Hydrochloric Acid → HCID 19994931, compound

HRID 1710106Notes

Reaction equation

HRID 1710106 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]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 4311764Sodium borohydrideHCID 14810920HCID 14810920, compoundHCID 178418361HCID 178418361, compound

Product 1

HCID 19994931HCID 19994931, compound

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

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 (0.1 g) 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 (2H, m, β-pyr), 3.08 (3H, s, NMe pyr), 3.16-3.28 (1H, m, α-pyr), 3.65 (1H, mc, α-pyr), 3.74 (1H, d, J=15.6 Hz, H-1 α-pyr), 4.14 (1H, d, J=15.6 Hz, H-1 α-pyr), 6.53 (1H, mc, H-4 γ-pyr), 7.09 (1H, s, SCH), 7.23 and 7.30 (2H, 2×t, J=7.9 Hz, H-5 and H-6), 7.37 (1H, d, J=7.9 Hz), 7.53 (1H, d, J=7.8 Hz), 7.75 (1H, s, H-2); m/z 309 (M+ free base, 100%), 265 (40), 168 (40), 96 (35 ).

Workup

  1. customto quench excess sodium borohydride
  2. additionThe contents of the flask were poured onto a saturated solution of sodium bicarbonate which
  3. extractionwas extracted with dichloromethane (4×150 ml)
  4. washThis was washed with brine
  5. dry with materialdried (MgSO4)
  6. customevaporated under reduced pressure
  7. customThe residue was purified by column chromatography on silica using 10% methanol in dichloromethane as eluant
  8. customyielding 0.4 g
  9. customThis was further purified
  10. dissolutionby dissolving in methanol
  11. additionaddition of methanolic HCl (20 ml)
  12. customprecipitated the hydrochloride as a yellow powder
  13. customThis was recrystallised from aqueous ethanol, m.p. 235° C. (dec)

Sources & evidence

ORD record
ord-17df88017b9148ec9d3a631d447a149c
Source dataset
uspto-grants-1990_08
Patent number
US04952587

Reaction notes

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