Phosphorus tribromide → HCID 23043711, compound
Reaction equation
[CH3:1][O:2][C:3]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[S:5][C:4]=1[CH:12]=O.[BH4-].[Na+].P(Br)(Br)[Br:17]>C(O)C.CCOCC>[Br:17][CH2:12][C:4]1[S:5][C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[C:3]=1[O:2][CH3:1]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
To a solution of 3-methoxybenzothiophene-2-carboxaldehyde [3.4 g; J. Chem. Soc. C 779 (1967)] in ethanol (60 ml) was added sodium borohydride (0.34 g). After 10 minutes the solution was poured onto water (200 ml) and extracted with ether (2×50 ml). The ether extracts were washed with water (2×25 ml), dried and then evaporated to the title product as an orange oil. Yield, 3.4 g. 'HNMR (CDCl3, 60 MHz): 2.6 (s, 1H), 3.8 (s, 3H), 4.8 (s, 2H), 7.0-8.0 (m, 4H). This material (1.5 g) was dissolved in ether (20 ml). To the solution cooled in an ice-bath was added phosphorous tribromide (0.7 ml). The mixture was let to stand for 1 hour. The reaction mixture was poured onto ice-water (50 ml) and the ether layer separated, collected, dried and evaporated to obtain the title product as a light yellow oil (yield, 1.4 g). 'HNMR CDCl3, 60 MHz): 4.0 (s, 3H), 5.0 (s, 2H), 7.2-7.8 (m, 4H).
Workup
- additionAfter 10 minutes the solution was poured onto water (200 ml)
- extractionextracted with ether (2×50 ml)
- washThe ether extracts were washed with water (2×25 ml)
- customdried
- customevaporated to the title product as an orange oil
- customYield
- temperatureTo the solution cooled in an ice-bath
- additionThe reaction mixture was poured onto ice-water (50 ml)
- customthe ether layer separated
- customcollected
- customdried
- customevaporated
Sources & evidence
- ORD record
- ord-5f09bf94869544988a0a6a89f64edacf
- Source dataset
- uspto-grants-1990_07
- Patent number
- US04939140
Reaction notes
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