3721-18-4

Basic information

• Product Name: 5-chlorobicyclo[2.2.1]hept-2-ene
• Synonyms: Bicyclo[2.2.1]hept-2-ene, 5-chloro-, (1R,4R,5R)-rel-
• CAS NO: 3721-18-4
• Molecular Formula: C₇H₉Cl
• Molecular Weight: 128.5994
• Mol File: 3721-18-4.mol
• Article Data: 2

Chemical Properties

• Boiling Point: 174.2°C at 760 mmHg
• Flash Point: 42.9°C
• Density: 1.13g/cm³
• Vapor Pressure: 1.63mmHg at 25°C
• Refractive Index: 1.53
• CAS DataBase Reference: 5-chlorobicyclo[2.2.1]hept-2-ene(CAS DataBase Reference)
• NIST Chemistry Reference: 5-chlorobicyclo[2.2.1]hept-2-ene(3721-18-4)
• EPA Substance Registry System: 5-chlorobicyclo[2.2.1]hept-2-ene(3721-18-4)

Safety Data

• Hazardous Substances Data: 3721-18-4(Hazardous Substances Data)

Upstream product

• 694-97-3 endo-5-norbornen-2-ol 
• 75-01-4 chloroethylene 
• 542-92-7 cyclopenta-1,3-diene 

Relevant articles and documents

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Nortricyclyl-norbornenyl cation system accessed by carbene fragmentation

Fragmentation of nortricyclyloxychlorocarbene 5 in pentane occurs by an SNi-like process which yields nortricyclyl chloride 3g. In more polar solvents, fragmentation leads to nortricyclyl cation chloride anion pairs (9) that give mainly 3g, accompanied by ～10% of exo-2-norbornenyl chloride 4g. From exo-2-norbornenyloxychlorocarbene 6 in hydrocarbon solvents, "SNi" reactions lead mainly to exo- (4g) and endo-2-chloro-5-norbornenes (4g′). Leakage to ion pairs adds ～16% of nortricyclyl chloride 3g. In more polar solvents, the main product remains chloride 4g, but increasing quantities of 3g appear due to enhanced participation of ion pairs. Fragmentations of 5 and 6 in MeOH afford chlorides 3g and 4g as well as the corresponding methyl ethers 3b and 4b. Nortricyclyl cation and norbornenyl cation chloride anion pairs and methanol-solvated nortricyclyl cations are invoked to rationalize the results.