Patent · US Expired

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

US4451378A · kind A · utility

4Cited by

2References

1Claims

0Family size

Assignee

BASF SE

Inventors

Hanspeter Hansen
Hans Rupert Merkle · Ludwigshafen, DE
Albrecht Mueller · Ludwigshafen, DE

Key dates

Filing date	Oct 14, 1982
Grant date	May 29, 1984
Priority date	—
Expiry date	Oct 14, 2002

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10S210/909
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

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.degree.-110.degree. 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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.