Controlled feed process for making 3, 5-diaminobenzotrifluoride

Claim 1

A method of making 3,5-diaminobenzotrifluoride comprising: (1) preparing a solution of 4-chloro-3,5-dinitrobenzotrifluoride in a 1-alkanol; (2) preparing a slurry which comprises (a) a palladium catalyst on a suitable substrate; (b) at least one equivalent of magnesium oxide per equivalent of said 4-chloro-3,5-dinitrobenzotrifluoride; (c) sufficient hydrogen-donating reducing agent to reduce said 4-chloro-3,5-dinitrobenzotrifluoride to said 3,5-diaminobenzotrifluoride; and (d) an amount of said alkanol sufficient to make said slurry stirrable; (3) adding said solution to said slurry with stirring at a rate that does not exceed the reaction rate of said 4-chloro-3,5-dinitrobenzotrifluoride.

Claim 2

A method of making 3,5-diaminobenzotrifluoride comprising: (1) preparing a solution of 4-chloro-3,5-dinitrobenzotrifluoride in a 1-alkanol; (2) preparing a slurry which comprises (a) a palladium catalyst on a suitable substrate; (b) at least one equivalent of magnesium oxide per equivalent of said 4-chloro-3,5-dinitrobenzotrifluoride; (c) sufficient hydrogen-donating reducing agent to reduce said 4-chloro-3,5-dinitrobenzotrifluoride to said 3,5-diaminobenzotrifluoride; and (d) an amount of said alkanol sufficient to make said slurry stirrable; (3) adding said solution to said slurry with stirring at a rate that does not exceed the reaction rate of said 4-chloro-3,5-dinitrobenzotrifluoride.

Claim 18

A method of making 3,5-diaminobenzotrifluoride comprising (1) preparing a solution in methanol of about 5 to about 30% by weight 4-chloro-3,5-dinitrobenzotrifluoride; (2) charging a reactor with (a) about 1 to about 2 equivalents of magnesium oxide per mole of said 4-chloro-3,5-dinitrobenzotrifluoride; and (b) about 5 to about 10% by weight of a catalyst comprising about 1 to about 10% by weight palladium on carbon; (3) purging said reactor with nitrogen; (4) adding sufficient methanol to said reactor to form a slurry of said magnesium oxide and said catalyst; (5) stirring said methanol, magnesium oxide, and catalyst in said reactor to form said slurry; (6) adding at least 7 moles of hydrogen to said reactor per mole of said 4-chloro-3,5-dinitrobenzotrifluoride at a pressure of about 50 to about 100 psi; (7) adding said solution to said reactor with stirring at a rate that does not exceed its reaction rate, so that unreacted 4-chloro-3,5-dinitrobenzotrifluoride does not accumulate in said reactor; (8) maintaining the temperature within said reactor at about 75° to about 100° C.; (9) after the addition of said solution, sampling the contents of said reactor to determine the progress of said reaction; and (10) when at least 90% of the 4-chloro-3,5-aminobenzotrifluoride intermediate formed by said reaction has been converted into 3,5-diaminobenzotrifluoride, stopping said stirring, allowing solids to settle, and decanting said solution from said reactor.

Claim 19

A method of making 3,5-diaminobenzotrifluoride comprising (1) preparing a solution in methanol of about 5 to about 30% by weight 4-chloro-3,5-dinitrobenzotrifluoride; (2) charging a reactor with (a) about 1 to about 2 equivalents of magnesium oxide per mole of said 4-chloro-3,5-dinitrobenzotrifluoride; and (b) about 5 to about 10% by weight of a catalyst comprising about 1 to about 10% by weight palladium on carbon; (3) purging said reactor with nitrogen; (4) adding sufficient methanol to said reactor to form a slurry of said magnesium oxide and said catalyst; (5) stirring said methanol, magnesium oxide, and catalyst in said reactor to form said slurry; (6) adding at least 7 moles of hydrogen to said reactor per mole of said 4-chloro-3,5-dinitrobenzotrifluoride at a pressure of about 50 to about 100 psi; (7) adding said solution to said reactor with stirring at a rate that does not exceed its reaction rate, so that unreacted 4-chloro-3,5-dinitrobenzotrifluoride does not accumulate in said reactor; (8) maintaining the temperature within said reactor at about 75° to about 100° C.; (9) after the addition of said solution, sampling the contents of said reactor to determine the progress of said reaction; and (10) when at least 90% of the 4-chloro-3,5-aminobenzotrifluoride intermediate formed by said reaction has been converted into 3,5-diaminobenzotrifluoride, stopping said stirring, allowing solids to settle, and decanting said solution from said reactor.