Lithium Hydroxide → 3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carbaldehyde

HRID 885668Notes

Reaction equation

HRID 885668 reaction equation
[O:1]=[C:2]1[NH:7][C:6]2[CH:8]=[C:9]([C:12](O)=[O:13])[CH:10]=[CH:11][C:5]=2[S:4][CH2:3]1.COC(C1C=CC2SCC(=O)NC=2C=1)=O.[Li+].[OH-]>C1COCC1.O>[O:1]=[C:2]1[NH:7][C:6]2[CH:8]=[C:9]([CH:12]=[O:13])[CH:10]=[CH:11][C:5]=2[S:4][CH2:3]1

Participants

5

Reactant 3

HCID 3939Lithium HydroxideHCID 699501Methyl 3-oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylateHCID 7609933-oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylic acid

Product 1

HCID 109433483-Oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carbaldehydeYield 60%

Reagents, catalysts & solvents 1

HCID 21881883Oxolane--water (1/1)Solvent

Procedure

3-Oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxylic acid. To a solution of 3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxylic acid methyl ester (1.5 g, 6.7 mmol) in a THF/H2O mixture (1:1, 63 mL) was added 4 N LiOH (8.0 mL, 32 mmol) and the resulting solution was stirred at RT for 24 h. The solution was partially concentrated and diluted with H2O (50 mL). The solution was acidified using concentrated HCl and a solid precipitated. The solid was collected via filtration, washed with H2O and dried in vacuo to provide 0.79 g (60%) of the title compound as a white solid. MS (ESI): exact mass calculated for C9H7NO3S, 209.01; m/z found, 210.2 [M+H]+. 1H NMR (500 MHz, CD3OD): 7.65-7.61 (m, 2H), 7.40 (d, J=8.1, 1H), 3.48 (s, 2H).

Workup

  1. concentrationThe solution was partially concentrated
  2. additiondiluted with H2O (50 mL)
  3. customa solid precipitated
  4. filtrationThe solid was collected via filtration
  5. washwashed with H2O
  6. customdried in vacuo

Sources & evidence

ORD record
ord-69b9cbd35c2f4e9c9a5a79a658575c12
Source dataset
uspto-grants-2012_08
Patent number
US08242275B2

Reaction notes

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