Dimethylformamide → Prazosin

HRID 1580969Notes

Reaction equation

HRID 1580969 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[N:15](C)C=O.Cl.[O:20]1[CH:24]=[CH:23][CH:22]=[C:21]1[C:25]([N:27]1[CH2:32][CH2:31][N:30]([C:33](=N)OCC)[CH2:29][CH2:28]1)=[O:26].[H-].[Na+]>O>[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:33]([N:30]1[CH2:31][CH2:32][N:27]([C:25]([C:21]3[O:20][CH:24]=[CH:23][CH:22]=3)=[O:26])[CH2:28][CH2:29]1)[N:8]=[C:7]2[NH2:15]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 24758Sodium hydrideHCID 7359672-Amino-4,5-dimethoxybenzonitrileHCID 20506452Ethyl 4-(2-furoyl)piperazin-1-ylformimidate hydrochloride

Product 1

HCID 4893Prazosin

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a stirred solution of 1.78 g. (0.01 mole) of 4,5-dimethoxy-2-aminobenzonitrile in 30 ml. of N,N-dimethylformamide is added 2.88 g. (0.01 mole) of ethyl 4-(2-furoyl)piperazin-1-ylformimidate hydrochloride, followed by 855 mg. (0.02 mole) of a 56.1% dispersion of sodium hydride in mineral oil. The reaction mixture is stirred at ambient temperature for 30 minutes, and then it is heated to ca. 100° C. and maintained at that temperature for 12 hours. The reaction mixture is cooled to ambient temperature, diluted with an excess of water, and then extracted with chloroform. The chloroform extract is washed several times with water, dried using anhydrous magnesium sulfate, and then evaporated to dryness in vacuo. This affords crude 6,7-dimethoxy-4-amino-2-[4-(2-furoyl)piperazin-1-yl]quinazoline, which is purified further by recrystallization from aqueous ethanol.

Workup

  1. temperatureit is heated to ca. 100° C.
  2. temperaturemaintained at that temperature for 12 hours
  3. temperatureThe reaction mixture is cooled to ambient temperature
  4. extractionextracted with chloroform
  5. extractionThe chloroform extract
  6. washis washed several times with water
  7. customdried
  8. customevaporated to dryness in vacuo

Sources & evidence

ORD record
ord-38414b642f5841ef8bb8bfa76bc39ada
Source dataset
uspto-grants-1976_01
Patent number
US03935213

Reaction notes

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