Hydrochloric Acid → HCID 19994931, compound
Reaction equation
[I-].[CH3:2][N:3]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5]([C:12]2[S:13][CH:14]=[C:15]([C:17]3[CH:18]=[N+:19]([CH3:23])[CH:20]=[CH:21][CH:22]=3)[N:16]=2)=[CH:4]1.[BH4-].[Na+].[H][H].[ClH:28]>C(O)C.O>[ClH:28].[CH3:2][N:3]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5]([C:12]2[S:13][CH:14]=[C:15]([C:17]3[CH2:18][NH+:19]([CH3:23])[CH2:20][CH2:21][CH:22]=3)[N:16]=2)=[CH:4]1Participants
Procedure
3-[2-(1-Methylindol-3-yl)-1,3-thiazol-4-yl]-1-methylpyridinium iodide (0.8 g) was suspended in ethanol (20 ml) and Water (1 ml). Sodium borohydride (0.1g) was added in portions with much evolution of hydrogen. After 30 minutes the intense yellow coloration was replaced by a light brown hue. 5M Hydrochloric acid was added dropwise to quench excess sodium borohydride. The contents of the flask were poured onto a saturated solution of sodium bicarbonate which was extracted with dichloromethane (4×150 ml). This was washed with brine, dried (MgSO4) and evaporated under reduced pressure. The residue was purified by column chromatography on silica using 10% methanol in dichloromethane as eluant yielding 0.4 g. This was further purified by dissolving in methanol; addition of methanolic HCl (20 ml) precipitated the hydrochloride as a yellow powder. This was recrystallised from aqueous ethanol, m.p. 235° C. (dec). δH 2.6-2.8 (2 H, m, β-pyr), 3.08 (3 H, s, NMe pyr), 3.16-3.28 (1 H, m, α-pyr), 3.65 (1 H, mc, γ-pyr), 3.74 (1 H, d, J=15.6 Hz, H-1 α-pyr), 4.14 (1 H, d, J=15.6 Hz, H-1 α-pyr), 6.53 (1 H, mc, H-4 γ-pyr), 7.09 (1 H, s, SCH), 7.23 and 7.30 (2 H, 2×t, J=7.9 Hz, H-5 and H-6), 7.37 (1 H, d, J=7.9 Hz), 7.53 (1 H, d, J=7.8 Hz), 7.75 (1 H, s, H-2); m/z 309 (M+ free base, 100%), 265 (40 ), 168 (40), 96 (35).
Workup
- customto quench excess sodium borohydride
- additionThe contents of the flask were poured onto a saturated solution of sodium bicarbonate which
- extractionwas extracted with dichloromethane (4×150 ml)
- washThis was washed with brine
- dry with materialdried (MgSO4)
- customevaporated under reduced pressure
- customThe residue was purified by column chromatography on silica using 10% methanol in dichloromethane as eluant
- customyielding 0.4 g
- customThis was further purified
- dissolutionby dissolving in methanol
- additionaddition of methanolic HCl (20 ml)
- customprecipitated the hydrochloride as a yellow powder
- customThis was recrystallised from aqueous ethanol, m.p. 235° C. (dec)
Sources & evidence
- ORD record
- ord-3e4ee95b45e443e8b869b04a49c5672a
- Source dataset
- uspto-grants-1991_08
- Patent number
- US05041456
Reaction notes
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