Acetic Anhydride → 1-(3,7-bis(dimethylamino)-10H-phenothiazin-10-yl)ethanone

HRID 705496Notes

Reaction equation

HRID 705496 reaction equation
O.[NH2:2]N.C[CH2:5][N:6]([CH:10]([CH3:12])[CH3:11])[CH:7](C)C.O.O.O.[Cl-].[CH3:17][C:18]1[SH+:19][CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=[CH:25][CH:26]=1.O.NN.[C:30]([O:33]C(=O)C)(=O)[CH3:31].C[CH2:38][N:39]([CH:43](C)C)C(C)C>C(#N)C>[CH3:38][N:39]([CH3:43])[C:25]1[CH:24]=[CH:23][C:17]2[N:2]([C:30](=[O:33])[CH3:31])[C:21]3[C:20]([S:19][C:18]=2[CH:26]=1)=[CH:12][C:10]([N:6]([CH3:5])[CH3:7])=[CH:11][CH:22]=3

Participants

7

Reactant 5

HCID 7918Acetic AnhydrideHCID 24654Hydrazine hydrate (1:1)HCID 81531DiisopropylethylamineHCID 866280322-Methylthionin-1-ium;chloride;trihydrateHCID 86628034hydrazine monohydrate Hunig's base

Product 1

HCID 198258321-(3,7-bis(dimethylamino)-10H-phenothiazin-10-yl)ethanoneYield 65%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
25 °C

Procedure

Synthesis using hydrazine monohydrate/Hunig's base in one pot. To a 250 cm3 round bottom flask under an atmosphere of nitrogen was added methylthioninium chloride trihydrate (80.2 mmol, 30 g) and acetonitrile (150 cm3). Hydrazine monohydrate (176.5 mmol, 8.84 g) was added and the mixture was heated to reflux and stirred for 10 minutes before cooling to 25° C. The yellow/green suspension had acetic anhydride (794 mmol, 81.2 g) and Hunig's base (diisopropylethylamine) (232 mmol, 29.97 g) added. The mixture was heated at 90° C. for 2 hours. The cooled mixture was then poured carefully into ice water (400 cm3) in ten equal portions while stirring to give a precipitate. The precipitate was stirred for 30 minutes before it was filtered, washed with water (3×100 cm3), and air dried for 30 minutes. The crude material was crystallised from hot ethanol (400 cm3) to yield the title compound (17.15 g, 65%) as a light grey solid. Mp 137° C.; vmax(KBr)/cm−1 2910 (CH), 2876 (CH), 2856 (CH), 2799 (CH), 1659 (C═O), 1596 (NO2), 1502 (NO2); δH (250 MHz; CDCl3) 2.16 (3H, s, CH3), 2.93 (12H, s, NCH3), 6.59-6.62 (2H, d, J8.5, ArH), 6.69-6.71 (2H, d, J2.75, ArH), 7.08-7.47 (2H, brd s, ArH); δC (62.9 MHz; CDCl3) 170.3 (C═O), 148.9 (ArC), 127.2 (ArC), 127.1 (ArC), 127.0 (ArC), 110.9 (ArC), 110.7 (ArC), 40.7 (NCH3), 22.9 (CH3); m/z (ES) 284.2 (100%, [M−OAc]+), 328.1 (15%, [M+H]+), 350.1 (41%, [M+Na]+).

Workup

  1. customSynthesis
  2. temperaturethe mixture was heated
  3. temperatureto reflux
  4. additionadded
  5. temperatureThe mixture was heated at 90° C. for 2 hours
  6. stirringwhile stirring
  7. customto give a precipitate
  8. stirringThe precipitate was stirred for 30 minutes before it
  9. filtrationwas filtered
  10. washwashed with water (3×100 cm3), and air
  11. customdried for 30 minutes
  12. customThe crude material was crystallised from hot ethanol (400 cm3)

Sources & evidence

ORD record
ord-742ffef05ef645d58233368dce910468
Source dataset
uspto-grants-2015_11
Patent number
US09174954B2

Reaction notes

Loading…