Chlorosuccinimide → HCID 14330450, compound
Reaction equation
[CH3:1][O:2][C:3]1[C:12]2[S:11][CH2:10][CH:9](C(O)=O)[CH2:8][C:7]=2[CH:6]=[CH:5][CH:4]=1.ClN1C(=[O:22])CCC1=O>C(Cl)Cl>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][CH:6]=[C:7]2[C:12]=1[S:11][CH2:10][C:9](=[O:22])[CH2:8]2Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of 10 g of 8-methoxy-3,4-dihydro-2H-[1]-benzothiopyran-3-carboxylic acid in 200 ml of methylene chloride is added 6.2 g of N-chlorosuccinimide in portions. After 10 minutes 60 g of silica gel is added. The reaction mixture is stirred for 15 minutes, filtered through 40 g of silica gel eluting with ether/methylene chloride (1:1). The solvent is concentrated to 100 ml, 5 ml of triethylamine and 5 g of ethyl chloroformate are added. After concentration 5 g of sodium azide in 60 ml of dimethylformamide are added and the reaction mixture is stirred for 1 hour. After dilution with water the products are extracted with ether, the ether extract is dried and evaporated to dryness; 150 ml of 10% aqueous sulfuric acid is added and the reaction mixture is heated under reflux for 2 hours. The reaction mixture is extracted with ether, the ether extract is washed with dilute sodium bicarbonate solution, dried and evaporated to dryness. Crystallization from methanol affords 8-methoxythiochroman-3-one, m.p. 60°.
Workup
- additionAfter 10 minutes 60 g of silica gel is added
- filtrationfiltered through 40 g of silica gel eluting with ether/methylene chloride (1:1)
- concentrationThe solvent is concentrated to 100 ml, 5 ml of triethylamine and 5 g of ethyl chloroformate
- additionare added
- additionAfter concentration 5 g of sodium azide in 60 ml of dimethylformamide are added
- stirringthe reaction mixture is stirred for 1 hour
- extractionAfter dilution with water the products are extracted with ether
- extractionthe ether extract
- customis dried
- customevaporated to dryness
- addition150 ml of 10% aqueous sulfuric acid is added
- temperaturethe reaction mixture is heated
- temperatureunder reflux for 2 hours
- extractionThe reaction mixture is extracted with ether
- extractionthe ether extract
- washis washed with dilute sodium bicarbonate solution
- customdried
- customevaporated to dryness
- customCrystallization from methanol
Sources & evidence
- ORD record
- ord-5223da355aa44519bd35112322d79764
- Source dataset
- uspto-grants-1986_08
- Patent number
- US04604397
Reaction notes
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