Allyl chloride → 2,3-Dihydro-2,5-dimethyl-4-chloro-7-nitrobenzofuran
Reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([OH:12])[C:5]([N+:9]([O-:11])=[O:10])=[CH:6][C:7]=1[CH3:8].[OH-].[Na+].Cl[CH2:16][CH:17]=[CH2:18]>CS(C)=O>[CH3:16][CH:17]1[CH2:18][C:3]2[C:2]([Cl:1])=[C:7]([CH3:8])[CH:6]=[C:5]([N+:9]([O-:11])=[O:10])[C:4]=2[O:12]1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 190 °C
Procedure
A mixture of 93.4 g of 2B, 750 ml of DMSO, 48 g of 50% aqueous sodium hydroxide and 45.9 g of 3-chloropropene was stirred for 8 hours at 75°-80° C., then for 16 hours at room temperature, The resulting mixture was added to 3 liters of ice water and the resulting mixture was extracted with methylene chloride. The extract was washed with water, dried (MgSO4) and evaporated to dryness. The residue, in a nitrogen atmosphere, was heated slowly to 190° C. (one hour) and held at 185°-195° C. for two hours, cooled to room temperature, and dissolved in 250 ml of acetic acid. 150 ml of 48% aqueous hydrogen bromide solution was added. The mixture was stirred at reflux for three hours, then mixed with 2 liters of ice water, and the resulting mixture was extracted with a 1:1 v:v mixture of hexane and ether. The extract was washed with water, 5 % aqueous sodium bicarbonate solution, dried (MgSO4), charcoaled and concentrated to dryness. The residue was crystallized from 500 ml of 9:1 v:v hexane/ether mixture, giving 2,3-dihydro-2,5-dimethyl-4-chloro-7-nitrobenzofuran (2C), m.p.: 114°-116° C.
Workup
- waitfor 16 hours at room temperature
- extractionthe resulting mixture was extracted with methylene chloride
- washThe extract was washed with water
- dry with materialdried (MgSO4)
- customevaporated to dryness
- waitheld at 185°-195° C. for two hours
- temperaturecooled to room temperature
- dissolutiondissolved in 250 ml of acetic acid
- addition150 ml of 48% aqueous hydrogen bromide solution was added
- stirringThe mixture was stirred
- temperatureat reflux for three hours
- additionmixed with 2 liters of ice water
- extractionthe resulting mixture was extracted with a 1:1 v
- additionv mixture of hexane and ether
- washThe extract was washed with water, 5 % aqueous sodium bicarbonate solution
- dry with materialdried (MgSO4)
- concentrationconcentrated to dryness
- customThe residue was crystallized from 500 ml of 9:1 v
Sources & evidence
- ORD record
- ord-2a23fa9908f942169cb9fde691fb0c34
- Source dataset
- uspto-grants-1986_03
- Patent number
- US04577011
Reaction notes
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