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U.S. Department of Energy
Office of Scientific and Technical Information

Isolation of 3-isopropyl-2,1,3-benzothiadiazin-4-one-2,2-dioxide from waste water from its preparation

Patent ·
OSTI ID:6508626

3-Isopropyl-2,1,3-benzothiadiazin-4-one-2,2-dioxide (bentazone) is isolated from waste water, originating from its preparation and working up, by treating the waste water with an acid to bring the pH initially to 7.5-9.5, adding 0.2-0.5% by volume, based on the waste water, of a 40-60 percent strength by weight aqueous bentazone salt solution and heating the mixture for 15-30 minutes at 75/sup 0/-110/sup 0/ C. The solution thus treated is then cooled and brought to pH 1-3 with a mineral acid, whereupon the bentazone precipitates in a form which can be filtered off.

Assignee:
BASF Aktiengesellschaft (Germany, Federal Republic of)
Patent Number(s):
US 4451378
OSTI ID:
6508626
Country of Publication:
United States
Language:
English