Cyclopropyl methyl ketone

Cyclopropyl methyl ketone

Cyclopropyl Methyl Ketone (CAS: 765-43-5) is an organic compound with the molecular formula C₅H₈O. It consists of a cyclopropyl ring attached to a methyl ketone group (–COCH₃), making it a simple yet versatile cyclic ketone.

Key Properties:

Chemical Formula: C₅H₈O

Molecular Weight: 84.12 g/mol

Appearance: Colorless to pale yellow liquid

Odor: Pungent, ketone-like smell

Boiling Point: ~112–114°C

Density: ~0.85 g/cm³

Solubility: Miscible with most organic solvents (ethanol, ether, acetone); slightly soluble in water.

Applications:

Pharmaceutical Intermediates:

Used in the synthesis of drugs containing cyclopropyl groups, such as certain antibiotics, antidepressants, or antiviral agents.

Key precursor for Ciprofloxacin-like quinolone antibiotics.

Agrochemicals:

Building block for pesticides and herbicides that leverage the cyclopropyl ring’s stability.

Flavor & Fragrance:

Contributes to synthetic flavors due to its sharp, ketonic odor (used in trace amounts).

Organic Synthesis:

Participates in Grignard reactions, reductions (to cyclopropylmethanol), and condensations (e.g., aldol reactions).

Used to introduce the cyclopropyl moiety into complex molecules.

Safety & Handling:

Flammability: Highly flammable liquid (flash point ~15°C).

Health Hazards: May cause eye/skin irritation and respiratory discomfort upon inhalation.

Storage: Keep in a tightly sealed container, away from heat/open flames. Store under inert gas (N₂) if long-term stability is needed.

PPE: Wear gloves, goggles, and work in a fume hood.

Synthesis Methods:

From Cyclopropyl Cyanide:

Hydrolysis of cyclopropyl cyanide followed by a Grignard reaction with methyl magnesium bromide.

Oxidation of Cyclopropylmethanol:

Controlled oxidation using PCC (Pyridinium Chlorochromate) or Jones reagent.

Friedel-Crafts Acylation (for Derivatives):

Reaction of cyclopropane with acetyl chloride/AlCl₃ (limited by ring strain).