Dimethyl Sulfate → methyl 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide

HRID 1657398Notes

Reaction equation

[OH-].[Na+].[OH:3][C:4]1[C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][C:8]=2[S:7](=[O:15])(=[O:14])[NH:6][C:5]=1[C:16]([O:18][CH3:19])=[O:17].S(OC)(O[CH3:24])(=O)=O>CN(C=O)C.O>[OH:3][C:4]1[C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][C:8]=2[S:7](=[O:14])(=[O:15])[N:6]([CH3:24])[C:5]=1[C:16]([O:18][CH3:19])=[O:17]

Participants

Conditions

Temperature: 30 °C

Procedure

To a suspension of 3.5 grams (0.086 moles) of sodium hydroxide in 68 ml DMF, a solution of 20 grams (.078 moles) of methyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide is added in 34 ml DMF over a period of about 5 minutes at about 25°C. 11.9 Grams (0.094 moles) of dimethyl sulphate is added over a period of about 30 minutes at a maximum temperature of 30°C. The reaction is stirred for 3 hours at 30°C. and diluted with about 150 ml of water. It is cooled to 15°C., filtered and washed well with water. After drying, there is obtained 20 grams (95%) of product, m.p. 163°-165°C.

Workup

temperatureIt is cooled to 15°C.
filtrationfiltered
washwashed well with water
customAfter drying

Sources & evidence

ORD record: ord-f8bfb467c53c4f0cbf85860c9033879d
Source dataset: uspto-grants-1976_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US03960856

Reaction notes

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