2-Hydroxy-1-naphthaldehyde → 2-(5-carboxy-2-benzoxazolyl)-3H-naphtho[2,1-b]pyran-3-one

HRID 329705

Reaction equation

HRID 329705 reaction equation
[OH:1][C:2]1[CH:11]=[CH:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]=1[CH:12]=O.C([O:16][C:17]([CH2:19][C:20]1[O:21][C:22]2[CH:28]=[CH:27][C:26]([C:29]([OH:31])=[O:30])=[CH:25][C:23]=2[N:24]=1)=O)C>N1CCCCC1.C(O)(=O)C.C(O)C>[C:29]([C:26]1[CH:27]=[CH:28][C:22]2[O:21][C:20]([C:19]3[C:17](=[O:16])[O:1][C:2]4[CH:11]=[CH:10][C:9]5[C:4]([C:3]=4[CH:12]=3)=[CH:5][CH:6]=[CH:7][CH:8]=5)=[N:24][C:23]=2[CH:25]=1)([OH:31])=[O:30]

Participants

6

Reactant 2

HCID 128192-Hydroxy-1-naphthaldehydeHCID 198714242-Ethoxycarbonylmethyl-5-carboxybenzoxazole

Product 1

HCID 198714232-(5-carboxy-2-benzoxazolyl)-3H-naphtho[2,1-b]pyran-3-oneYield 56%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidCatalystHCID 8082PiperidineCatalystHCID 702EthanolSolvent

Procedure

A mixture of 2-hydroxy-1-naphthaldehyde (1.72 g, 0.01 mol), 2-ethoxycarbonylmethyl-5-carboxybenzoxazole (2.49 g, 0.01 mol), ethanol (30 mL), piperidine (10 drops), and acetic acid (5 drops) is heated at reflux for 3 hours. After cooling the reaction mixture is filtered to isolate the yellow fluorescent product which is then washed with ethanol and dried in air to yield 2.0 g (56% of theory) of 2-(5-carboxy-2-benzoxazolyl)-3H-naphtho[2,1-b]pyran-3-one having the structure ##STR19##

Workup

  1. temperatureis heated
  2. temperatureat reflux for 3 hours
  3. temperatureAfter cooling the reaction mixture
  4. filtrationis filtered
  5. customto isolate the yellow fluorescent product which
  6. washis then washed with ethanol
  7. customdried in air

Sources & evidence

ORD record
ord-f256b0f0768d4dde922bb36ecab302f2
Source dataset
uspto-grants-1990_01
Patent number
US04892923

Linked notes

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