2H-1,3,2-dioxaborino-[5,4-c]-1,2-benzo-thiazine 6,6-dioxides
US3966716A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 17, 1975 |
| Grant date | Jun 29, 1976 |
| Priority date | — |
| Expiry date | Mar 17, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F5/022
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Process for the production of substituted pyrano[3,2-c] [1,2]benzothiazine 6,6-dioxides and novel intermediates produced thereby of the general formula I: ##SPC1## wherein R represents hydrogen and lower alkyl; R' represents lower alkyl and formyl; by reacting, as the first step, the corresponding 2-substituted-2H-1,2-benzothiazin-4(3H)-one 1,1-dioxide (II) with a boron trifluoride compound and an acid anhydride IV; alternately, the starting material may be a 3-acetyl-2-substituted-2H-1,2-benzothiazin-4-[3H]-one 1,1-dioxide (III) which is reacted with the boron trifluoride compound, without the necessity for the acid anhydride (IV). Starting materials II and III subjected to step one of the process yield novel boron complex intermediates V (2,2-difluoro-4,5-disubstituted-2H-1,3,2-dioxaborino[5,4-c]-1,2-benzothiaz ine 6,6-dioxide). Boron complex intermediate V, in the second step of the process, is subjected to treatment with a Vilsmeier reagent (phosphorus oxychloride together with dimethylformamide), followed by hydrolysis. The substituted-pyrano[3,2-c][1,2]benzothiazine 6,6-dioxides of formula I prepared by the process of this invention have anti-secretory activity and are useful…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.