2-Chloro-6,7-dimethoxy-4-quinazolinamine → Doxazosin

HRID 428378

Reaction equation

[NH2:1][C:2]1[C:11]2[C:6](=[CH:7][C:8]([O:14][CH3:15])=[C:9]([O:12][CH3:13])[CH:10]=2)[N:5]=[C:4](Cl)[N:3]=1.[O:17]1[C:22]2[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=2[O:20][CH2:19][CH:18]1[C:27]([N:29]1[CH2:34][CH2:33][NH:32][CH2:31][CH2:30]1)=[O:28]>C(O)CCC>[CH3:13][O:12][C:9]1[CH:10]=[C:11]2[C:2]([NH2:1])=[N:3][C:4]([N:32]3[CH2:33][CH2:34][N:29]([C:27]([CH:18]4[O:17][C:22]5[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=5[O:20][CH2:19]4)=[O:28])[CH2:30][CH2:31]3)=[N:5][C:6]2=[CH:7][C:8]=1[O:14][CH3:15]

Participants

Conditions

Temperature: 75 °C

Procedure

4-amino-2-chloro-6,7-dimethoxyquinazoline (3.2 g, 13.35 mmol) and compound 1 (3.4 g, 13.75 mmol) prepared from Example 3 were dissolved in 72 mL of n-butanol. The mixture was refluxed under nitrogen for 3.5 hours. After cooling to 75° C., the solid product was obtained by filtration and dried to afford 5.25 g of hydrochloride salt of Doxazosin (10.76 mmol, 81% yield). 1 N NaOH solution was added to the salt. The mixture was heated to help the salt dissolved. After cooling, the mixture was extracted with 150 mL of dichloromethane twice. The organic layer was dried with anhydrous sodium sulfate and concentrated to afford 4.61 g of Doxazosin.

Workup

temperatureThe mixture was refluxed under nitrogen for 3.5 hours
customthe solid product was obtained by filtration
customdried

Sources & evidence

ORD record: ord-c0da6d462a2a4f0eb506784a32c61fdd
Source dataset: uspto-grants-2001_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06313294B1

Linked notes

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