Methanol → 2-Methoxy-5-(5-thioxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid methyl ester
Reaction equation
[CH3:1][O:2][C:3]1[CH:11]=[CH:10][C:9]([N:12]2[C:16](=[S:17])[NH:15][N:14]=[CH:13]2)=[CH:8][C:4]=1[C:5]([OH:7])=[O:6].S(Cl)(Cl)=O.[CH3:22]O>>[CH3:22][O:6][C:5](=[O:7])[C:4]1[CH:8]=[C:9]([N:12]2[C:16](=[S:17])[NH:15][N:14]=[CH:13]2)[CH:10]=[CH:11][C:3]=1[O:2][CH3:1]Participants
4
Procedure
Treat a solution of 2-methoxy-5-(5-thioxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid (6.66 g, 26.5 mmol) and methanol (80 mL) under argon via syringe dropwise with thionyl chloride (2.9 mL, 40 mmol). Stir for three days and remove the methanol in vacuo. Purify the residue by flash chromatography (silica gel, 9.5×12.7 cm) eluting with 40% ethyl acetate in dichloromethane and then with ethyl acetate. Concentrate the desired fractions in vacuo to afford 4.55 g of 2-methoxy-5-(5-thioxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid methyl ester.
Workup
- customremove the methanol in vacuo
- customPurify the residue by flash chromatography (silica gel, 9.5×12.7 cm)
- washeluting with 40% ethyl acetate in dichloromethane
- concentrationConcentrate the desired fractions in vacuo
Sources & evidence
- ORD record
- ord-80486af1dfb54d0e8beef22ef7b4be3c
- Source dataset
- uspto-grants-2002_07
- Patent number
- US06423704B1
Reaction notes
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