Methylthiourea → 2-Methylamino-5,6-dihydro-4H-benzothiazol-7-one

HRID 2102780Notes

Reaction equation

HRID 2102780 reaction equation
Br[CH:2]1[C:7](=[O:8])[CH2:6][CH2:5][CH2:4][C:3]1=O.[CH3:10][NH:11][C:12]([NH2:14])=[S:13]>N1C=CC=CC=1>[CH3:10][NH:11][C:12]1[S:13][C:2]2[C:7](=[O:8])[CH2:6][CH2:5][CH2:4][C:3]=2[N:14]=1

Participants

4

Reactant 2

HCID 2723704MethylthioureaHCID 27704762-Bromocyclohexane-1,3-dione

Product 1

HCID 34274902-Methylamino-5,6-dihydro-4H-benzothiazol-7-oneYield 43%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A solution of 2-bromo-cyclohexane-1,3-dione (8.0 g, 41.9 mmol) and methyl thiourea (3.77 g, 41.9 mmol) in pyridine (63 mL) was stirred at room temperature for 16 h. The reaction mixture was concentrated under vacuum, extracted with CH2Cl2 /10% aq NaCl solution, dried, filtered, and concentrated under vacuum. Crystallization from EtOAc afforded the title compound as yellow crystals (3.26 g, 43%): mp 180-182° C. Anal. RP-HPLC: tR 8.4 min (0-60% MeCN, purity 100%). 1H-NMR (CDCl3): δ 7.90 (s, 1H, NH), 2.99 (s, 3H, CH3), 2.72 (t, 2H, J 6.1, CH2), 2.49 (t, 2H, J 6.1, CH2), 2.10 (qu, 2H, J 6.1, CH2). 13C-NMR (CDCl3): δ 191.0, 176.6, 168.0, 120.0, 37.5, 32.5, 27.7, 23.2. MS: (ESI+) m/z 183.07 (M+H)+.

Workup

  1. concentrationThe reaction mixture was concentrated under vacuum
  2. extractionextracted with CH2Cl2 /10% aq NaCl solution
  3. customdried
  4. filtrationfiltered
  5. concentrationconcentrated under vacuum
  6. customCrystallization from EtOAc

Sources & evidence

ORD record
ord-3a878cd7311a4754a19f1aa0345b618a
Source dataset
uspto-grants-2009_08
Patent number
US07576091B2

Reaction notes

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