Hydrochloric Acid → 6-Isothiocyanato-2-naphthoic acid

HRID 385184Notes

Reaction equation

HRID 385184 reaction equation
[C:1](=[S:3])=S.[NH2:4][C:5]1[CH:6]=[C:7]2[C:12](=[CH:13][CH:14]=1)[CH:11]=[C:10]([C:15]([OH:17])=[O:16])[CH:9]=[CH:8]2.C(N(CC)CC)C.II.Cl.S([O-])([O-])=O.[Na+].[Na+]>O1CCCC1.O>[N:4]([C:5]1[CH:6]=[C:7]2[C:12](=[CH:13][CH:14]=1)[CH:11]=[C:10]([C:15]([OH:17])=[O:16])[CH:9]=[CH:8]2)=[C:1]=[S:3]

Participants

9

Reactant 6

HCID 313Hydrochloric AcidHCID 807IodineHCID 6348Carbon DisulfideHCID 8471TriethylamineHCID 24437Sodium SulfiteHCID 27339546-Aminonaphthalene-2-carboxylic acid

Product 1

HCID 442063076-Isothiocyanato-2-naphthoic acidYield 96%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

Carbon disulfide (0.26 mL, 4.4 mmol) was added to a mixture comprising 6-amino-2-naphthoic acid (0.28 g, 1.5 mmol), tetrahydrofuran (1.0 mL), water (1.0 mL) and triethylamine (0.51 mL, 3.6 mmol), followed by stirring at room temperature for 24 hours. To the obtained reaction mixture, a tetrahydrofuran (1.0 mL) solution of iodine (0.41 g, 1.6 mmol) was dropwise added over a period of 5 minutes at 0° C., followed by stirring at 0° C. for further two hours. Thereafter, 1M hydrochloric acid (1.5 mL) and sodium sulfite (38 mg, 0.30 mmol) were added and mixed. The formed insoluble matter was collected by filtration and dried under reduced pressure. Then, carbon disulfide (2.0 mL) was added and thoroughly mixed. Then, the insoluble matter was collected by filtration to obtain 6-isothiocyanato-2-naphthoic acid as a cream-colored solid (0.32 g, yield: 96%, HPLC purity: 94%, HPLC retention time: 3.7 min). LC-MS ES-228 (retention time: 4.5 min, condition 1).

Workup

  1. customTo the obtained reaction mixture
  2. stirringby stirring at 0° C. for further two hours
  3. additionmixed
  4. filtrationThe formed insoluble matter was collected by filtration
  5. customdried under reduced pressure
  6. additionThen, carbon disulfide (2.0 mL) was added
  7. additionthoroughly mixed
  8. filtrationThen, the insoluble matter was collected by filtration

Sources & evidence

ORD record
ord-a038fecf622f415a83ff06823fce4221
Source dataset
uspto-grants-2013_02
Patent number
US08367857B2

Reaction notes

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