The 2nd International Conference on Chemical Sciences Proceeding ISSN NO. 1410-8313 Yogyakarta, October 14-16th, 2010

ISOLATION OF FROM RHODINOL BY USING PDC REAGENT NaHSO3 AND NaBH4

Zaina Mukhia Bintan, Priatmoko1,*), and Hardono Sastrohamidjojo*)

1 Department of Chemistry, Universitas Gadjah Mada, Yogyakarta, Indonesia

* Corresponding author, tel/fax : +62274545188

ABSTRACT

Isolation geraniol from the rhodinol have been coducted by using PDC (pyridinium dichromate) reagent, NaHSO3 and NaBH4. The prosses consits of four steps : first step was rhodinol to get the high grade (it are compare between citronella oil from sample A, sample B and sample C, second step was the oxidation of rhodinol by using PDC, third step was separation of citral from citronellol by using sodium bisulfit, and the last step was reduction of citral to geraiol by using NaBH4 in etanol. The higher grade rhodinol was isolated from citronella oil of sample with purity 29.03%. The rhodinol wich used in this research was product of the third fraction redistillation of distillate the second fraction citronella oil, with grade of rhodinol was 90.55%. The oxidation of rhodinol by using PDC, could selectively oxidize geraniol become citral, whereas nothing change with citronellol. The product of oxidation was mixture of citral and citronellol, yellow liquid with fragnance odor, weight : 0.8 g. The geraniol can be obtained from reduction geraniol by using NaBH4 in ethanol. Product of reduction was colourless liquid, with fragnance odor, weight : 0.4 g. The product was analyzed by using GC and infrared spectrometer.

Keywords: geraniol, citral, pyridinium dichromate

INTRODUCTION Schmidts (1979 have also made the reagent to oxidase alcohol (primary, secondary and so he essential oil is a natural product that on) become the carbonyl compound. much more used in an everyday live Rhodinol consist of mixture of citronellol Tanalogous to progress of technology, and geraniol, that the structure are shown in need to the principle essential oil the longer Figure 1. The isolation method of geraniol and the usage in principle in the drug industry, citronellol from mixture of rhodinol was perfumery industry and nice food. (Deva performed to react rhodinol with PDC in the Kumar at all, 1977) ethanol (oxidation reaction). The reaction and geraniol have the between geraniol and PDC in the ethanol structure near the same until physical and yields citral. (Solomon, 1950) chemical properties are also near the same each other. In isolation of the citronellal oil, citronellal and geraniol ordinary always found a mixture and cannot separated with distillation method. (Guinther E, 1950) The separation of the organic compound from the mixture can do by two method that CH2OH and CH2OH are the first method physical separation (extraction, distillation and chromatography), the second method with chemical separation (the reaction). (Furnish at all, 1989) In the oxidation reaction of alkene can result an epoxide or diol if without separation, citronellol geraniol the oxidation of alkene with separation can be resalted ketone, aldehyde or carboxylate acid. Figure 1. Structure of citronellol and geraniol The oxidation with separation can be used KMnO4 oxidator (heat), with KMnO4 oxidator (cool) are the oxidator without separation. (Fessenden and Fessenden, 1992) Corey and

Zaina Mukhia Bintan, et al 483 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada ISSN NO. 1410-8313 The 2nd International Conference on Chemical Sciences Proceeding Yogyakarta, October 14-16th, 2010

EXPERIMENTAL SECTION was evaporated by using buchi evaporator. Its yield was analyze by using GC-MS and IR Procedure spectrophotometer. The isolation of rhodinol from citronella oil Citral 0.8 gr was added in the three neck The citronella oil as much as 250 gr was flask completed with ball cooler and magnetic added in the three necks flask capacity 500 ml stirrer. NaBH4 0.1 gr in ethanol was added that completed with vigreuks column 50 cm droply. Then the mixture was heated at 70- long, Liebig cooler and three receiving adapter 80oC for 3 hours. After cooling, the yield of and manometer. The fractional distillation at reaction was evaporated. The residu that reduce preasure was conducted and will be obtained was washed with 10 ml aquadest and obtain the fraction of distillate. The yield that was extracted with ether. And the ether layer obtained was analyzed by using GC-MS, IR was separated and dried with anhydrous 1 spectrophotometer and H -NMR. Na2SO4. The yield that obtained citronellal. The yield analyzed by using GC-MS and IR Synthesis piridium chromate spectrophotometer. Crystal CrO3 25 gr was dissolved in 25 ml aquadest. The chromate solution was RESULT AND DISCUSSION dissolved in the three necks flask capacity 500 ml that completed with ball coolers, ice cooler, Selected of the trade citronella oil magnetic stirrer and separatory funnel. The sample of the trade citronella oil Pyridine as much as 20,15 gr (0.25 mole) was analyzed by using GC to know the contain pyridine added in the separatory funnel. of rhodinol (geraniol and citronellol). Pyridine was added in the chromate solution Chromatogram of trade citronella oil that must droply and the temperature was watched fixed contain of rhodinol as follow: at 30oC, stirred continuously. The mixture that happened was diluted with 100 ml acetone, than it was cooled at 20oC temperature for 3 hours. Crystal that obtained orange color was dried in the desiccator. The yield was analyzed with the color and melting points.

Synthesis citral from rhodinol The rhodinol 3 gr (50% geraniol) was diluted in DMF (N,N-dimethyl formamide) 6 ml than it was added to the three necks flask 100 ml with ball coolers, ice cooler and magnetic stirrer. Than it was added droply. Five gram PDC that was diluted in DMF 10 ml, stirred continuously with 50 ml aquadest was diluted. The yield of the reaction was extracted with Figure 2. Chromatogram of the trade citronella oil the mixture of ether:methane (1:1). The upper layer was gathered and evaporated. Than its residue was analyzed by using GC-MS and IR From the chromatogram (Figure 2) was spectrophotometer. looked at the peak with retention time 9.25 minutes was citronellal 32.106 % contain, peak Separated of the citral and forming geraniol with retention time 10.45 minutes was The mixture of citronellal and citral 1.5 citronellal with 6.66 % contain, and peak with gr was diluted in the solution of bisulfite retention time 11.01 minutes was geraniol with concentrate (4 M) and was added in the 27.37 % contain. beaker glass than stirred until appearing precipitate. This precipitate was soaked in the Isolation of Rhodinol from the trade cool ethanol. This precipitate was filtered with citronella oil whatman filter paper no 4. It will be obtained The trade citronella oil that contained the precipitate and filtrate. Than the precipitate much rhodinol was fractional distillated at was washes twice with diethyl ether. The reduce preasure yielded three fractions of precipitate that obtained was dilute in the distillate. As follow the chromatogram of sodium carbonate, Na CO 1M, then it was 2 3 distillate fraction III. added in the separatory funnel. The upper layer, organic layer was taken. This layer was washes with water until netral. Then that layer

484 Zaina Mukhia Bintan, et al Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada The 2nd International Conference on Chemical Sciences Proceeding ISSN NO. 1410-8313 Yogyakarta, October 14-16th, 2010

chromium oxide with 20.15 ml (0.25 mole) pyridine. The yield of synthesis indicated: pyridinium chromate was compound that crystal from colored orange and rendement 67.0 %. From IR spectrum (Figure 5) was indicated there is the sharp absorption at 3423.4 cm-1 indicated there is –NH group, the absorption at 3066 cm-1 there is =C-H stretching strengthen by the absorption at -1 1610.5 cm there is –C6H5, aromatic ring. Characteristic there is chromate ion (Corey and Schmidt, 1979) was indicated with there is -1 Figure 3. Chromatogram of the distillate fraction III the peak in 930, 875, 765 and 760 cm .

From the chromatogram above can look at the peak retention time 8.51 minutes contain 0.98% citronellal, peak retention time 9.67 minutes contain 34.95% citronellol and peak retention time 10.20 minutes contain 55,61% geraniol. Thus the distillate fraction II contained 90.56% rhodinol. From IR spectrum (Figure 4) can look at there are sharp absorption at 330.8 cm-1 indicated there is –OH group and strengthened by absorption at 1056.9 cm-1 that indicated there is C-O group (alcohol). The absorption at 2925.8 cm-1 there is CH stretching and strengthened by there are the absorption at Figure 5. IR spectrum of pyridinium chromate -1 -1 (PDC) 1448.4 cm and 1377 cm there are –CH3 group and –CH2- group. The absorption at 1670.2 cm-1 indicated there is the double bond The synthesis of citral from rhodinol C=C. The reaction between geraniol from rhodinol with pyridium chromate oxidator yielded citral. As follow the GC-MS chromatogram from the yield of oxidation.

Figure 4. IR spectrum of distillate fraction III

Synthesis of pyridinium chromate (PDC) Figure 6. The GC-MS chromatogram from the yield The pyridinium chromate oxidator had of rhodinol oxidation not prepared yet in the laboratory, so that we need to conduct synthezing pyridinium chromate with reacted 25 g (0.25 mole)

Zaina Mukhia Bintan, et al 485 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada ISSN NO. 1410-8313 The 2nd International Conference on Chemical Sciences Proceeding Yogyakarta, October 14-16th, 2010

Figure 7. MS spectrum of citral

Figure 8. MS spectrum of citronellol

The mixture of citral and citronellol were separated by reaction method of citral with NaHSO3 become citral bisulfite that dissolve in the water. The chromatogram of citral that separated from citronellol is presented in Figure 10.

Figure 9. IR spectrum of the yielded of rhodinol oxidation

From IR spectrum (Figure 9) was looked at the absorption of the mixture of citral Figure 11. IR spectrum of citral that yield of and citronellol. For citral was looked at that separation there is the absorption at 1734.5 cm-1, there was C=O group (carbonyl) and citronellol there -1 From IR spectrum above was looked at was the absorption at 3417.6 cm broad there -1 is –OH group (hydroxide group). being the absorption at 1734.5 cm indicated the carbonyl group, C=O, the absorption at 1639.4 cm-1 indicated to be double bond, The separation of citral and the forming of -1 -1 geraniol absorption of C=C at 1450 cm and 1370 cm to be –CH3 group and –CH2- group.

Figure 10. The chromatogram of citral that has Figure 12. The chromatogram of the yield of citral been separated reaction with NaBH4

486 Zaina Mukhia Bintan, et al Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada The 2nd International Conference on Chemical Sciences Proceeding ISSN NO. 1410-8313 Yogyakarta, October 14-16th, 2010

In the future citral was reacted by CONCLUSION NaBH4 become geraniol again. the chromatogram of the yield of citral reaction From the result of research and the with NaBH4 is shown in Figure 12. discussion, can be concluded as follows: From the chromatogram above was 1. The trade citronella oil that used in this looked at being the height peak, that is research, citronellol contents 32.10 %, geraniol with 47.0% content. As follows, IR citronellal content 6.60 % and geraniol spectrum of the yield of citral reaction with content 27.37 %. NaBH4. 2. Rhodinol was the yield of the fractional re- distillate, that was fraction distillate with citronellol contents 34.95 % and geraniol contents 55.61 %. 3. Geraniol that obtained from the separation with this method had 47 % purity.

REFERENCES

1. Corey, E.J. dan G. Schmidth, 1979, Useful Procedure for the Oxidation of Alcohol Involving Pyridinium Dichromate in Aprotic Media, Tetrahedron Letters, No. 5, 399-402. 2. Corey, S.J. dan J.W. Suggs, 1975, Figure 13. IR spectrum of the yield of citral reaction with NaBH Pyridinium Chlorochromate and 4 Efficient Reagent for Oxidation of Primary and Secondary Alcohol to From IR spectrum (Figure 13) were look at Carbonyl Compounds, Tetrhedron being the absorption at 3487.1 cm-1 indicated – Letters, No. 5, 399-402. OH group, strengthened by 1022 cm-1 and 1045 3. Devakumar, C., M.R. Narayan, and M.N. cm-1 to be C-O group (alcohol), the absorption Akhan, 1977, Synthetic Product from Oil at 3977.9 cm-1 indicated C-H stretching, of Citronella, Indian Perfumer, XXI, 3, 139- strengthened by the peak at 1445.4 and 1380 145. -1 4. Furniss, B.S., A.J. Hannaford, and P.W.G. cm indicated –CH3 and –CH2- group and the absorption at 1639.4 cm-1 indicated C=C group Smith, 1989, Vogel’s Textbooks of (double bond). Thus component was real Practical Organic Chemistry, fifth edition, geraniol. Longman Scientific and Technical, New York 5. Guenther E., 1950, The Essential Oils, Volume 4, D. Van Nostrand Company Inc., New York. 6. Solomon, T.W.G., 1990, Fundamental of Organic Chemistry, Third Edition, John Wiley and Sons, New York.

Zaina Mukhia Bintan, et al 487 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada