Continuous process for the preparation of amines

• US 6,683,216 B1
• Filed: 11/06/2002
• Issued: 01/27/2004
• Est. Priority Date: 11/06/2002
• Status: Expired due to Fees

• Current Assignee: Eastman Chemical Company
• Original Assignee: Eastman Chemical Company
• Inventors: Bellner, Steven Paul, Buchanan, Norma Lindsey, Zoeller, Joseph Robert, Sharkey, Elizabeth Celia, Terrill, Daniel Latham
• Primary Examiner(s): BARTS, SAMUEL A
• Application Number:
  US10/289,016
• Time in Patent Office: 447 Days
• Field of Search: 564/448, 564/414, 564/488
• US Class Current: 564/448
• CPC Class Codes: C07C 209/58 from or via amides
• CPC Class Codes: C07C 211/35 containing only non-condensed rings
• CPC Class Codes: C07C 2601/02 with a three-membered ring

Abstract

Disclosed is a process for the preparation of amines by continuously feeding a carboxamide, aqueous alkaline hypohalite, and aqueous alkaline hydroxide to a first reaction zone to form a N-halocarboxamide, measuring the concentration of at least one reaction component in the effluent from the first reaction zone, and using the result of that measurement to control the feed rate of at least one of the feed components of to achieve at least 90% conversion of the carboxamide in the first reaction zone. The effluent from the first reaction zone is fed continuously to a second reaction zone where it further reacts to form an aqueous solution of an amine. The effluent from the second reaction zone may be fed continuously to a distillation column. The process is particularly useful for the preparation of cyclopropylamine.

Claims

1. Continuous process for the preparation of amines which comprises the steps of:

I. continuously feeding a carboxamide reactant, an aqueous alkaline hypohalite reactant, and an aqueous alkaline hydroxide reactant to a first reaction zone wherein the carboxamide, hypohalite, and hydroxide react to form a first reaction mixture comprising a plurality of components wherein at least one of the components is an N-halo-carboxamide;

II. continuously removing the first reaction mixture from the first reaction zone;

III. measuring the concentration of at least one component of the first reaction mixture and using the result of that measurement to control the feed rate of at least one of the reactants of step I to achieve at least 90% conversion of the carboxamide in the first reaction zone; and

IV. continuously feeding the first reaction mixture to a second reaction zone wherein the first reaction mixture further reacts to form a second reaction mixture comprising an aqueous solution of an amine.

2. Process according to claim 1 wherein the carboxamide of Step I has the structure:

wherein R is (i) a linear or branched alkyl, alkenyl, or alkynyl radical containing up to about 10 carbon atoms, (ii) a cycloalkyl or cycloalkenyl radical containing 3 to about 7 carbon atoms, (iii) a carbocyclic aromatic or heterocyclic aromatic radical which may carry one or more substituents, or (iv) a 5- or 6-membered non-aromatic heterocyclic radical comprising one or more hetero atoms selected from the group consisting of oxygen, nitrogen, phosphorus, and sulfur.

3. Process according to claim 2 wherein the carboxamide of Step I is about 5 wt % to about 90 wt % carboxamide in water, the aqueous alkaline hypohalite of Step I is about 3 wt % to about 17 wt % hypohalite, and the aqueous alkaline hydroxide of Step I is about 10 wt % to about 50 wt %. alkaline hydroxide.

4. Process according to claim 3 wherein the alkaline hypohalite is selected from the group consisting of lithium hypochlorite, lithium hypobromite, sodium hypochlorite, sodium hypobromite, potassium hypochlorite, potassium hypobromite, calcium hypochlorite, and calcium hypobromite;

and the alkaline metal hydroxide is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide.

5. Process according to claim 4 wherein the molar ratio of alkaline hypohalite to alkaline hydroxide fed to the first reaction zone is about 2:

1 moles hypohalite;

moles hydroxide.

6. Process according to claim 5 wherein the first reaction zone is maintained at a temperature of about 30°

C. up to about 55°

C. and a pressure of about 0 kilopascals up to about 2000 kilopascals gauge, and the second reaction zone is maintained at a temperature of about 60°

C. up to about 150°

C. and a pressure of about 0 kilopascals up to about 2000 kilopascals gauge.

7. Process according to claim 6 wherein the first reaction zone is a tubular reactor.

8. Process according to claim 7 wherein the measurement of reaction component concentrations of Step IV is carried out using UV-Visible spectroscopy, infrared spectroscopy, or a combination of UV-Visible and infrared spectroscopy.

9. A continuous process for the preparation of cyclopropylamines which comprises the steps of:

I. continuously feeding (i) an aqueous solution of a cyclopropanecarboxamide and (ii) a solution comprising sodium hypochlorite and sodium hydroxide to a first reaction zone comprising a tubular reactor, wherein the cyclopropanecarboxamide, sodium hypochlorite, and sodium hydroxide react to form a first reaction mixture comprising an N-chlorocyclopropanecarboxamide;

II. continuously removing the first reaction mixture from the first reaction zone;

III. measuring the concentration of sodium hypochlorite in the first reaction mixture using UV-Visible spectroscopy and using the result of that measurement to control the feed rate of at least one of the solutions (i) or (ii) of Step I to achieve at least 90% conversion of the cyclopropanecarboxamide in the first reaction zone; and

IV. continuously feeding the first reaction mixture from the first reaction zone to a second reaction zone wherein the first reaction mixture further reacts to form a second reaction mixture comprising an aqueous solution of a cyclopropylamine.

10. Process according to claim 9 wherein the feed rate of at least one of the solutions (i) or (ii) in Step III is controlled to maintain a concentration of hypochlorite of about 0.01 wt % up to about 0.02 wt % in the first reaction mixture.

11. Process according to claim 10 wherein the cyclopropanecarboxamide has the structure:

wherein R¹ and R² are independently selected from hydrogen, a linear or branched alkyl, alkenyl, or alkynyl radical containing up to about 6 carbon atoms.

12. Process according to claim 11 wherein the aqueous solution (i) of Step I is about 15 wt % up to about 55 wt % cyclopropanecarboxamide and the solution (ii) of Step I is about 7 up to about 15 wt % sodium hypochlorite and about 30 up to about 50 wt % sodium hydroxide.

13. Process according to claim 12 wherein the molar ratio of sodium hydroxide to sodium hypochlorite in feed solution (ii) of Step I is about 2:

1 up to about 3;

1 moles hydroxide;

moles hypochlorite.

14. Process according to claim 13 wherein the first reaction zone is maintained at a temperature of about 45°

C. up to about 55°

C. and a pressure of about 0 kilopascals up to about 2000 kilopascals gauge, and the second reaction zone is maintained at a temperature of about 70°

C. up to about 105°

C. and a pressure of about 0 kilopascals up to about 2000 kilopascals gauge.

15. Process according to claim 14 wherein the tubular reactor of Step I has a length to diameter ratio of at least 30:

1 and is operated under substantially adiabatic conditions.

16. Process according to claim 15 wherein the second reaction mixture is continuously fed into a distillation column having a top, middle, and base section.

17. Process according to claim 16 wherein a first distillate comprising the cyclopropylamine is continuously removed from the top section of the distillation column and a second distillate comprising mid-boiling organic impurities is continuously removed from the middle section of the distillation column.

18. Process according to claim 17 wherein R¹ and R² are hydrogen.