p-Toluenesulfonic acid → HCID 12219996, compound

HRID 2397858Notes

Reaction equation

HRID 2397858 reaction equation
[C:1]([CH2:6][C:7]([O:9]CC)=O)(=O)[CH2:2][CH2:3][CH3:4].[NH2:12][C:13]1[C:18]([OH:19])=[CH:17][CH:16]=[CH:15][N:14]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>COCCO>[OH:19][C:18]1[C:13]2=[N:12][C:1]([CH2:2][CH2:3][CH3:4])=[CH:6][C:7](=[O:9])[N:14]2[CH:15]=[CH:16][CH:17]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 281142-Amino-3-HydroxypyridineHCID 238498Ethyl 3-oxohexanoate

Product 1

HCID 12219996HCID 12219996, compoundYield 49.5%

Reagents, catalysts & solvents 1

HCID 80192-MethoxyethanolSolvent

Procedure

A mixture of 31.5 g of ethyl butyrylacetate, 11.0 g of 2-amino-3-pyridinol, 125 ml of ethyleneglycol monomethyl ether, and 1.0 g of p-toluenesulfonic acid is stirred and heated under reflux for 21 hours and then allowed to cool. The product that crystallizes is filtered and dried to give 10.1 g of 9-hydroxy-2-propyl-4H-pyrido[1,2-a]pyrimidin-4-one, m.p. 95°-96°. The filtrate is concentrated to one-half volume to give 5.8 g of solid, m.p. 92°-94°. This is extracted with two 50 ml portions of boiling diisopropyl ether to leave behind 1.0 g of an insoluble solid. From the diisopropyl ether extracts there is obtained 3.8 g of additional product, m.p. 95°-96°. The 1.0 g of solid insoluble in diisopropyl ether is recrystallized from acetonitrile to give 0.60 g of 9-hydroxy-2-propyl-4 H-pyrido[1,2-a]pyrimidin-4-one, salt with p-toluenesulfonic acid, m.p. 202° -204°. The same salt is prepared by mixing rapidly hot solutions of 1.40 g of the product, m.p. 95°-96° in 15 ml of acetonitrile and 1.30 g of p-toluenesulfonic acid in 15 ml of acetonitrile. A clear solution forms briefly and then the salt crystallizes. The yield of salt, m.p. 202°-204°, is 2.16 g.

Workup

  1. temperatureheated
  2. temperatureunder reflux for 21 hours
  3. temperatureto cool
  4. customThe product that crystallizes
  5. filtrationis filtered
  6. customdried

Sources & evidence

ORD record
ord-2b3323f07f4d476fae2d667f8add3e07
Source dataset
uspto-grants-1977_05
Patent number
US04022897

Reaction notes

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