubility: Slightly soluble in water.
• BRN: 1621
• CAS DataBase Reference: 3,4-DIMETHYL PYRAZOLE(CAS DataBase Reference)
• NIST Chemistry Reference: 3,4-DIMETHYL PYRAZOLE(2820-37-3)
• EPA Substance Registry System: 3,4-DIMETHYL PYRAZOLE(2820-37-3)

Safety Data

• Hazard Codes: Xn
• Statements: 22-41-52/53
• Safety Statements: 26-39-61
• WGK Germany: 3
• Hazardous Substances Data: 2820-37-3(Hazardous Substances Data)

Usage

Chemical Properties

Light Yellow Solid

Uses

3,4-Dimethyl-1H-pyrazole is used as pharmaceutical intermediate.

InChI:InChI=1/C5H8N2/c1-4-3-6-7-5(4)2/h3H,1-2H3,(H,6,7)

Upstream product

• 89364-26-1 2-ethyl-3-hydroxy-acrylaldehyde 
• 41850-84-4 1-methoxy-2-methyl-1-buten-3-one 
• 1187-89-9 1-dimethylamino-2-methyl-1-buten-3-one 
• 3393-64-4 4-hydroxy-3-methyl-2-butanone 
• 563-80-4 3-methyl-butan-2-one 
• 497-03-0 2-methylbut-2-enal 
• 40572-80-3 2-methyl-3-oxo-butyraldehyde 2,3-enol tautomer 
• 7732-18-5 water 
• 7803-57-8 hydrazine hydrate 
• 15754-93-5 3,4-Dimethyl-1-carboxamido-pyrazol 
• 7664-93-9 sulfuric acid 
• 71805-61-3 7,7-dimethyl-2,3-diaza-bicyclo[2.2.1]hept-2-ene 
• 126134-41-6 6-Chloro-2-(3,5-dimethyl-pyrazol-1-yl)-3-ethyl-3H-quinazolin-4-one 
• 89831-40-3 3,4-dimethyl-2H-pyrazole-5-carboxylic acid 

Downstream Products

• 202842-98-6 3,4-dimethylpyrazole phosphate 
• 116436-00-1 3,4-dimethyl-1-phenyl-1H-pyrazole 
• 86402-31-5 4,5-dimethyl-1,2,3-triazine 
• 99939-01-2 3,4-Dimethyl-1H-pyrazol-1-amin 
• 830321-32-9 4,5-Dimethyl-1H-pyrazol-1-amin 

Relevant articles and documents

Preparation method of 3, 4-dimethylpyrazole and phosphate thereof

The invention discloses a preparation method of 3, 4-dimethylpyrazole and phosphate thereof, which comprises the following steps: S1. making 2-butanone react with formate at -10 to 50 DEG C in a reaction solvent under the condition of keeping alkaline by using an alkaline substance, carrying out extraction separation, adding an alkylation reagent, continuing the reaction to obtain a reaction solution, and carrying out post-treatment to obtain a solution of an alkene ether compound, and S2, making the alkene ether compound prepared in the step S1 react with hydrazine hydrate or hydrazine salt at the temperature of -10 to 60 DEG C after the pH value is adjusted to 2-9, adding the alkaline substance to adjust the pH value to 7-11 after the reaction is finished, and carrying out post-treatmentto obtain the 3, 4-dimethyl pyrazole. The preparation method disclosed by the invention has the remarkable advantages of cheap raw materials, simplicity and convenience in operation, high yield, simplicity in three-waste treatment, high product quality, capability of recycling the solvent and the like, and is suitable for industrial production.

Method for preparing 3, 4-dimethylpyrazole and phosphate thereof

The invention discloses a method for preparing 3, 4-dimethylpyrazole and phosphate thereof. The method for preparing the 3, 4-dimethylpyrazole includes the steps: (1) feeding 2-butanone, aldehyde andalkali solution into a microchannel reactor and performing aldehyde ketone condensation reaction to produce 4-hydroxy-3-methyl-2-butanone salt; (2) mixing reaction liquid obtained in the step (1) andacid liquid in the microchannel reactor to obtain 4-hydroxy-3-methyl-2-butanone water solution; (3) performing reaction on hydrazine hydrate and the 4-hydroxy-3-methyl-2-butanone water solution in themicrochannel reactor, mixing reaction liquid with the alkali solution and hydrogen peroxide, and performing oxidative dehydrogenation reaction to obtain 3, 4-dimethylpyrazole water solution; (4) performing organic extraction and distillation on the 3, 4-dimethylpyrazole water solution to obtain the 3, 4-dimethylpyrazole. According to the method, reaction time is greatly shortened, the yield and the purity of products are ensured, and continuous production can be realized.

Method for producing substituted pyrazoles

Pyrazole derivatives are prepared by reacting carbonyl compounds R1—C(O)—CH(R2)—CH2R3with hydrazine, its hydrate or its salts in 30 to 100% by weight sulfuric acid in the presence of catalytic amounts of iodine or of an iodine compound.