Hydrochloric Acid → 6-benzyl-3-methyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione

HRID 742960Notes

Reaction equation

HRID 742960 reaction equation
[OH:1]O.[CH2:3]([N:10]1[CH2:22][CH2:21][C:13]2[NH:14][C:15](=S)[N:16]([CH3:19])[C:17](=[O:18])[C:12]=2[CH2:11]1)[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.[OH-].[Na+].Cl>O>[CH2:3]([N:10]1[CH2:22][CH2:21][C:13]2[NH:14][C:15](=[O:1])[N:16]([CH3:19])[C:17](=[O:18])[C:12]=2[CH2:11]1)[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 784Hydrogen PeroxideHCID 14798Sodium HydroxideHCID 103793236-benzyl-3-methyl-2-thioxo-2,3,5,6,7,8-hexahydropyrido[4,3-d]pyrimidin-4(1H)-one

Product 1

HCID 100160286-benzyl-3-methyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

3.2 1 of 30% hydrogen peroxide were added dropwise at 0° C. over a period of 51/2 h, with stirring, to a suspension of 210 g of 6-benzyl-3-methyl-2-thioxo-2,3,5,6,7,8-hexahydro-1H-pyrido[4,3-d]pyrimidin-4-one from b) in a solution of 78 g of NaOH in 4 1 of water. After subsequent stirring for 1/2 hour at 0° C., the pH of 9.7 was adjusted to 7.4 with conc. hydrochloric acid and the precipitate was filtered off, washed with water and dried. The above preparation was repeated and the precipitates were combined (396 g). These were purified by suspension in I 1 of water and dissolution with 33% sodium hydroxide solution (pH 13.5). Activated charcoal was added, with stirring, the mixture was filtered and the filtrate was adjusted to pH 10. The precipitate formed was filtered off with suction, washed with water and dried under reduced pressure to give 192 g of 6-benzyl-3-methyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione, which was debenzylated by hydrogenolysis in d).

Workup

  1. filtrationthe precipitate was filtered off
  2. washwashed with water
  3. customdried
  4. customThe above preparation
  5. customThese were purified by suspension in I 1 of water and dissolution with 33% sodium hydroxide solution (pH 13.5)
  6. additionActivated charcoal was added
  7. stirringwith stirring
  8. filtrationthe mixture was filtered
  9. customThe precipitate formed
  10. filtrationwas filtered off with suction
  11. washwashed with water
  12. customdried under reduced pressure

Sources & evidence

ORD record
ord-1b23f7f87a9547d7a96431a21fadb662
Source dataset
uspto-grants-1996_09
Patent number
US05556854

Reaction notes

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