The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 17, 1978
Filed:
Jun. 01, 1976
Sumitomo Chemical Company, Limited, Osaka, JA;
Abstract
An improved process for preparing indole derivatives of the formula, ##STR1## wherein R.sub.1 and R.sub.2 each are hydrogen, halogen, C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 alkoxy, nitro, cyano or trifluoromethyl, or when taken together, form methylenedioxy; R.sub.3 is hydrogen, halogen, C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 alkoxy, nitro, cyano or dimethylamino; and R.sub.4 is hydrogen or halogen, which comprises cyclizing a compound of the formula, ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are as defined above, with an acidic condensing agent. The indole derivatives of the formula (I) mentioned above are useful as a key intermediate for the preparation of benzodiazepines, which are useful as tranquilizers, muscle relaxants and the like.