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Org. Synth. 1999, 76, 1
DOI: 10.15227/orgsyn.076.0001
RESOLUTION OF 1,1'-BI-2-NAPHTHOL
[ 1,1'-Binaphthalene]-2,2'-diol ]
Submitted by Dongwei Cai, David L. Hughes, Thomas R. Verhoeven, and Paul J. Reider1 .
Checked by Rachel van Rijn and Amos B. Smith, III.
Discussion Addendum: Org. Synth. 2014, 91, 1
1. Procedure
A 500-mL flask, equipped with a magnetic stirring bar and a reflux condenser, is charged with 1,1'-bi-2-naphthol (23.0 g, 80 mmol) and N-benzylcinchonidinium chloride (18.6 g, 44 mmol) (Note 1). Acetonitrile (300 mL) is added, and the resulting suspension is refluxed for 4 hr, cooled and stirred at room temperature overnight. The mixture is then cooled to 0–5°C, kept at that temperature for 2 hr, and filtered (Note 2). The filtrate is concentrated to dryness, redissolved in ethyl acetate (300 mL), and washed with 1 N hydrochloric acid (HCl, 2 × 100 mL) (Note 3) and brine (100 mL). The organic layer is dried over sodium sulfate (Na2SO4), filtered, and concentrated to a light brown solid [10.28–10.65 g, mp 205-206°C, 89-93% recovery, 99.0% ee S-enantiomer [α]21 D −27.6~−29.4° ( THF , c 1)] (Note 4), (Note 5), (Note 6).
The solid complex is washed with acetonitrile (50 mL). This acetonitrile solution is discarded because of the low ee (~80% ee of the S-enantiomer is contained). The resulting solid complex (96% ee, R-enantiomer) is transferred to a 250-mL flask. Methanol (100 mL) is added, and the resulting suspension is refluxed for 24 hr to upgrade the enantiomeric excess to >99% ee. After the mixture is cooled to room temperature, it is filtered and the solid washed with methanol (20 mL). The solid complex is suspended in a mixture of ethyl acetate (300 mL) and 1 N HCl (150 mL) and stirred until complete dissolution occurs (0.5 hr). The solution is transferred to a separatory funnel, and the organic layer is separated and then washed with 1 N HCl (150 mL) and brine (150 mL). The organic layer is dried over Na2SO4, filtered, and concentrated to an off-white crystalline solid [9.83-10.16 g, 85-88% recovery, mp 206-207°C, >99.8% ee of the R-enantiomer [α]21 D 26.2~30.9° (THF, c 1)] (Note 4), (Note 5), (Note 6).
2. Notes
1. Racemic 1,1'-bi-2-naphthol and N-benzylcinchonidinium chloride were purchased from Aldrich Chemical Company, Inc. , acetonitrile (LC grade) was obtained from Fisher Scientific .
2. The enantiomeric excess of 1,1'-bi-2-naphthol in the filtrate at room temperature is 98.6% and at 0-5°C 99.0%.
3. These acid washes are to remove residual N-benzylcinchonidinium chloride in the filtrate.
4. Numerous chiral HPLC columns have been used for determination of chiral purity of 1,1'-bi-2-naphthol.2,3 The submitters used Diacel Chiralpak OP(+) column (4.6 mm × 250 mm) at room temperature for their chiral assay. Typical retention times of 1,1'-bi-2-naphthol are 14 min (R-enantiomer) and 20 min (S-enantiomer) using methanol as an eluting solvent at 0.5 mL/min. The submitters' detection limit of minor enantiomers is about 0.1%. The checkers used a Pirkle covalent D-phenylglycine column using isopropyl alcohol:hexane (5:95) as the eluting solvent at 1.0 mL/min with UV at 312 nm.
5. Enrichment to >99.8% ee is possible by recrystallization from a tert-butyl methyl ether (MTBE)/hexane mixture: 1.0 g of (S)-1,1'-bi-2-naphthol is dissolved in MTBE (10 mL), then hexane is added (20 mL). The resulting solid is stirred at room temperature for 2 hr, then filtered to provide a white crystalline solid (0.65 g, >99.8% ee, >99 wt% purity).
6. Other physical properties of the products are as follows: IR cm−1: 3550 (s), 3050 (m), 1610 (m), 1590 (m), 1390 (m), 1180 (s), 1140 (s) ; 1H NMR (250 MHz, CDCl3) δ: 5.0 (s, 2 H, OH), 7.16 (d, 2 H, J = 8.3), 7.30 (m, 2 H), 7.38 (m, 4 H), 7.90 (d, 2 H, J = 8.1), 7.99 (d, 2 H, J = 8.9) ; 13C NMR (62.9 MHz, CDCl3) δ: 110.8, 117.8, 124.0, 124.2, 127.5, 128.4, 129.5, 131.4, 133.4, 152.8 ; HRMS (FAB, m-nitrobenzyl alcohol): R enantiomer, m/z 304.1335 [(M+NH4 +); calcd for C20H14O2+NH4 +: 304.1337]; S-enantiomer, m/z 304.1331 [(M+NH4 +); calcd for C20H14O2+NH4 +: 304.1337].
Handling and Disposal of Hazardous Chemicals
The procedures in this article are intended for use only by persons with prior training in experimental organic chemistry. All hazardous materials should be handled using the standard procedures for work with chemicals described in references such as "Prudent Practices in the Laboratory" (The National Academies Press, Washington, D.C., 2011 www.nap.edu). All chemical waste should be disposed of in accordance with local regulations. For general guidelines for the management of chemical waste, see Chapter 8 of Prudent Practices.
These procedures must be conducted at one's own risk. Organic Syntheses, Inc., its Editors, and its Board of Directors do not warrant or guarantee the safety of individuals using these procedures and hereby disclaim any liability for any injuries or damages claimed to have resulted from or related in any way to the procedures herein.
3. Discussion
Both enantiomers of 1,1'-bi-2-naphthol are widely used for various applications: 1) chiral inducing agents for catalytic, asymmetric reactions such as the Diels-Alder reaction,4 ene reaction,5 6 or as Lewis acids;7 8 2) enantioselective reduction of ketones;9 10 3) synthesis of chiral macrocycles11 12 and other interesting compounds.13 Previously reported resolutions include: 1) making a cyclic phosphate of binaphthol, then resolution and subsequent reduction to release the pure binaphthol;14 2 15 16 17 18 2) using enzymatic hydrolysis of the diester of binaphthol;19 3 and 3) forming inclusion complexes with suitable compounds.20 21 22 The use of N-benzylcinchonidinium chloride to make inclusion complexes was reported by Tanaka and co-workers for obtaining one enantiomer of binaphthol.23 24 Using acetonitrile as solvent, in which the inclusion complex has very low solubility, allows for the isolation of both enantiomers with high enantiomeric excess. This simple and efficient procedure represents a much better resolution for 1,1'-bi-2-naphthol.25

References and Notes
  1. Merck Research Labs, P.O. Box 2000, Rahway, NJ 07065.
  2. Jacques, J.; Fouquey, C. Org. Synth., Coll. Vol. VIII 1993, 50;
  3. Kazlauskas, R. J. Org. Synth., Coll. Vol. IX 1998, 77.
  4. Bao, J.; Wulff, W. D.; Rheingold, A. L. J. Am. Chem. Soc. 1993, 115, 3814.
  5. Terada, M.; Motoyama, Y.; Mikami, K. Tetrahedron Lett. 1994, 35, 6693;
  6. Mikami, K.; Matsukawa, S. Tetrahedron Lett. 1994, 35, 3133.
  7. Sakane, S.; Maruoka, K.; Yamamoto, H. Tetrahedron Lett. 1985, 26, 5535;
  8. Maruoka, K.; Itoh, T.; Shirasaka, T.; Yamamoto, H. J. Am. Chem. Soc. 1988, 110, 310.
  9. Noyori, R.; Tomino, I.; Tanimoto, Y.; Nishizawa, M. J. Am. Chem. Soc. 1984, 106, 6709;
  10. Noyori, R.; Tomino, I.; Yamada, M.; Nishizawa, M. J. Am. Chem. Soc. 1984, 106, 6717.
  11. Sogah, G. D. Y.; Cram. D. J. J. Am. Chem. Soc. 1979, 101, 3035;
  12. Lehn, J.-M.; Simon, J.; Moradpour, A. Helv. Chim. Acta 1978, 61, 2407.
  13. Miyano, S.; Tobita, M.; Nawa, M.; Sato, S.; Hashimoto, H. J. Chem. Soc., Chem. Commun. 1980, 1233.
  14. Fabbri, D.; Delogu, G.; De Lucchi, O. J. Org. Chem. 1993, 58, 1748;
  15. Truesdale, L. K. Org. Synth., Coll. Vol. VIII 1993, 46;
  16. Kyba, E. P.; Gokel, G. W.; de Jong, F.; Koga, K.; Sousa, L. R.; Siegel, M. G.; Kaplan, L.; Sogah, G. D. Y.; Cram, D. J. J. Org. Chem. 1977, 42, 4173;
  17. Gong, B.-q.; Chen, W.-y.; Hu, B.-f. J. Org, Chem. 1991, 56, 423;
  18. Brunel, J.-M.; Buono, G. J. Org. Chem. 1993, 58, 7313.
  19. Kazlauskas, R. J. J. Am. Chem. Soc. 1989, 111, 4953;
  20. Toda, F.; Tanaka, K. J. Org. Chem. 1988, 53, 3607;
  21. Kawashima, M.; Hirata, R. Bull. Chem. Soc. Jpn. 1993, 66, 2002;
  22. Periasamy, M., Bhanu Prasad, A. S.; Bhaskar Kanth, J. V.; Reddy, C. K. Tetrahedron: Asymmetry 1995, 6, 341.
  23. Tanaka, K.; Okada, T.; Toda, F. Angew. Chem., Int. Ed. Engl. 1993, 32, 1147;
  24. Toda, F.; Tanaka, K.; Stein, Z.; Goldberg, I. J. Org. Chem. 1994, 59, 5748.
  25. Cai, D.; Hughes, D. L.; Verhoeven, T. R.; Reider, P. J. Tetrahedron Lett. 1995, 36, 7991.

Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

1,1'-Bi-2-naphthol:
[1,1'-Binaphthalene]-2,2'-diol (8,9); (602-09-5)

N-Benzylcinchonidinium chloride:
Cinchonanium, 9-hydroxy-1-(phenylmethyl)-, chloride, (9S)- (10); (69221-14-3)

Acetonitrile: TOXIC (8,9); (75-05-8)

(S)-(-)-1,1'-Bi-2-naphthol:
[1,1'-Binaphthalene]-2,2'-diol, (S)-(-)- (8);
[1,1'-Binaphthalene]-2,2'-diol, (S)- (9); (1853-99-2)

(R)-(+)-1,1'-Bi-2-naphthol:
[1,1'-Binaphthalene]-2,2'-diol, (R)-(+)- (8);
[1,1'-Binaphthalene]-2,2'-diol, (R)- (9); (18531-94-7)