Phosphorus oxychloride → 1-Chloro-7-nitro-3,4-dihydroisoquinoline

HRID 2211599Notes

Reaction equation

HRID 2211599 reaction equation
[CH2:1]1[C:7]2[CH:8]=[CH:9][C:10]([N+:12]([O-:14])=[O:13])=[CH:11][C:6]=2[C:4](=O)[NH:3][CH2:2]1.O=P(Cl)(Cl)[Cl:17]>>[Cl:17][C:4]1[C:6]2[C:7](=[CH:8][CH:9]=[C:10]([N+:12]([O-:14])=[O:13])[CH:11]=2)[CH2:1][CH2:2][N:3]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 131528427-Nitro-3,4-dihydroisoquinolin-1(2H)-one

Product 1

HCID 219596651-Chloro-7-nitro-3,4-dihydroisoquinoline

Procedure

Tricyclic heterocycles can be prepared by the process outlined in Scheme 35. 7-Nitro-2,3,4-trihydroisoquinolin-1-one 120 is heated in POCl3 at a temperature above RT, preferably at a temperature sufficient for reflux, to form the 1-chloro-7-nitro-3,4-dihydroisoquinoline 121. The 1-chloro-7-nitro-3,4-dihydroisoquinoline 121 is dissolved in a solvent, such as THF, and H2NNH2 is added. The reaction is heated with HC(OEt)3 at a temperature above RT, preferably at a temperature above about 75° C., and more preferably at a temperature at about 115° C. to give the nitro-substituted tricyclic. Hydrogenation, such as with an H2 atmosphere in the presence of a catalyst, such as Pd/C, gives 2-amino-5,6,7-trihydro-1,2,4-triazolo[3,4-a]isoquinoline 122.

Workup

  1. temperaturefor reflux

Sources & evidence

ORD record
ord-0ce0f44f3e9043219ecc0d5d0d95f470
Source dataset
uspto-grants-2006_09
Patent number
US07101868B2

Reaction notes

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