Potassium Carbonate → 6,7-Difluorobenzo[B]thiazolo[3,4-D][1,4]oxazine-1(4H)-thione
Reaction equation
[OH:1][CH2:2][C:3]1[N:4]([C:9]2[CH:14]=[CH:13][C:12]([F:15])=[C:11]([F:16])[C:10]=2F)[C:5](=[S:8])[S:6][CH:7]=1.C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O>[F:16][C:11]1[C:10]2[O:1][CH2:2][C:3]3=[CH:7][S:6][C:5](=[S:8])[N:4]3[C:9]=2[CH:14]=[CH:13][C:12]=1[F:15]Participants
4
Conditions
- Temperature
- 110 °C
Procedure
4-Hydroxymethyl-3-(2,3,4-trifluorophenyl)-2(3H)-thiazolethione (60 g) prepared in the same manner as in Reference Example 19 was dissolved in N,N-dimethylformamide (450 ml) and thereto potassium carbonate (60 g) was added and the mixture was stirred at 110° C. for 3 hours. After the reaction mixture was evaporated to dryness, water was added to the residue and the resultant was extracted with chloroform. The extract was washed with a NaCl solution and dried over anhydrous sodium sulfate, followed by distilling off the solvent under reduced pressure. The residue was recrystallized from a mixed solvent of hexane-ethyl acetate to give the title compound (51 g) as pale yellow crystals, m.p. 163°-167° C.
Workup
- customAfter the reaction mixture was evaporated to dryness, water
- additionwas added to the residue
- extractionthe resultant was extracted with chloroform
- washThe extract was washed with a NaCl solution
- dry with materialdried over anhydrous sodium sulfate
- distillationby distilling off the solvent under reduced pressure
- customThe residue was recrystallized from a mixed solvent of hexane-ethyl acetate
Sources & evidence
- ORD record
- ord-7d9bad2b75514244a5586a0d16e8d691
- Source dataset
- uspto-grants-1989_08
- Patent number
- US04853469
Reaction notes
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