Hydrochloric Acid → 10-Methylphenothiazine-4-carbaldehyde

HRID 2395158Notes

Reaction equation

HRID 2395158 reaction equation
C([Li])(C)(C)C.[CH3:6][N:7]1[C:20]2[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=2[S:14][C:13]2[C:8]1=[CH:9][CH:10]=[CH:11][CH:12]=2.CN(C)CCN(C)C.[CH:29](N1CCCCC1)=[O:30].Cl>C(OCC)C>[CH3:6][N:7]1[C:8]2[CH:9]=[CH:10][CH:11]=[C:12]([CH:29]=[O:30])[C:13]=2[S:14][C:15]2[C:20]1=[CH:19][CH:18]=[CH:17][CH:16]=2

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 8037N,N,N',N'-TetramethylethylenediamineHCID 174291-PiperidinecarboxaldehydeHCID 7101510-MethylphenothiazineHCID 178418306HCID 178418306, compound

Product 1

HCID 381215410-Methylphenothiazine-4-carbaldehydeYield 74.4%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

21.7 ml of tert-butyllithium solution (1.4M in pentane) were slowly added dropwise under argon at -78° to a solution of 5.0 g (23.4 mmol) of 10-methylphenothiazine in 10 ml of absolute diethyl ether and 7 ml of freshly distilled N,N,N',N'-tetramethylethylenediamine. The reaction mixture was subsequently brought slowly to room temperature, stirred for 18 hours, then cooled to 0° and thereupon treated with 3.90 ml (35.1 mmol) of N-formylpiperidine. The reaction mixture was stirred at room temperature for 2 hours and then poured into 50 g of ice, 50 ml of 0.1N aqueous hydrochloric acid solution and 1.50 ml of diethyl ether. The aqueous phase was extracted twice with 100 ml of diethyl ether and the combined organic fractions were dried over magnesium sulphate and concentrated. The residue was chromatographed on 500 g of silica gel with ethyl acetate/hexane (1:3), whereafter, after recrystallization from ethyl acetate/hexane, 4.20 g (74.4%) of 10-methyl-phenothiazine-4-carbaldehyde were obtained as a yellow solid of m.p. 103°.

Workup

  1. customwas subsequently brought slowly to room temperature
  2. temperaturecooled to 0°
  3. stirringThe reaction mixture was stirred at room temperature for 2 hours
  4. extractionThe aqueous phase was extracted twice with 100 ml of diethyl ether
  5. dry with materialthe combined organic fractions were dried over magnesium sulphate
  6. concentrationconcentrated
  7. customThe residue was chromatographed on 500 g of silica gel with ethyl acetate/hexane (1:3)
  8. customwhereafter, after recrystallization from ethyl acetate/hexane

Sources & evidence

ORD record
ord-76ef5bc5053f4c02bd77d504345f72d8
Source dataset
uspto-grants-1998_09
Patent number
US05811548

Reaction notes

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