Vanillic Acid → 2-(4-Hydroxy-3-methoxyphenyl)benzothiazole

HRID 2235902Notes

Reaction equation

HRID 2235902 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[SH:8].[OH:9][C:10]1[CH:18]=[CH:17][C:13]([C:14](O)=O)=[CH:12][C:11]=1[O:19][CH3:20].[OH-].[K+]>>[S:8]1[C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[N:1]=[C:14]1[C:13]1[CH:17]=[CH:18][C:10]([OH:9])=[C:11]([O:19][CH3:20])[CH:12]=1

Participants

4

Reactant 3

HCID 8468Vanillic AcidHCID 87132-AminothiophenolHCID 14797Potassium Hydroxide

Product 1

HCID 31552282-(4-Hydroxy-3-methoxyphenyl)benzothiazoleYield 3%

Procedure

A slurry of 2-aminothiophenol (357 mg, 2.85 mmol) in polyphosphoric acid (14.0 g) was heated to 110° C. and 4-hydroxy-3-methoxybenzoic acid (480 mg, 2.85 mmol) was added. After 2 h, the reaction mixture was cooled to rt. The mixture was poured carefully into ice cold water, and the solution was neutralized with KOH (3 M aqueous solution). The aqueous phase was extracted with EtOAc (2×). The combined organic layers were washed with Na2CO3 (1 M aqueous solution), HCl (1 M aqueous solution) and water, dried, and concentrated under reduced pressure. Purification by silica gel chromatography gave 22 mg (3%) of the title compound as an oil. 1H NMR (400 MHz, CDCl3): δ 8.02 (d, 1H), 7.88 (d, 1H), 7.72 (s, 1H), 7.55 (d, 1H), 7.48 (m, 1H), 7.36 (m, 1H), 7.00 (d, 1H), 5.92 (s, 1H), 4.03 (s, 3H).

Workup

  1. additionThe mixture was poured carefully into ice cold water
  2. extractionThe aqueous phase was extracted with EtOAc (2×)
  3. washThe combined organic layers were washed with Na2CO3 (1 M aqueous solution), HCl (1 M aqueous solution) and water
  4. customdried
  5. concentrationconcentrated under reduced pressure
  6. customPurification by silica gel chromatography

Sources & evidence

ORD record
ord-c5dbee5b14f74e3d9cb91d3e895bdb1a
Source dataset
uspto-grants-2010_05
Patent number
US07714004B2

Reaction notes

Loading…