Method for the preparation of alkylsalicylaldehyde and alkylsalicylaldoxime, and use thereof

Abstract

The invention relates to an improved method for the preparation of alkylsalicylaldehyde or its corresponding metallic salts. The invention also relates to a method for the preparation of alkylsalicylaldoxime by reacting said alkylsalicylaldehyde or its corresponding metallic salts with hydroxylamine or its salt. The invention also relates to a method for extracting a metal in an aqueous solution containing dissolved metal.

Claims

1. A process for the preparation of an alkylsalicylaldehyde of formula (I) or its corresponding metallic salts of formula (II) ##STR00007## which comprises the following step: a/ reacting a phenolic compound of formula (III) ##STR00008## with formaldehyde or a formaldehyde liberating compound, in the presence of: a solvent selected from the group consisting of heptane, octane, nonane, decane, undecane, dodecane, tridecane, their isomers, and mixtures thereof; and a magnesium based reactant; wherein each of R1, R2 and R3, independently, are selected from the group consisting of hydrogen atom; halogen atom; hydroxy group; C6-C12 alkyl group; C6-C12 cycloalkyl group; C6-C12 alkoxyl group; C6-C12 acyl group; C6-C12 aryl group; C12 araryl group; C7-C12 alkaryl group; and OR5 wherein R5 is a C1-C22 linear or branched alkyl group, C2-C22 linear or branched alkenyl groups, C6 aryl group, or C7-C22 aralkyl group; wherein R4 is selected from the group consisting of hydrogen atom; C1 -C22 linear or branched alkyl group; C2-C22 linear or branched alkenyl group; C6 aryl group; C7-C22 aralkyl group; OH; and OR5 wherein R5 is a C1-C22 linear or branched alkyl group, C2-C22 linear or branched alkenyl group, C6 aryl group, or C7-C22 aralkyl group; wherein M is magnesium; and wherein x is 2.

2. The process according to claim 1, wherein the solvent is selected from the group consisting of heptane, octane, nonane, decane, undecane, dodecane, tridecane, and mixtures thereof.

3. The process according to claim 1, wherein the solvent is selected from the group consisting of nonane, decane, undecane, dodecane, tridecane, their isomers, and mixtures thereof.

4. The process according to claim 1, wherein, in the phenolic compound of formula (III), R1R3H, R2C9-C12 alkyl, and R4H or CH.sub.3.

5. The process according to claim 1, wherein during step a/, the weight ratio between the alkane solvent and the sum of alkylsalicylaldehyde of formula (I) and (II) and phenolic compound of formula (III) is continuously maintained between 0.5 and 10.

6. The process according to claim 1, wherein, when step a/ is started, the molar ratio between the magnesium based reactant and the phenolic compound of formula (III) is from 0.3 to 3.

7. The process according to claim 1, wherein the molar ratio between formaldehyde or a formaldehyde liberating compound and the phenolic compound of formula (III) is from 2 to 5.

8. A process for the preparation of an alkylsalicylaldoxime of formula (VIII) or its corresponding metallic salts of formula (IX): ##STR00009## which comprises the following steps: a/ preparing an alkylsalicylaldehyde of formula (I) or its corresponding metallic salts of formula (II) ##STR00010## by reacting a phenolic compound of formula (III) ##STR00011## with formaldehyde or a formaldehyde liberating compound, in the presence of: a solvent selected from the group consisting of heptane, octane, nonane, decane, undecane, dodecane, tridecane, their isomers, and mixtures thereof; and a magnesium based reactant; wherein each of R1, R2, and R3, independently, are selected from the group consisting of hydrogen atom; halogen atom; hydroxy group; C6-C12 alkyl group; C6-C12 cycloalkyl group; C6-C12 alkoxyl group; C6-C12 acyl group; C6-C12 aryl group; C12 araryl group; C7-C12 alkaryl group; and OR5 wherein R5 is a C1-C22 linear or branched alkyl group, C2-C22 linear or branched alkenyl groups, C6 aryl group, or C7-C22 aralkyl group; wherein R4 is selected from the group consisting of hydrogen atom; C1-C22 linear or branched alkyl group; C2-C22 linear or branched alkenyl group; C6 aryl group; C7-C22 aralkyl group; OH; and OR5 wherein R5 is a C1-C22 linear or branched alkyl group, C2-C22 linear or branched alkenyl groups, C6 aryl groups, or C7-C22 aralkyl group; wherein M is magnesium; and wherein x is 2; and b/ reacting the alkylsalicylaldehyde of formula (I) or its corresponding metallic salts of formula (II) resulting from step a/, with hydroxylamine or a salt of hydroxylamine.

9. The process according to claim 8, wherein step b/ is carried out between the alkylsalicylaldehyde of formula (I) and hydroxylamine or a salt of hydroxylamine.

10. The process according to claim 8, wherein the alkylsalicylaldehyde of formula (I) resulting from step a/ is substantially non purified before reacting with hydroxylamine or a salt of hydroxylamine during step b/.

11. A method for extracting a metal M.sub.2 in an aqueous solution containing dissolved metal comprising the following steps: a/ preparing an alkylsalicylaldehyde of formula (I) or its corresponding metallic salts of formula (II) ##STR00012## by reacting a phenolic compound of formula (III) ##STR00013## with formaldehyde or a formaldehyde liberating compound, in the presence of: a solvent selected from the group consisting of heptane, octane, nonane, decane, undecane, dodecane, tridecane, their isomers, and mixtures thereof; and a magnesium based reactant; wherein each of R1, R2, and R3, independently, are selected from the group consisting of hydrogen atom; halogen atom; hydroxy group; C6-C12 alkyl group; C6-C12 cycloalkyl group; C6-C12 alkoxyl group; C6-C12 acyl group; C6-C12 aryl group; C12 araryl group; C7-C12 alkaryl group; and OR5 wherein R5 is a C1-C22 linear or branched alkyl group, C2-C22 linear or branched alkenyl group, C6 aryl group, or C7-C22 aralkyl group; wherein R4 is selected from the group consisting of hydrogen atom; C1-C22 linear or branched alkyl group; C2-C22 linear or branched alkenyl group; C6 aryl group; C7-C22 aralkyl group; OH; and OR5 wherein R5 is a C1-C22 linear or branched alkyl group, C2-C22 linear or branched alkenyl group, C6 aryl group, or C7-C22 aralkyl group; wherein M is magnesium; and wherein x is 2; b/ preparing an alkylsalicylaldoxime of formula (VIII): ##STR00014## by reacting the alkylsalicylaldehyde of formula (I) or its corresponding metallic salts of formula (II) resulting from step a/, with hydroxylamine or a salt of hydroxylamine; and c/ contacting an aqueous solution containing a metal M.sub.2 with a composition comprising the compound of formula (VIII) resulting from step b/.

12. The process according to claim 11, wherein the composition comprising the compound of formula (VIII) is a water-immiscible organic solution comprising a hydrocarbon solvent.

13. The process according to claim 11, wherein the metal M.sub.2 is copper.

14. The process according to claim 7, wherein the molar ratio between formaldehyde or a formaldehyde liberating compound and the phenolic compound of formula (III) is 2.25 to 3.25.

15. The process according to claim 3, wherein, in the phenolic compound of formula (III), R1R3H, R2C9-C12 alkyl, and R4H or CH.sub.3.

16. The process according to claim 15, wherein during step a/, the weight ratio between the alkane solvent and the sum of alkylsalicylaldehyde of formula (I) and (II) and phenolic compound of formula (III) is continuously maintained between 0.5 and 10.

17. The process according to claim 15, wherein, when step a/ is started, the molar ratio between the magnesium based reactant and the phenolic compound of formula (III) is from 0.3 to 3.

Description

EXAMPLES

Example 1

Invention

(1) A 1 liter glass reactor fitted with a temperature probe, a condenser and a stirring system is charged with 111.2 g of nonane, 50 g of methanol (1.56 mol), and 6.7 g of magnesium chips (0.28 mol). An activator solution, 7.4 ml of magnesium methoxide 7%, is added to activate the magnesium, and the mixture is heated to reflux temperature during 1 hour.

(2) After magnesium dissolution, the mixture is further heated under reflux during 1 h to ensure reaction completion; reaction end-point is observed when hydrogen gas production has ceased. This reaction affords magnesium methoxide, which is thereafter used as metal based reactant.

(3) 100 g of para-nonyl phenol (0.45 mol) is added to the resulting magnesium methoxide and the mixture is maintained under reflux for 0.5 hour to achieve formation of magnesium bis-nonylphenoxide.

(4) The condenser is then changed by a distillation head, and methanol/nonane azeotrope is evaporated during 1 hour until the mixture temperature reached 80 C. 58.4 g of distillate is obtained; it contains 90% of methanol by weight.

(5) The mixture is heated to 85 C. and 41 g of paraformaldehyde (1.36 mol) is added by portion over a period of 1 hour, with continuous removal of volatile product distillate. On completion of paraformaldehyde addition, the mixture is heated at 95 C. during 1 hour to ensure completion of reaction.

(6) The mixture is then cooled to approximately 50 C. A solution of 130 g of a 22% H.sub.2SO.sub.4 aqueous solution (0.29 mol) is added on top of the reaction mixture during 20 minutes.

(7) The aqueous layer (pH<1) is discarded while the organic layer is further washed 2 times with 100 g of fresh water during 20 minutes for each washing.

(8) The resulting organic layer is subjected to evaporation under vacuum with a wiped film evaporator to remove the nonane solvent. 106 g of crude nonylsalicylaldehyde is obtained, yield is 92%. The resulting nonylsalicylaldehyde is free of any aromatics and the residual nonane solvent amounts to less than 0.1% by weight.

(9) The total batch cycle time is 6.5 hours.

Example 2

Counter-example

(10) A 1 liter glass reactor fitted with a temperature probe, a condenser and a stirring system is charged with 175.9 g of toluene, 57.6 g of methanol (1.79 mol) and 6.7 g of magnesium chips (0.28 mol). An activator solution, 7.4 ml of magnesium methoxide 7%, is added to activate the magnesium, and the mixture is heated to reflux temperature during 1 hour.

(11) After magnesium dissolution, the mixture is further heated under reflux during 1 hour to ensure reaction completion; reaction end-point is observed when hydrogen gas production has ceased.

(12) 100 g of para-nonyl phenol (0.45 mol) is added and the mixture is maintained under reflux for 0.5 hour to achieve formation of magnesium bis-nonylphenoxide.

(13) The condenser is then substituted by a distillation head, and methanol/toluene azeotrope is evaporated during 2 hours until the mixture temperature reached 80 C. 84 g of distillate is obtained; it contains 69% of methanol by weight.

(14) The resulting mixture is heated to 90 C. and 41 g of paraformaldehyde (1.36 mol) is added by portion over a period of 3 hours, with continuous removal of volatile product distillate. On completion of paraformaldehyde addition, the mixture is heated at 95 C. during 1 hour to ensure completion of the reaction.

(15) The mixture is then cooled to approximately 50 C. A solution of 130 g of a 22% H.sub.2SO.sub.4 aqueous solution (0.29 mol) is added on top of the reaction mixture during 20 minutes.

(16) The aqueous layer (pH<1) is discarded while the organic layer is further washed 2 times with 100 g of fresh water during 20 minutes for each washing.

(17) The resulting organic layer is subjected to evaporation under vacuum with a wiped film evaporator to remove the toluene solvent. 102 g of crude nonylsalicylaldehyde is obtained. Yield is 90%. The resulting nonylsalicylaldehyde contains 1% of toluene.

(18) The total batch cycle time is 9.5 hours.

Example 3

Oximation Process

(19) 68 g of nonylsalicyladehyde (0.27 mol) obtained according to example 1, 55.5 g of water (3.03 mol), 23.5 g of 50% a caustic (NaOH) solution (0.29 mol), 12.7 g of Escaid 110 (C7-C13 hydrocarbon fluid, trademark of ExxonMobil) 110, 26.9 g of trimethyl pentanyl diisobutyrate (TXIB trademark of Eastman company) and 23.4 g of hydroxylamine sulfate (0.14 mol) are mixed in a 4 neck round flask. The mixture is heated at 65 C. and stirred until nonylsalicylaldehyde is converted to the corresponding nonylsalicylaldoxime (indicated by FTIR by disappearance of the CHO band at 1655 cm.sup.1).

(20) The mixture is settled and the aqueous phase is discarded. The organic phase is washed with 80 g of a 6% sulfuric acid aqueous solution.

(21) The organic layer is further washed 2 times with 80 g of fresh water.

(22) The resulting organic solution is dried over sodium sulphate. The desired product nonylsalicylaldoxime is obtained as a pale yellow oil.