Process for the manufacture of benzoxazole, benzthiazole and benzimidazole derivatives
US4064136A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1976 |
| Grant date | Dec 20, 1977 |
| Priority date | — |
| Expiry date | Jul 13, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B29/32
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Process for the manufacture of a heterocyclic compound of the formula I ##STR1## in which Y denotes a --CN, --COOR' or ##STR2## group, in which R' can be an optionally substituted alkyl or aryl radical and R" and R"' independently of one another can have the same meaning as R' or can be hydrogen or, conjointly with the nitrogen atom, can form a heterocyclic 5-membered or 6-membered ring and X denotes a --S-- or --O-- atom or a --NR"-- group and the ring A can carry non-ionic substituents or optionally substituted fused rings, wherein a nitrile of the formula II EQU nc -- ch.sub.2 -- y (ii) is reacted, in organic solvents, with a lower alcohol of the formula III EQU r -- oh (iii) using a molar ratio of nitrile to alcohol of 1:0.9 to 1:1.2, in the presence of an anhydrous strong acid at temperatures of -10.degree. to +40.degree. C to give an imino-ether salt of the formula IV ##STR3## and the resulting imino-ether salt is subjected, without intermediate isolation thereof, to a condensation reaction with an aromatic amine of the formula V ##STR4## using a molar ratio of nitrile to amine of the formula V of 1:0.8 to 1:1.2, at temperatures of 0.degree. to 120.degree. C to give compounds…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.