Ethyl Acetate → 2-(3,3-diethoxypropyl)-3,4-dihydro-2-(3,4-dimethoxyphenyl)-4-methyl-3-oxo-2H-1,4-benzothiazine

HRID 649330

Reaction equation

HRID 649330 reaction equation
[H-].[Na+].[CH3:3][O:4][C:5]1[CH:6]=[C:7]([CH:13]2[C:18](=[O:19])[N:17]([CH3:20])[C:16]3[CH:21]=[CH:22][CH:23]=[CH:24][C:15]=3[S:14]2)[CH:8]=[CH:9][C:10]=1[O:11][CH3:12].[CH2:25]([O:27][CH:28]([O:32][CH2:33][CH3:34])[CH2:29][CH2:30]Cl)[CH3:26].C(OCC)(=O)C>CN(C)C=O.O>[CH2:25]([O:27][CH:28]([O:32][CH2:33][CH3:34])[CH2:29][CH2:30][C:13]1([C:7]2[CH:8]=[CH:9][C:10]([O:11][CH3:12])=[C:5]([O:4][CH3:3])[CH:6]=2)[C:18](=[O:19])[N:17]([CH3:20])[C:16]2[CH:21]=[CH:22][CH:23]=[CH:24][C:15]=2[S:14]1)[CH3:26]

Participants

7

Reactant 4

HCID 8857Ethyl AcetateHCID 24758Sodium hydrideHCID 962173-Chloro-1,1-diethoxypropaneHCID 14244692HCID 14244692, compound

Product 1

HCID 201430342-(3,3-diethoxypropyl)-3,4-dihydro-2-(3,4-dimethoxyphenyl)-4-methyl-3-oxo-2H-1,4-benzothiazineYield 71.5%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent2×

Procedure

To a stirred suspension of 60% sodium hydride (0.6 g) in dimethylformamide (5 ml), 3,4-dihydro-2-(3,4-dimethoxyphenyl)-4-methyl-3-oxo-2H-1,4-benzothiazine (4.4 g) dissolved in dimethylformamide (15 ml) is added under nitrogen atmosphere and ice-cooling, and the mixture is stirred for 15 minutes at room temperature. β-Chloropropionaldehyde diethyl acetal (2.8 g) is added to the reaction mixture, and the mixture is stirred for 2.5 hours at 60° C. The mixture is poured into a mixture of ethyl acetate and water. The organic layer is washed with 1N sodium hydroxide and saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue is purified by silica gel column chromatography to give 4.4 g (71.5 %) of 2-(3,3-diethoxypropyl)-3,4-dihydro-2-(3,4-dimethoxyphenyl)-4-methyl-3-oxo-2H-1,4-benzothiazine as an oily form (compound No. 36, (IR: neat, cm-1) 1660, 1588, 1444, 1325, 1238, 750).

Workup

  1. additionis added under nitrogen atmosphere
  2. temperatureice-cooling
  3. stirringthe mixture is stirred for 2.5 hours at 60° C
  4. washThe organic layer is washed with 1N sodium hydroxide and saturated aqueous sodium chloride solution
  5. dry with materialdried over anhydrous sodium sulfate
  6. concentrationconcentrated in vacuo
  7. customThe residue is purified by silica gel column chromatography

Sources & evidence

ORD record
ord-ad637bf96dca4005bd7f8a8efee8d099
Source dataset
uspto-grants-1988_04
Patent number
US04739050

Linked notes

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