Processes for the preparation of cyclopropanecarboxylic acid and derivatives thereof

Abstract

Disclosed is a process for the preparation of cyclopropanecarboxylic acid by the non-catalytic, oxidation of cyclopropanecarboxaldehyde using molecular oxygen as the oxidant. Also disclosed are processes for the preparation of amides, esters and acid chlorides from cyclopropanecarboxylic acid.

We claim:  
     
       1. Process for the preparation of cyclopropanecarboxylic acid which comprises contacting cyclopropanecarboxaldehyde with molecular oxygen at a temperature of about 10° to 200° C. wherein in a second step the cyclopropanecarboxylic acid is reacted with a hydroxy compound having the structure R—OH in the presence of an acidic catalyst to produce a cyclopropanecarboxylate ester having the structure:                    
       wherein R is (i) a linear or branched alkyl, alkenyl or alkynyl radical containing up to about 30 carbon atoms, (ii) a cycloalkyl or cycloalkenyl radical containing 3 to 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. 
     
     
       2. Process for the preparation of cyclopropanecarboxylic acid which comprises contacting cyclopropanecarboxaldehyde with molecular oxygen provided as substantially pure oxygen, air, or oxygen-enriched air at a temperature of about 50° to 100° C. and a pressure of about 1 to 10 bar absolute in the absence of an oxidation catalyst wherein in a second step the cyclopropanecarboxylic acid is reacted with a primary or secondary alkanol containing up to about 8 carbon atoms at a temperature of about 60° to 150° C. in the presence of an acidic catalyst to produce an alkyl cyclopropanecarboxylate. 
     
     
       3. Process for the preparation of cyclopropanecarboxylic acid which comprises contacting cyclopropanecarboxaldehyde with molecular oxygen at a temperature of about 10° to 200° C. wherein in a second step the cyclopropanecarboxylic acid is reacted with ammonia at a temperature of about 20° to 400° C. and a pressure of about 1 to 345 bar absolute to produce cyclopropanecarboxamide. 
     
     
       4. Process for the preparation of cyclopropanecarboxylic acid which comprises contacting cyclopropanecarboxaldehyde with molecular oxygen provided as substantially pure oxygen, air, or oxygen-enriched air at a temperature of about 50° to 100° C. and a pressure of about 1 to 10 bar absolute in the absence of an oxidation catalyst wherein in a second step the cyclopropanecarboxylic acid is reacted with ammonia at a temperature of about 180° to 260° C. and a pressure of about 10 to 100 bar absolute to produce cyclopropanecarboxamide. 
     
     
       5. Process for the preparation cyclopropanecarboxamide which comprises the steps of: 
       (1) contacting cyclopropanecarboxylic acid with ammonia in a reactor at a temperature of 200° to 260° C. and a pressure of 10 to 100 bar absolute in the absence of both a catalyst and a solvent to form a melt of cyclopropanecarboxamide;  
       (2) venting the reactor at a temperature above the melting point of cyclopropanecarboxamide to reduce the pressure to about atmospheric pressure and remove excess ammonia and water of reaction from the cyclopropanecarboxamide; and  
       (3) obtaining from the reactor cyclopropanecarboxamide essentially free of water and ammonia.  
     
     
       6. Process according to claim  5  wherein step (1) is performed at 230° to 240° C. and step (2) is performed at 130° to 150° C. 
     
     
       7. A process for the preparation of cyclopropanecarboxamide which comprises reacting cyclopropanecarboxylic acid with ammonia at a pressure of  1  to  345  bar in the presence of an organic solvent to give the amide. 
     
     
       8. The process of claim  7 , which is carried out in the absence of a catalyst. 
     
     
       9. The process of claim  7 , wherein at least one solvent selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons is used as the solvent. 
     
     
       10. The process of claim  7 , wherein the at least one solvent selected from the group consisting of cyclohexane, heptane, toluene, and xylene is used as the solvent. 
     
     
       11. The process of claim  7 , wherein at least one solvent selected from the group consisting of ethers and alcohols is used as the solvent. 
     
     
       12. The process of claim  7 , which is carried out at a pressure of  1  to  100  bar. 
     
     
       13. The process of claim  7 , wherein the reaction with ammonia is carried out in a temperature range from  20 ° to  400 ° C. 
     
     
       14. The process of claim  7 , wherein the amide is collected as a solids, washed and isolated by filtration.