Sodium Hydroxide → Doxazosin

HRID 428360

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[C:7]2[C:9]([NH2:31])=[N:10][C:11]([N:13]3[CH2:18][CH2:17][N:16]([C:19]([CH:21]4[O:30][C:29]5[C:24](=[CH:25][CH:26]=[CH:27][CH:28]=5)[O:23][CH2:22]4)=[O:20])[CH2:15][CH2:14]3)=[N:12][C:6]2=[CH:5][C:4]=1[O:32][CH3:33].Cl.[OH-].[Na+]>>[CH3:1][O:2][C:3]1[CH:8]=[C:7]2[C:9]([NH2:31])=[N:10][C:11]([N:13]3[CH2:14][CH2:15][N:16]([C:19]([CH:21]4[O:30][C:29]5[CH:28]=[CH:27][CH:26]=[CH:25][C:24]=5[O:23][CH2:22]4)=[O:20])[CH2:17][CH2:18]3)=[N:12][C:6]2=[CH:5][C:4]=1[O:32][CH3:33]

Participants

Reactant 2

HCID 14798Sodium Hydroxide

HCID 11591230Doxazosin Monohydrochloride

Product 1

HCID 3157Doxazosin

Procedure

4-Amino-2-chloro-6,7-bismethoxyquinazoline (III) (3.2 grams, 13.35 mmole), Compound 4 from Example 2 (3.4 grains, 13.75 mmole) and n-butanol (72 ml) were subjected to a 50 ml round-bottom flask and heated under refluxing for 3.5 hours under a nitrogen atmosphere. Cooling to 75° C., the solid products were filtered and collected, dried in an oven to obtain 5.25 grams of Doxazosin hydrochloride (10.76 mmole, Yield: 81%). The Doxazosin hydrochloride was added to a 1N NaOH solution and heated for dissolution. After cooling, the solution was extracted with 150 ml of dichloromethane twice. The organic layer was filtered and dried with anhydrous sulfate, and concentrated to obtain 4.61 grams of white Doxazosin solid: 1H NMR (CDCl3) δ 3.63-4.09 (m, 8 H), 3.91 (s, 3H), 3.96 (s, 3H), 4.35 (dd, J=11.9, 7.9 Hz, 1H), 4.52 (dd, J=11.9, 2.4 Hz, 1H), 4.88 (dd, J=7.9, 2.4 Hz, 1H), 6.85-6.95 (m, 5H)

Workup

temperatureheated for dissolution
temperatureAfter cooling
extractionthe solution was extracted with 150 ml of dichloromethane twice
filtrationThe organic layer was filtered
dry with materialdried with anhydrous sulfate
concentrationconcentrated

Sources & evidence

ORD record: ord-69da2c6d5cec485f9abdf4cf929fe71a
Source dataset: uspto-grants-2001_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06313293B1

Linked notes

Loading…