Processes for preparing calixarenes

1. A process for the selective synthesis of a calix[8]arene compound, comprising:

reacting a phenolic compound, an aldehyde, and a nitrogen-containing base as a catalyst, in the presence of an organic solvent; and

heating the reaction mixture at an elevated temperature to remove water from the reaction mixture and selectively produce a calixarene compound containing at least 70% calix[8]arene.

2. The process of claim 1 , wherein:

the reacting step is carried out under reflux conditions, for a time period of 10 hours or longer; and

the heating step is carried out at an elevated temperature of about 140° C. to about 180° C. for a time period of 4 hours or longer.

3. The process of claim 1 , wherein the heating step at the water removal stage is carried out over a time period of 6 hours or longer to selectively produce a calixarene compound containing at least 90% calix[8]arene.

4. The process of claim 1 , wherein the elevated temperature at the water removal stage ranges from about 140° C. to about 150° C.

5. The process of claim 1 , wherein the phenolic compound is phenol, an alkyl phenol, or an arylalkyl phenol.

6. The process of claim 5 , wherein the phenolic compound is a para-C 1 -C 24 alkyl phenol, benzyl phenol, or cumyl phenol.

7. The process of claim 1 , wherein the aldehyde is formaldehyde or paraformaldehyde.

8. A process for a one-step, selective synthesis of a high-purity calix[8]arene compound, comprising:

reacting, in a one-step process, a phenolic compound and an aldehyde in the presence of a base catalyst to form a high-purity calix[8]arene compound, without carrying out a recrystallization step; and

filtrating the reaction product and drying the filtrated reaction product, thereby producing a calix[8]arene compound with a purity of about 90% or higher.

9. The process of claim 8 ,

wherein the filtrating and drying produce a calix[8]arene compound with a purity of about 95% or higher.

10. The process of claim 8 ,

wherein the filtrating and drying produce a calix[8]arene compound with a purity of about 98% or higher.

11. The process of claim 8 , wherein the phenolic compound is an alkyl phenol, an alkyl phenol, or an arylalkyl phenol.

12. The process of claim 11 , wherein the phenolic compound is a para-C 1 -C 24 alkyl phenol, benzyl phenol, or cumyl phenol.

13. The process of claim 8 , wherein the aldehyde is formaldehyde or paraformaldehyde.

14. A process for the selective synthesis of a calix[8]arene compound with a low free phenolic monomer content, comprising:

reacting a phenolic compound and an aldehyde in the presence of a base catalyst, and

washing the reaction product to remove free phenolic compound monomers, to produce a calix[8]arene compound with a free phenolic monomer content of about 0.5% or lower,

wherein the process does not include a recrystallization step.

15. The process of claim 14 , wherein the free phenolic monomer content is about 0.1% or lower.

16. The process of claim 14 , further comprising:

filtrating the washed reaction product and drying the filtrated reaction product, thereby producing a high-purity calix[8]arene compound with a purity of about 95% or higher.

17. The process of claim 14 , wherein the phenolic compound is an alkyl phenol, an alkyl phenol, or an arylalkyl phenol.

18. The process of claim 17 , wherein the phenolic compound is a para-C 1 -C 24 alkyl phenol, benzyl phenol, or cumyl phenol.

19. The process of claim 14 , wherein the aldehyde is formaldehyde or paraformaldehyde.

20. A phenolic oligomer composition prepared by the process of claim 1 .

21. A phenolic oligomer composition prepared by the process of claim 8 .

22. A phenolic oligomer composition prepared by the process of claim 14 .