Morpholine → 2-Methyl-6-morpholin-4-ylmethylene-5,6-dihydro-4H-benzothiazol-7-one

HRID 2102782Notes

Reaction equation

HRID 2102782 reaction equation
[CH3:1][C:2]1[S:3][C:4]2[C:10](=[O:11])[CH:9]([CH:12]=O)[CH2:8][CH2:7][C:5]=2[N:6]=1.[NH:14]1[CH2:19][CH2:18][O:17][CH2:16][CH2:15]1>C1(C)C=CC=CC=1>[CH3:1][C:2]1[S:3][C:4]2[C:10](=[O:11])[C:9](=[CH:12][N:14]3[CH2:19][CH2:18][O:17][CH2:16][CH2:15]3)[CH2:8][CH2:7][C:5]=2[N:6]=1

Participants

4

Reactant 2

HCID 8083MorpholineHCID 248876322-Methyl-7-oxo-4,5,6,7-tetrahydro-1,3-benzothiazole-6-carbaldehyde

Product 1

HCID 684158522-Methyl-6-morpholin-4-ylmethylene-5,6-dihydro-4H-benzothiazol-7-oneYield 89%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 2-methyl-7-oxo-4,5,6,7-tetrahydro-benzothiazole-6-carbaldehyde (2.0 g, 10.2 mmol) in dry toluene (8.1 mL), morpholine (1.0 mL, 1.0 g, 11.3 mmol) was added. The reaction mixture was heated under reflux for 2 h. On cooling a brown precipitate formed. The solvent was removed under vacuum and the brown solid residue was fractionated by flash column chromatography (20% EtOAc:hexane) to leave a yellow solid that was purified further by crystallisation from EtOH to afford the pure title product as yellow crystals (2.4 g, 87%): mp 186-187° C. Anal. RP-HPLC: tR 12.7 min (0-60% MeCN, purity 100%). 1H-NMR (CDCl3): δ 7.50 (s, 1H, CH), 3.80 (t, 4H, J 4.6), 3.55 (t, 4H, J 4.6), 3.00 (m, 4H, CH2—CH2), 2.80 (s, 3H, CH3). 13C-NMR (CDCl3): δ 182.0, 171.6, 162.3, 147.9, 133.2, 103.3, 67.0, 51.4, 26.7, 24.9, 20.2. MS (ESI+): m/z 287.05 (M+Na)+, 265.07 (M+H)+. Anal. (C13H16N2O2S)C, H, N.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 2 h
  3. temperatureOn cooling a brown precipitate
  4. customformed
  5. customThe solvent was removed under vacuum
  6. customto leave a yellow solid
  7. customthat was purified further by crystallisation from EtOH

Sources & evidence

ORD record
ord-df2a231c545f46079a867a84e2bf4bc6
Source dataset
uspto-grants-2009_08
Patent number
US07576091B2

Reaction notes

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