Controlled feed process for making 3, 5-diaminobenzotrifluoride

A controlled feed process for making 3,5-diaminobenzotrifluoride from 4-chloro-3,5-dinitrobenzotrifluoride comprising:

• (1) preparing a solution in methanol of less than about 0.3 g/mL of 4-chloro-3,5-dinitrobenzotrifluoride;
• (2) preparing, in a reactor, a slurry which comprises
• (a) a catalytic amount of a palladium on carbon catalyst;
• (b) 1 to about 2 equivalents of MgO per equivalent of said 4-chloro-2,5-dinitrobenzotrifluoride;
• and
• (c) sufficient methanol to form said slurry;
• (3) purging said reactor with an inert gas;
• (4) admitting to said reactor under a pressure of about 50 to about 100 psi at least about 7 moles of hydrogen gas per mole of said 4-chloro-2,5-dinitrobenzotrifluoride;
• (5) adding said solution to said reactor at a rate sufficiently slow to prevent the accumulation of unreacted 4-chloro-3,5-dinitrobenzotrifluoride;
• and
• (6) maintaining the temperature in said reactor at about 75.degree. to about 100.degree. C.

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.degree. to about 100.degree. 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.