Lonza Inc.

Burkhard Thierrichter

Hans Junek

Process for the production of 4,6-diamino-5-cyano-3-aryl-isoxazole [5,4-b] pyridines having the formula: ##STR1## wherein (a) R.sup.1 and R.sup.2 are --H or (b) R.sup.1 is --Cl and R.sup.2 is --H, or (c) R.sup.1 is --CH.sub.3 and R.sup.2 is --H or (d) R.sup.1 is --NO.sub.2 and R.sup.2 is --H, or (e) R.sup.1 is --H and R.sup.2 is --NO.sub.2. 2-Amino-1-propane-1,1,3-tricarbonitrile having the formula: ##STR2## is reacted with a benzohydroxamino acid chloride having the formula: ##STR3## wherein R.sup.1 and R.sup.2 have the same meaning as above, in the presence of a strong base in at least a molar quantity.

3-Amino-2-cyano-3-(5-amino-3-phenyl-isoxazole-4-yl)-acrylonitrile

An intermediate product of the formula ##STR1## is reacted with NaOH or KOH at 50.degree.-110.degree. to produce 4-amino-6-hydroxy-3-aryl-isoxazolo [5,4-b] pyridine-5-carbonitrile.

3-Amino-2-cyano-3-(5-amino-3-aryl-isoxazolo-4-yl)-acrylic acid methyl

Process for the production of 4,6-diamino-5-cyano-3-aryl-isoxazolo [5,4-b]

Process for the production of 4-amino-6-hydroxy-3-aryl isoxazolo [5,4-b] pyridine-5-carbonitriles having the formula: ##STR1## wherein R (a) is --H, (b) is --Cl or (c) is --CH.sub.3. 3-Amino-2,4,dicyanocrotonic acid methyl ester having the formula: ##STR2## is reacted with a benzohydroxyamino acid chloride having the formula: ##STR3## wherein R has the same meaning as above, in the presence of a strong base (at least molar) at a temperature of up to 10.degree. C. to produce, as an intermediate, the corresponding 3-amino-2-cyano-3-(5-amino-3-aryl-isoxazol-4-yl)-acrylic acid methyl ester having the formula ##STR4## wherein R has the same meaning as above. The intermediate product is reacted in excess diluted NaOH or KOH at a temperature of 50.degree. to 110.degree. C. to produce the corresponding 4-amino-6-hydroxy-3-aryl-isoxazolo [5,4-b] pyridine-5-carbonitrile.

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Burkhard Thierrichter