Citric Acid → 3-(1,1-dioxido-4H-1,2,4-benzothiadiazin-3-yl)-4-hydroxy-1,1-dipropyl-2(1H)-naphthalenone

HRID 494441Notes

Reaction equation

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

Participants

Conditions

Temperature: 130 °C

Procedure

A suspension of the product of Example 1G (150 mg, 0.34 mmol) in 10% potassium hydroxide solution (9 mL) was stirred at 130° C. for 30 hours, cooled to 25° C., acidified to pH 3 by addition of 1 M citric acid, stirred with ethyl acetate, and filtered through Celite®. The organic layer from the filtrate was washed with saturated sodium chloride solution, dried (Na2SO4), filtered and concentrated in vacuo. The residue was recrystallized from ether-hexane solution to afford the title compound (83 mg, 57%). 1H NMR (300 MHz, CDCl3): δ16.70 (s, 1 H), 14.22 (s, 1 H), 8.26 (d, J=8.09 Hz, 1 H), 7.99 (d, J=8.09 Hz, 1 H), 7.67 (m, 1H), 7.47 (m, 3 H), 7.29 (m, 2 H), 2.25 (m, 2 H), 1.86 (m, 2 H), 0.89 (m, 2 H), 0.70 (m, 8 H).

Workup

temperaturecooled to 25° C.
filtrationfiltered through Celite®
washThe organic layer from the filtrate was washed with saturated sodium chloride solution
dry with materialdried (Na2SO4)
filtrationfiltered
concentrationconcentrated in vacuo
customThe residue was recrystallized from ether-hexane solution

Sources & evidence

ORD record: ord-4372c992d82d47bca9ed556d6c7642ec
Source dataset: uspto-grants-2009_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07538105B2

Reaction notes

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