Hydrogen Sulfide → 1,9-dimethyl-10H-phenothiazine

HRID 1626232

Reaction equation

HRID 1626232 reaction equation
[C:1]1([CH3:15])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[CH3:14].[S].II.[SH2:19]>>[CH3:14][C:9]1[C:8]2[NH:7][C:2]3[C:3](=[CH:4][CH:5]=[CH:6][C:1]=3[CH3:15])[S:19][C:13]=2[CH:12]=[CH:11][CH:10]=1

Participants

5

Reactant 4

HCID 402Hydrogen SulfideHCID 807IodineHCID 136423Benzenamine, 2-methyl-N-(2-methylphenyl)-HCID 5362487Sulfur

Product 1

HCID 674644911,9-dimethyl-10H-phenothiazineYield 28%

Conditions

Temperature
210 °C

Procedure

Put di(2-tolyl)amine (11.7 g, 59.3 mmol) in a 3-neck 100 mL round-bottom flask. Added elemental sulfur (3.9 g, 121.65 mmol, 2 eq.), crushed iodine (0.44 g, 1.73 mmol, 3 mol %), then o-dichlorobenzene (22 mL). Added an outlet to a dilute bleach solution (for hydrogen sulfide evolution) then put under argon. Refluxed at 180° C. for 4 h. Remove solvent under reduced pressure. Purified with Isco column chromatography using 2% ethyl acetate/98% hexane. Obtained product as white crystals (2 g, 8.8 mmol, 15% yield). Alternatively, put di(2-tolyl)amine (either purified or impure from the aforementioned reaction; 8.9525 g, 45.3 mmol) in a round bottom flask. Added elemental sulfur (2.98 g, 92.9 mmol, 2 eq.) then crushed iodine (3.28 g, 12.9 mmol, 28% mol). Added an outlet to a dilute bleach solution (for hydrogen sulfide) then put under argon. Stirred at 210° C. for 30 min or until no starting material was present by LC/MS. Allowed the reaction cool to about 60° C. then add hexane for extraction. Repeat hot hexane extractions (at least one overnight; minimum time of half an hour for each extraction) of reaction until product was no longer seen in residue (about 4 times). Combined hexane extractions and concentrate in vacuo. Purified resulting residue either through repeated repeated hot hexane/ethanol or isopropanal crystallizations, hot acetone/isopropanol crystallizations (or triturations) or Isco column chromatography using 2% ethyl acetate/98% hexane to obtain product as white crystals (2.92 g, 12.8 mmol, 28% yield).

Workup

  1. custompurified
  2. customimpure from the aforementioned reaction
  3. temperatureAllowed the reaction cool to about 60° C.
  4. extractionadd hexane for extraction
  5. extractionhexane extractions (at least one overnight
  6. extractionminimum time of half an hour for each extraction)
  7. customof reaction until product
  8. extractionCombined hexane extractions
  9. concentrationconcentrate in vacuo
  10. customPurified
  11. customresulting residue
  12. customhexane/ethanol or isopropanal crystallizations, hot acetone/isopropanol crystallizations (or triturations) or Isco column chromatography

Sources & evidence

ORD record
ord-f10e6d870aed4b00ba6e45ba932ed2ef
Source dataset
uspto-grants-2014_07
Patent number
US08785434B2

Linked notes

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