Water → 5-Methyl-2-oxo-1,2-dihydro-1,6-naphthyridine-3-carboxylic acid

HRID 462716Notes

Reaction equation

HRID 462716 reaction equation
[CH3:1][C:2]1[N:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH:4]=[C:5]([C:13]#N)[C:6](=[O:12])[NH:7]2.S(=O)(=O)(O)O.[OH2:20].[OH-:21].[NH4+]>CCOCC.C(O)(=O)C.CO>[CH3:1][C:2]1[N:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH:4]=[C:5]([C:13]([OH:21])=[O:20])[C:6](=[O:12])[NH:7]2

Participants

8

Reactant 4

HCID 962WaterHCID 1118Sulfuric AcidHCID 14923Ammonium HydroxideHCID 57130685-methyl-2-oxo-1H-1,6-naphthyridine-3-carbonitrile

Product 1

HCID 132320525-Methyl-2-oxo-1,2-dihydro-1,6-naphthyridine-3-carboxylic acid

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 887MethanolSolventHCID 3283Diethyl EtherSolvent

Procedure

E-6. 1,2-Dihydro-5-methyl-2-oxo-1,6-naphthyridine-3-carboxylic acid--A mixture containing 63 g of 1,2-dihydro-5-methyl-2-oxo-1,6-naphthyridine-3-carbonitrile, 100 ml of concentrated sulphuric acid and 100 ml of water was heated on a steam bath for 16 hours, after which time tlc analyses (20% methanol in ether) indicated the presence of a considerable amount of starting material. Therefore, the reaction mixture was heated in a oil bath at 135°-140° C. for 8 hours, cooled to room temperature and poured on ice (1 l. beaker, 1/3 filled). The resulting aqueous mixture was neutralized by adding aqueous ammonium hydroxide until slightly basic and was then reacidified by adding acetic acid. The resulting solid was collected, washed successively with water and methanol, and dried at 100° C. to yield 54.8 g of 1,2-dihydro-5-methyl-2-oxo-1,6-naphthyridine-3-carboxylic acid, m.p. 255°-257° C. with decomposition. Another 7.2 g of the product, m.p. 252° -255° C. was obtained from the mother liquor.

Workup

  1. temperaturewas heated on a steam bath for 16 hours
  2. temperatureTherefore, the reaction mixture was heated in a oil bath at 135°-140° C. for 8 hours
  3. additionpoured on ice (1 l. beaker, 1/3 filled)
  4. customThe resulting solid was collected
  5. washwashed successively with water and methanol
  6. customdried at 100° C.

Sources & evidence

ORD record
ord-5846d8dde2564718af43c6ebd0fc4564
Source dataset
uspto-grants-1985_05
Patent number
US04517190

Reaction notes

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