Claims
- 1. A process for preparing a compound having the formula I: ##STR38## wherein R.sub.1 is hydrogen, 1 to 6 carbon lower alkyl, phenyl, mono-nitro-substituted phenyl wherein the nitro group is in the ortho or para position, or naphthyl, which comprises the steps of reacting a compound of the formula II: ##STR39## with a compound having the formula ##STR40## wherein R.sub.1 is as defined above, to obtain an intermediate acid having the formula III: ##STR41## wherein R.sub.1 is as defined above; and cyclizing the intermediate acid by the addition of an acid catalyst selected from the group consisting of sulfuric acid, trifluoroacetic acid, and polyphosphoric acid.
Parent Case Info
This is a division of application Ser. No. 468,349 filed May 9, 1974, now U.S. Pat. No. 3,971,806 issued July 27, 1976.
US Referenced Citations (3)
Non-Patent Literature Citations (1)
Entry |
Noller; Chem. of Org. Compounds; pp. 304; 611 (1965). |
Divisions (1)
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Number |
Date |
Country |
Parent |
468349 |
May 1974 |
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