Potassium thiocyanate → Methyl 2-amino-4-methoxybenzo[d]thiazole-6-carboxylate

HRID 1177349Notes

Reaction equation

HRID 1177349 reaction equation
[NH2:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1[O:12][CH3:13].[C:14]([S-:16])#[N:15].[K+]>CO.[O-]S([O-])(=O)=O.[Cu+2]>[NH2:15][C:14]1[S:16][C:11]2[CH:10]=[C:5]([C:6]([O:8][CH3:9])=[O:7])[CH:4]=[C:3]([O:12][CH3:13])[C:2]=2[N:1]=1

Participants

5

Reactant 2

HCID 516872Potassium thiocyanateHCID 602411Methyl 4-amino-3-methoxybenzoate

Product 1

HCID 59560269Methyl 2-amino-4-methoxybenzo[d]thiazole-6-carboxylateYield 84%

Reagents, catalysts & solvents 2

HCID 24462Copper SulfateCatalystHCID 887MethanolSolvent

Procedure

To a solution of methyl 4-amino-3-methoxybenzoate (307 g, 1.696 mol) in anhydrous methanol (4 L) was added an intimated mixture of KSCN (1640 g, 16.9 mol) and anhydrous CuSO4 (1350 g, 8.44 mol) in one portion. The mixture was heated to reflux for 4 h. TLC (EtOAc/Petroleum ether 1:4) showed the reaction was complete. The mixture was filtered and the filtrate was diluted with water. The solution was heated to boiling until a slightly clear solution formed. The mixture was cooled to ambient temperature and left standing for 1 day. A dark yellow solid was formed, which was collected by filtration to afford the desired product (338 g, 84%) as a dark yellow solid. 1H NMR (400 MHz, CDCl3): δ 9.000-8.200 (br, 2H), 8.052 (s, 1H), 7.435 (s, 1H), 3.927 (s, 3H), 3.827 (s, 3H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 4 h
  3. filtrationThe mixture was filtered
  4. additionthe filtrate was diluted with water
  5. temperatureThe solution was heated
  6. customformed
  7. waitleft
  8. customA dark yellow solid was formed
  9. filtrationwhich was collected by filtration

Sources & evidence

ORD record
ord-62dbd3c4ccf24a029e1a0128ada9c01e
Source dataset
uspto-grants-2010_11
Patent number
US07842713B2

Reaction notes

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