Thiophene → ethyl 6-amino-3,4-dihydro-2H-1-benzopyran-2-carboxylate

HRID 1906892Notes

Reaction equation

HRID 1906892 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][CH:11]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH2:10][CH2:9][C:8]=2[CH:18]=1)([O-])=O.S1C=CC=C1.[H][H]>CO.[Pd]>[NH2:1][C:4]1[CH:5]=[CH:6][C:7]2[O:12][CH:11]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH2:10][CH2:9][C:8]=2[CH:18]=1

Participants

6

Reactant 3

HCID 8030ThiopheneHCID 20211055ethyl 3,4-dihydro-6-nitro-2H-1-benzopyran-2-carboxylateHCID 178418361HCID 178418361, compound

Product 1

HCID 20211057ethyl 6-amino-3,4-dihydro-2H-1-benzopyran-2-carboxylateYield 90%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent2×

Procedure

A mixture of 59.8 parts of ethyl 3,4-dihydro-6-nitro-2H-1-benzopyran-2-carboxylate, 3 parts of a solution of thiophene in methanol 1% and 480 parts of methanol was hydrogenated at normal pressure and at room temperature with 5 parts of palladium-on-charcoal catalyst 10%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated, yielding 48 parts (90%) of ethyl 6-amino-3,4-dihydro-2H-1-benzopyran-2-carboxylate as a residue (intermediate 24).

Workup

  1. filtrationthe catalyst was filtered off
  2. customthe filtrate was evaporated

Sources & evidence

ORD record
ord-467db83293764d3185b6aa9106685d10
Source dataset
uspto-grants-1987_03
Patent number
US04654362

Reaction notes

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