Calciumoxide → HCID 21269259, compound

HRID 1194269Notes

Reaction equation

HRID 1194269 reaction equation
[Cl:1][C:2]1[C:11]2[O:10][CH2:9][CH2:8][CH:7]([N:12]3[C:16]([C:17]([O:19][CH3:20])=[O:18])=[CH:15][N:14]=[CH:13]3)[C:6]=2[CH:5]=[C:4]([N+:21]([O-])=O)[CH:3]=1.[O-2].[Ca+2].[H][H]>[Pd].CO>[ClH:1].[NH2:21][C:4]1[CH:3]=[CH:2][C:11]2[O:10][CH2:9][CH2:8][CH:7]([N:12]3[C:16]([C:17]([O:19][CH3:20])=[O:18])=[CH:15][N:14]=[CH:13]3)[C:6]=2[CH:5]=1

Participants

6

Reactant 3

HCID 6850728CalciumoxideHCID 21269264HCID 21269264, compoundHCID 178418361HCID 178418361, compound

Product 1

HCID 21269259HCID 21269259, compoundYield 35.3%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

A mixture of 48 parts of methyl 1-(8-chloro-2,3-dihydro-6-nitro-4H-1-benzopyran-4-yl)-1H-imidazole-5-carboxylate, 8 parts of calcium oxide and 400 parts of methanol was hydrogenated at normal pressure and at room temperature with 2 parts of palladium-on-charcoal catalyst 5%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated. The residue was taken up in trichloromethane. The organic layer was washed with water and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (90:10 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was converted into the hydrochloride salt in a mixture of 2-propanol and 2,2'-oxybispropane. The salt was filtered off and salt overnight in vacuo at 80° C., yielding 18.3 parts (35.3%) of methyl 1-(6-amino-2,3-dihydro-4H-1-benzopyran-4-yl)-1H-imidazole-5-carboxylate monohydrochloride.2-propanolate (1:1 ); mp. 146.0° C. (compound 1.135).

Workup

  1. filtrationthe catalyst was filtered off
  2. customthe filtrate was evaporated
  3. washThe organic layer was washed with water
  4. customevaporated
  5. customThe residue was purified by column chromatography over silica gel using
  6. additiona mixture of trichloromethane and methanol (90:10 by volume) as eluent
  7. customThe pure fractions were collected
  8. customthe eluent was evaporated
  9. additionThe residue was converted into the hydrochloride salt in a mixture of 2-propanol and 2,2'-oxybispropane
  10. filtrationThe salt was filtered off

Sources & evidence

ORD record
ord-79e2512ae666423fa64a2e68d7daedcd
Source dataset
uspto-grants-1989_03
Patent number
US04813998

Reaction notes

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