Thiocarbonylthio compounds as chain transfer agents suitable for raft polymerization

Patent metadata

Field	Value
Publication number	US-10968173-B2
Application number	US-201716315432-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 7, 2016
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

The present invention relates to a compound having the structure of formula (I), wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 are as described herein. The present invention also relates to a process for the preparation of a compound of formula (I) and to a process for the synthesis of a polymer using the compound of formula (I) through controlled free radical polymerization.

First claim

What is claimed:

1. A compound having the structure of formula (I):

wherein
R 1 is aryl or SC 1-20 alkyl, wherein the aryl and SC 1-20 alkyl can be optionally substituted with 1-5 substituents independently selected in each occurrence thereof from the group consisting of H, C 1-6 alkyl, halogen, —OR 5 , —SR 5 , and —NR 6 R 7 ,
R 2 is C 1-6 alkyl,
R 3 is H or C 1-6 alkyl,
R 4 is H or C 1-6 alkyl,
R 5 is H or C 1-6 alkyl,
R 6 is H or C 1-6 alkyl, and
R 7 is H or C 1-6 alkyl,

with the proviso that when R 4 is methyl then R 1 is not aryl or —S-t-Bu.

2. The compound of claim 1 having the structure selected from the group consisting of:

3. A process for the preparation of a compound of formula (I):

wherein
R 1 is aryl or —SC 1-20 alkyl, wherein the aryl and —SC 1-20 alkyl can be optionally substituted with 1-5 substituents independently selected in each occurrence thereof from the group consisting of H,
C 1-6 alkyl, halogen, —OR 5 , —SR 5 , and —NR 6 R 7 ,
R 2 is C 1-6 alkyl,
R 3 is H or C 1-6 alkyl,
R 4 is H or C 1-6 alkyl,
R 5 is H or C 1-6 alkyl,
R 6 is H or C 1-6 alkyl, and
R 7 is H or C 1-6 alkyl,

with the proviso that when R 4 is methyl then R 1 is not aryl or —S-t-Bu, said process comprising:
providing a first intermediate compound of formula (II):

wherein A 1 ⊕ is a suitable cation; and
forming the compound of formula (I) from the first intermediate compound of formula (II).

4. The process according to claim 3 , wherein A 1 ⊕ is selected from the group consisting of K + , Na + , Li + , triethyl ammonium cation, and piperidinium cation.

5. The process according to claim 3 , wherein said forming the compound of formula (I) comprises:
reacting the first intermediate compound of formula (II) with a compound of formula (III):

wherein X is a leaving group,
under conditions effective to produce the compound of formula (I).

6. The process according to claim 5 , wherein X is a halogen.

7. The process according to claim 6 , wherein X is Cl.

8. The process according to claim 3 further comprising:
providing a second intermediate compound of formula (IV)
R 1 ⊖ A 2 ⊕   (IV),

wherein A 2 ⊕ is a suitable cation; and
forming the first intermediate compound of formula (II) from the second intermediate compound of formula (IV).

9. The process according to claim 8 , wherein A 2 ⊕ is selected from the group consisting of K + , Na + , Li + , triethyl ammonium cation, and piperidinium cation.

10. The process according to claim 8 , wherein said forming the first intermediate compound of formula (II) comprises:
reacting the second intermediate compound of formula (IV) with carbon disulfide under conditions effective to produce the first intermediate compound of formula (II).

11. The process according to claim 8 further comprising:
providing a compound of formula (V):
R 1 H  (V), and

reacting the compound of formula (V) with a base to form the second intermediate compound of formula (IV).

12. The process according to claim 11 , wherein the base is selected from the group consisting of K 3 PO 4 *xH 2 O, Na 3 PO 4 *xH 2 O, Li 3 PO 4 , NaH, Et 3 N, piperidine, morpholine, alkali hydroxides; and wherein x is 0 to 10.

13. The process according to claim 12 , wherein the base is K 3 PO 4 *3H 2 O.

14. A process for the synthesis of a polymer comprising:
providing a monomer composition;
providing a chain transfer agent of formula (I):

wherein
R 1 is aryl or —SC 1-20 alkyl, wherein aryl and —SC 1-20 alkyl can be optionally substituted with 1-5 substituents independently selected in each occurrence thereof from the group consisting of H,
C 1-6 alkyl, halogen, —OR 5 , —SR 5 , and —NR 6 R 7 ,
R 2 is C 1-6 alkyl,
R 3 is H or C 1-6 alkyl,
R 4 is H or C 1-6 alkyl,
R 5 is H or C 1-6 alkyl,
R 6 is H or C 1-6 alkyl, and
R 7 is H or C 1-6 alkyl; and
polymerizing the monomer composition through controlled free radical polymerization with the chain transfer agent to form the polymer.

15. The process of claim 14 , wherein the chain transfer agent has formula (I):

wherein
R 1 is aryl or —SC 1-20 alkyl, wherein aryl and —SC 1-20 alkyl can be optionally substituted with 1-5 substituents independently selected in each occurrence thereof from the group consisting of H,
C 1-6 alkyl, halogen, —OR 5 , —SR 5 , and —NR 6 R 7 ,
R 2 is C 1-6 alkyl,
R 3 is H or C 1-6 alkyl,
R 4 is H or C 1-6 alkyl,
R 5 is H or C 1-6 alkyl,
R 6 is H or C 1-6 alkyl, and
R 7 is H or C 1-6 alkyl,

with the proviso that when R 4 is methyl then R 1 is not aryl or —S-t-Bu.

16. The process of claim 14 , wherein the chain transfer agent has the structure selected from the group consisting of:

17. The process of claim 14 , wherein said monomer composition comprises one or more monomers.

18. The process of claim 17 , wherein the one or more monomers is selected from the group consisting of vinyl aromatics, acrylate, and methacrylate.

19. The process of claim 17 , wherein the one or more monomers is selected from the group consisting of styrene, butyl acrylate, methyl acrylate, and methyl methacrylate.

20. The process of claim 14 , wherein said polymerizing is carried out by reversible addition-fragmentation chain-transfer polymerization (RAFT), in the presence of a free radical initiator and a solvent.

21. The process of claim 20 , wherein said polymerizing is carried out at a temperature of 0 to 200° C.

22. The process of claim 20 , wherein said solvent is selected from the group consisting of toluene, THF, chloroform, cyclohexane, dioxane, dimethyl sulfoxide, dimethyl formamide, acetone, acetonitrile, n-butanol, n-pentanol, chlorobenzene, dichloromethane, diethylether, tert-butanol, 1,2,-dichloroethylene, diisopropylether, ethanol, ethylacetate, ethylmethylketone, heptane, hexane, isopropylalcohol, isoamylalcohol, methanol, pentane, n-propylalcohol, pentachloroethane, 1,1,2,2,-tetrachloroethane, 1,1,1,-trichloroethane, tetrachloroethylene, tetrachloromethane, trichloroethylene, water, xylene, benzene, nitromethane, glycerol, and a mixture thereof.

23. The process of claim 20 , wherein said solvent further includes stabilizers, surfactants, or dispersants.

24. The process of claim 20 , wherein the free radical initiator is selected from the group consisting of benzoyl peroxide and azobisisobutyronitrile.

25. The process of claim 14 , wherein said polymerizing is carried out in a solvent with the monomer having

Assignees

• Univ Iowa State Res Found Inc

Inventors

• Cochran Eric W
• Hernandez Nacu
• Forrester Michael
• Hohmann Austin

Classifications

• C07C329/00

  Thiocarbonic acids; Halides, esters or anhydrides thereof · CPC title

• C08F2438/02

  Stable Free Radical Polymerisation [SFRP]; Nitroxide Mediated Polymerisation [NMP] for, e.g. using 2,2,6,6-tetramethylpiperidine-1-oxyl [TEMPO] · CPC title

• C07D207/327

  Radicals substituted by carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals · CPC title

• C08F293/005

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• C07C327/36 Primary

  Esters of dithiocarboxylic acids · CPC title