Isopropanol → (RS)-3-(2-Dimethylaminopropyl)2-imino-6-trifluoromethoxybenzothiazoline
Reaction equation
[NH2:1][C:2]1[S:3][C:4]2[CH:10]=[C:9]([O:11][C:12]([F:15])([F:14])[F:13])[CH:8]=[CH:7][C:5]=2[N:6]=1.Cl.Cl[CH:18](C)[CH2:19][N:20]([CH3:22])[CH3:21].[CH3:24]C(O)C>>[CH3:21][N:20]([CH3:22])[CH:19]([CH3:24])[CH2:18][N:6]1[C:5]2[CH:7]=[CH:8][C:9]([O:11][C:12]([F:15])([F:13])[F:14])=[CH:10][C:4]=2[S:3][C:2]1=[NH:1]Participants
Procedure
2-Amino-6-trifluoromethoxybenzothiazole (9.4 g) and 2-chloro-1-dimethylaminopropane hydrochloride (7.0 g) are heated for 1 hour to 130.C. 2-Propanol (20 cc) is added and heating is continued for 24 hours to boiling. After cooling of the mixture to a temperature in the region of 20.C, the precipitate is filtered off and then treated with IN sodium hydroxide (80 cc) in distilled water (100 cc). The residue obtained by extraction with dichloromethane, drying over magnesium sulphate and concentration to dryness under reduced pressure (20 mm Hg; 2.7 kPa) is purified by chromatography on a silica column with a mixture of ethyl acetate and methanol (80:20 by volume) as eluent. (RS)-3-(2-Dimethylaminopropyl)2-imino-6-trifluoromethoxybenzothiazoline (3.3 g) is obtained in the form of a yellow oil, which is converted to a dihydrochloride subliming at about 190° C.
Workup
- temperatureheating
- filtrationthe precipitate is filtered off
- additiontreated with IN sodium hydroxide (80 cc) in distilled water (100 cc)
- customThe residue obtained by extraction with dichloromethane
- dry with materialdrying over magnesium sulphate and concentration to dryness under reduced pressure (20 mm Hg; 2.7 kPa)
- customis purified by chromatography on a silica column with a mixture of ethyl acetate and methanol (80:20 by volume) as eluent
Sources & evidence
- ORD record
- ord-a1a7b94c320d4280a5278aaecd1f3e22
- Source dataset
- uspto-grants-1991_06
- Patent number
- US05026717
Reaction notes
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