Method for preparation of 2-alkyl-1,2-benzisothiazolin-3-ones
View Patent ↗A method for preparation of 2-alkyl-1,2-benzisothiazolin-3-ones from 1,2-benzisothiazolin-3-one by contacting 1,2-benzisothiazolm-3-one with a dialkyl carbonate in the presence of a base.
1. A method for preparation of 2-alkyl-1,2-benzisothiazolin-3-ones from 1,2-benzisothiazolin-3-one; said method comprising contacting 1,2-benzisothiazolin-3-one with a dialkyl carbonate and a base.
2. The method of claim 1 in which the dialkyl carbonate has primary alkyl groups.
3. The method of claim 2 in which the base is an alkali metal carbonate, alkali metal hydroxide, alkali metal alkoxycarbonate, alkali metal alkoxide or magnesium methoxide.
4. The method of claim 3 in which the dialkyl carbonate has primary C 1 -C 4 alkyl groups.
5. The method of claim 4 in which the peak reaction temperature is from 140° C. to 180° C.
6. The method of claim 5 in which a ratio of moles of the base to moles of 1,2-benzisothiazolin-3-one is from 0.02/1 to 0.5/1.
7. The method of claim 6 in which a weight ratio of dialkyl carbonate to 1,2-benzisothiazolin-3-one is from 3/1 to 15/1.
8. The method of claim 7 in which the dialkyl carbonate is dimethyl carbonate.
9. The method of claim 8 in which the base is sodium or potassium carbonate.
10. The method of claim 9 in which the peak reaction temperature is from 145° C. to 170° C.