Ethanol → Prazosin

HRID 1580970Notes

Reaction equation

HRID 1580970 reaction equation
[CH3:1][O:2][C:3]1[C:10]([O:11][CH3:12])=[CH:9][C:6]([C:7]#[N:8])=[C:5]([NH2:13])[CH:4]=1.C(O)C.Cl.[O:18]1[CH:22]=[CH:21][CH:20]=[C:19]1[C:23]([N:25]1[CH2:30][CH2:29][N:28]([C:31](=N)OCC)[CH2:27][CH2:26]1)=[O:24].C([N:38](CC)CC)C>>[CH3:12][O:11][C:10]1[CH:9]=[C:6]2[C:5](=[CH:4][C:3]=1[O:2][CH3:1])[N:13]=[C:31]([N:28]1[CH2:29][CH2:30][N:25]([C:23]([C:19]3[O:18][CH:22]=[CH:21][CH:20]=3)=[O:24])[CH2:26][CH2:27]1)[N:8]=[C:7]2[NH2:38]

Participants

5

Reactant 4

HCID 702EthanolHCID 8471TriethylamineHCID 7359672-Amino-4,5-dimethoxybenzonitrileHCID 20506452Ethyl 4-(2-furoyl)piperazin-1-ylformimidate hydrochloride

Product 1

HCID 4893Prazosin

Procedure

To a stirred solution of 1.78 g. (0.01 mole) of 4,5-dimethoxy-2-aminobenzonitrile in 50 ml. of anhydrous ethanol is added 10 ml. of triethylamine, followed by 2.88 g. (0.01 mole) of ethyl 4-(2-furoyl)piperazin-1-ylformimidate hydrochloride. The reaction mixture is stirred at ambient temperature for 5 hours, and then it is heated under reflux for 12 hours. At this point, all the solvents are removed by evaporation in vacuo, and the residue is triturated under water. The solid is filtered off and dried, yielding crude 6,7-dimethoxy-4-amino-2-[4-(2-furoyl)piperazin-1-yl]quinazoline.

Workup

  1. temperatureit is heated
  2. temperatureunder reflux for 12 hours
  3. customAt this point, all the solvents are removed by evaporation in vacuo
  4. customthe residue is triturated under water
  5. filtrationThe solid is filtered off
  6. customdried

Sources & evidence

ORD record
ord-b46dba42025d44248377b8c45a1bea80
Source dataset
uspto-grants-1976_01
Patent number
US03935213

Reaction notes

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