P-Anisidine → 7-Methoxy-2H-benzo[e][1,2,4]thiadiazin-3(4H)-one 1,1-dioxide

HRID 730483Notes

Reaction equation

Cl[S:2]([N:5]=[C:6]=[O:7])(=[O:4])=[O:3].[CH3:8][O:9][C:10]1[CH:16]=[CH:15][C:13]([NH2:14])=[CH:12][CH:11]=1.[Cl-].[Al+3].[Cl-].[Cl-]>[N+](CC)([O-])=O>[CH3:8][O:9][C:10]1[CH:16]=[CH:15][C:13]2[NH:14][C:6](=[O:7])[NH:5][S:2](=[O:4])(=[O:3])[C:12]=2[CH:11]=1

Participants

Conditions

Temperature: -40 °C

Procedure

Chlorosulfonyl isocyanate (17 mL, 195 mmol) was dissolved in nitroethane (150 mL) and cooled to −40° C. A solution of 4-methoxyaniline (20 g, 162 mmol) in nitroethane (100 mL) was then added dropwise with stirring. After the addition was completed, the reaction was stirred for an additional 5 min and aluminum chloride (25 g, 195 mmol) was added. The mixture was then quickly heated to 110° C. with stirring for 20 min. The crude material was then poured onto ice and the precipitate was collected by vacuum filtration, washed with cold water, and dried in vacuo to afford the desired product, 7-methoxy-1,1-dioxo-1,4-dihydro-2H-1λ6-benzo[1,2,4]thiadiazin-3-one (35 g, 153.5 mmol, 79% yield) as a purple powder. 1H NMR (400 MHz, DMSO-d6): δ 3.6 (br, 1H), 3.78 (s, 3H), 7.2 (m, 3H), 11.05 (s, 1H).

Workup

additionAfter the addition
stirringthe reaction was stirred for an additional 5 min
temperatureThe mixture was then quickly heated to 110° C.
stirringwith stirring for 20 min
filtrationthe precipitate was collected by vacuum filtration
washwashed with cold water
customdried in vacuo

Sources & evidence

ORD record: ord-67301235b5fe4983b5de37eca379d1e3
Source dataset: uspto-grants-2009_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07582754B2

Reaction notes

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