Patent · US Expired

Synthesis of indoles by dehydrogenation of indolines

US5536843A · kind A · utility

3Cited by

0References

18Claims

0Family size

Assignee

Henkel Kommanditgesellschaft auf Aktien · DE

Inventors

Georg Knuebel · Goldkronach, DE
Roswitha Michel · Goldkronach, DE
David Rose · Hilden, DE

Key dates

Filing date	Aug 25, 1994
Grant date	Jul 16, 1996
Priority date	—
Expiry date	Aug 25, 2014

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D209/30
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

##STR1## By dehydrating indolines or their salts, the corresponding indoles having formula (I) are obtained. In the formula, R.sup.1 and R.sup.3 represent independently from each other hydrogen or alkyl groups with 1 to 4 C atoms, R.sup.2 stands for hydrogen, a methyl or a carboxyl group, R.sup.4 and R.sup.5 represent independently from each other hydrogen, amino groups, hydroxy groups, alkyl groups with 1 to 4 C atoms or alkoxy groups with 1 to 4 C atoms, or, in case R.sup.4 and R.sup.5 are bound to adjacent C atoms, both residues may also represent together an alkylene dioxy group with 1 to 4 C atoms. This process allows high yields of very pure indoles to be produced.

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