Water → 2,3,4,5-Tetrahydrobenzo[F][1,4]thiazepine 1,1-dioxide
Reaction equation
[O:1]=[S:2]1(=[O:16])[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[CH2:6][N:5](C(=O)C)[CH2:4][CH2:3]1.[OH-].[Na+].O>C(O)C>[S:2]1(=[O:16])(=[O:1])[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[CH2:6][NH:5][CH2:4][CH2:3]1Participants
Procedure
To a solution of 1-(1,1-dioxido-2,3-dihydro-1,4-benzothiazepin-4(5H)-yl)ethanone (240 g, 1.0 mol) in ethanol (1.0 L) was added sodium hydroxide (200 g, 5.0 mol) and water (700 mL). The mixture was refluxed overnight and then concentrated in vacuo. The residue was extracted by ethyl acetate (1500 mL×4). The combined organic layers were extracted by hydrochloric acid (2000 mL, 3 N). The acidic aqueous layer was washed with ethyl acetate (1500 mL×2), then basified with a saturated aqueous solution of sodium bicarbonate to pH >7, and extracted with ethyl acetate (1500 mL×4). The combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo to afford 151 g of 2,3,4,5-tetrahydro-1,4-benzothiazepine 1,1-dioxide (yield was 76%), MS obsd. (ESI+) [(M+H)1] 198, 1H NMR (400 MHz, DMSO-d6) δ ppm 7.89 (dd, J=1.2, 7.6 Hz, 1 H), 7.56 (t, J=7.6 Hz, 1 H), 7.47 (t, J=7.6 Hz, 1 H), 7.42 (d, J=7.6 Hz, 1 H), 4.04 (s, 2 H), 3.32-3.30 (m, 2 H), 3.30-3.25 (m, 2 H), 2.64 (s, 1 H).
Workup
- temperatureThe mixture was refluxed overnight
- concentrationconcentrated in vacuo
- extractionThe residue was extracted by ethyl acetate (1500 mL×4)
- extractionThe combined organic layers were extracted by hydrochloric acid (2000 mL, 3 N)
- washThe acidic aqueous layer was washed with ethyl acetate (1500 mL×2)
- extractionextracted with ethyl acetate (1500 mL×4)
- dry with materialThe combined organic layers were dried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
Sources & evidence
- ORD record
- ord-38b319814cff4deea20beb02c4253bac
- Source dataset
- uspto-grants-2014_10
- Patent number
- US08871756B2
Reaction notes
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