O-Phenylenediamine → 3-(1H-Benzoimidazol-2-yl)-1H-[1,8]naphthyridin-2-one

HRID 1017709Notes

Reaction equation

HRID 1017709 reaction equation
C(O[C:4]([C:6]1[C:7](=[O:16])[NH:8][C:9]2[C:14]([CH:15]=1)=[CH:13][CH:12]=[CH:11][N:10]=2)=O)C.[C:17]1([NH2:24])[CH:22]=[CH:21][CH:20]=[CH:19][C:18]=1[NH2:23].C(=O)(O)[O-].[Na+]>>[NH:23]1[C:18]2[CH:19]=[CH:20][CH:21]=[CH:22][C:17]=2[N:24]=[C:4]1[C:6]1[C:7](=[O:16])[NH:8][C:9]2[C:14]([CH:15]=1)=[CH:13][CH:12]=[CH:11][N:10]=2

Participants

4

Reactant 3

HCID 7243O-PhenylenediamineHCID 516892Sodium BicarbonateHCID 11564777Ethyl 2-hydroxy-1,8-naphthyridine-3-carboxylate

Product 1

HCID 1358341333-(1H-Benzoimidazol-2-yl)-1H-[1,8]naphthyridin-2-one

Conditions

Temperature
200 °C

Procedure

A mixture of 5-3 (300 mg, 1.37 mmol, 1 equiv) and 1,2-phenylenediamine (223 mg, 2.06 mmol, 1.5 equiv) in polyphosphoric acid (8 mL) was heated at 200° C. for 16 h. The hot rxn mixture was poured into ice water (50 mL), and the resulting mixture was allowed to stand until all polyphosphoric acid had dissolved. The acidic suspension was neutralized with saturated aqueous sodium bicarbonate solution, then extracted with ethyl acetate (5×100 mL). The combined organic layers were dried over sodium sulfate and concentrated. The residue was suspended in ethyl acetate (50 mL) aided by sonication, and the solids were filtered to give 3-(1H-benzoimidazol-2-yl)-1H-[1,8]naphthyridin-2-one (5-4) as a yellow solid.

Workup

  1. dissolutionhad dissolved
  2. extractionextracted with ethyl acetate (5×100 mL)
  3. dry with materialThe combined organic layers were dried over sodium sulfate
  4. concentrationconcentrated
  5. customaided by sonication
  6. filtrationthe solids were filtered

Sources & evidence

ORD record
ord-e4e7748d7ef6412dbcf26cafccf4d749
Source dataset
uspto-grants-2002_11
Patent number
US06479512B1

Reaction notes

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