Claims
- 1. A method for the preparation of a tetraazaindene salt represented by the structural formula ##STR13## wherein R.sub.1 is selected from straight chain alkyl groups and aryl groups having up to about 8 carbon atoms, R.sub.2 is an alkyl or aryl group having up to about 8 carbon atoms, and M is a metal cation selected from Na, K, and mixtures thereof, comprising the steps of:
- (i) reacting a compound represented by the structural formula ##STR14## wherein R.sub.3 and R.sub.4 are independently selected from alkyl groups having up to about 4 carbon atoms with an orthoester represented by the structural formula R.sub.1 --C(OR).sub.3 wherein R.sub.1 is as defined hereinabove and R is an alkyl group having up to about 4 carbon atoms in the presence of (a) a catalytic amount of a tertiary amine having a pKa sufficient to catalyze the reaction and (b) a substantially anhydrous organic solvent to form a first intermediate represented by the structural formula ##STR15## wherein R, R.sub.1, R.sub.3, and R.sub.4 are as described hereinabove; (ii) reacting said first intermediate with a triazole represented by the structural formula ##STR16## wherein R.sub.2 is as defined hereinabove to form a second intermediate represented by the structural formula ##STR17## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are as described hereinabove; and
- (iii) reacting said second intermediate with a base selected from the group consisting of NaOH, KOH, Na.sub.2 CO.sub.3, and K.sub.2 CO.sub.3, and mixtures thereof, at a reaction temperature in the range of from about 0.degree. C. to about 50.degree. C., to form said tetraazaindene salt having Formula I.
- 2. The method of claim 1 wherein said tertiary amine in step (i) is pyridine.
- 3. The method of claim 1 wherein said compound of Formula IV is cyclic dimethylmethylene malonate.
- 4. The method of claim 1 wherein said substantially anhydrous organic solvent is ethyl acetate.
- 5. The method of claim 1 wherein said triazole is 3-amino-5-methylthio-1,2,4-triazole.
- 6. The method of claim 1 wherein said orthoester is triethylorthoacetate.
- 7. The method of claim 1, further comprising the step of reacting said compound of Formula I with an acid to form a compound represented by the structural formula ##STR18##
- 8. A method for the preparation of a tetraazaindene salt represented by the structural formula ##STR19## comprising the steps of: (i) reacting Meldrum's acid with triethylorthoacetate in the presence of pyridine and ethylacetate to form a first intermediate represented by the structural formula ##STR20## (ii) reacting said first intermediate with 3-amino-5-methylthio-1,2,4-triazole to form a second intermediate represented by the structural formula ##STR21## and, (iii) reacting said second intermediate with sodium carbonate to form said tetraazaindene salt.
- 9. The method of claim 8 further comprising the step of reacting said tetraazaindene salt with an acid to form the tetraazaindene represented by the structural formula ##STR22##
Parent Case Info
This application is a continuation of application Ser. No. 678,776 filed Apr. 1, 1991 and now U.S. Pat. No. 5,103,016, which was a division of application Ser. No. 542,621 filed Jun. 25, 1990 and now U.S. Pat. No. 5,061,799.
US Referenced Citations (4)
Divisions (1)
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542621 |
Jun 1990 |
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Continuations (1)
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678776 |
Apr 1991 |
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