Sulfuryl chloride → 4-(methoxycarbonyl)-2-methylthiophen-3-aminium chloride
Reaction equation
[NH2:1][C:2]1[CH:6]([CH3:7])[S:5][CH2:4][C:3]=1[C:8]([O:10][CH3:11])=[O:9].S(Cl)([Cl:15])(=O)=O>C(Cl)Cl>[ClH:15].[NH2:1][C:2]1[C:3]([C:8]([O:10][CH3:11])=[O:9])=[CH:4][S:5][C:6]=1[CH3:7]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -10 °C
Procedure
11.5 g of methyl 4-amino-5-methyl-2,5-dihydrothiophene-3-carboxylate (2) (60 mmol, content: 90%) were dissolved in 25 ml of CH2Cl2 and cooled to −10° C. A solution of 8.9 g of sulfuryl chloride (66 mmol) in 10 ml of CH2Cl2 in the temperature range of −10-0° C. was added dropwise to this solution over a period of 2 h. The reaction mixture was subsequently stirred at −10-0° C. for another 1 h and then warmed to room temperature. For workup, the reaction mixture was concentrated under reduced pressure. 14.7 g of methyl 4-amino-5-methylthiophene-3-carboxylate hydrochloride (5) were obtained (89% of theory, content: 62.5%, determined as the free amine).
Workup
- temperaturewarmed to room temperature
- concentrationFor workup, the reaction mixture was concentrated under reduced pressure
Sources & evidence
- ORD record
- ord-62932e35e07040d791206c3e1f0d72a1
- Source dataset
- uspto-grants-2011_04
- Patent number
- US07923571B2
Reaction notes
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