3721-19-5

Basic information

• Product Name: 5-chlorobicyclo[2.2.1]hept-2-ene
• CAS NO: 3721-19-5
• Molecular Formula: C₇H₉Cl
• Molecular Weight: 128.5994
• Mol File: 3721-19-5.mol
• Article Data: 3

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(3721-19-5)
• EPA Substance Registry System: 5-chlorobicyclo[2.2.1]hept-2-ene(3721-19-5)

Safety Data

• Hazardous Substances Data: 3721-19-5(Hazardous Substances Data)

Usage

General Description

5-Chlorobicyclo[2.2.1]hept-2-ene is a chemical compound with the molecular formula C7H9Cl. It is a bicyclic organic compound containing a ring of seven carbon atoms and one chlorine atom. 5-chlorobicyclo[2.2.1]hept-2-ene is a colorless liquid with a strong, pungent odor. It is primarily used as an intermediate in the synthesis of other chemical compounds, such as pharmaceuticals and agrochemicals. 5-Chlorobicyclo[2.2.1]hept-2-ene is also used as a reagent in organic synthesis and as a solvent in various industrial processes. It is important to handle this compound with caution, as it can be irritating to the skin, eyes, and respiratory system.

Upstream product

• 740804-80-2 3-((1R,4S,7R)-Bicyclo[2.2.1]hept-2-en-7-yloxy)-3-chloro-3H-diazirine 
• 75-01-4 chloroethylene 
• 542-92-7 cyclopenta-1,3-diene 
• 694-97-3 endo-5-norbornen-2-ol 

Downstream Products

• 498-66-8 norborn-2-ene 
• 279-19-6 nortricyclane 
• 21942-28-9 3-nortricyclyltrimethyltin 
• 21957-51-7 endo-2-norbornene-5-yl-trimethyl tin 

Relevant articles and documents

Endo entry to the nortricyclyl-norbornenyl cation system: Stereochemistry in the fragmentation of endo-5-norbornenyl-2-oxychlorocarbene

Fragmentation of (S)-endo-5-norbornenyl-2-oxychlorocarbene [(S)-8] in cyclohexane-d12 gives ～20% (S)-endo-2-chloro-5-norbornene [(S)-7] with ～50% ee, 65-70% (R)-exo-2-chloro-5-norbornene [(R)-4] with >95% ee, and ～12% (R)-3-nortricyclyl chloride [(R)-5] with ～22% ee. (Analogous stereochemical results were also obtained starting with the enantiomeric carbene (R)-8.) The (S)-8 to (S)-7 and (S)-8 to (R)-4 conversions are ascribed mainly to retention and inversion SNi transition states, respectively. These have been located by computational methods and are nearly isoenergetic. In more polar solvents (CDCl3 and CD3CN), the fragmentation of (S)-8 increasingly occurs via competitive ion pair pathways in which steroselectivity is diminished, and escape to the norbornenyl-nortricyclyl cation directs the products away from endo-2-chloro-5-norbornene toward exo-chloride 4 and nortricyclyl chloride 5.

Unexpected interconnection of the 7-norbornenyl and 3-nortricyclcyl/5- norbornen-2-yl cations

Fragmentation of syn-7-norbornenyloxychlorocarbene provides products derived from both 7-norbornenyl cation-chloride anion pairs and from 3-nortricyclyl/2-norbornen-5-yl cation-chloride anion pairs. A 5,7-hydride shift within the 7-norbornenyl cation is proposed to interconnect the two cation systems.