T R A N S F O R M A T I O N S OF F U R Y L - A N D T E T R A H Y D R O F U R Y L -

3 - A L K A N O L S ON A C T I V E C A R B O N

(UDC 542.97 + 547.721)

N. I . S h u i k i n , R. A. K a r a k h a n o v , V. G. G l u k h o v t s e v , a n d I . I . I b r a k h i m o v

N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR Translated from Izvest iya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 182-184, January, 1966 Original ar t icle submitted June 2, 1965

The catalytic proper t ies of active carbon have long a t t racted the attention of invest igators . At the present t ime a whole ser ies of papers and patents exists in the l i te ra ture , devoted to a study of the various react ions: dehydration, dehydrogenation, and dehalogenation, taking place on active charcoals (AC) [1-4].

The present paper is devoted to a study of the catalytic t ransformat ions of some fury l - and te t rahy- drofurylalkanols in the vapor phase on b i rch active charcoal (BAC).

In studying the dehydrogenation of ethyl alcohol on various carbon samples it was shown by Lemoine [5] that on BAC the alcohol is dehydrogenated to acetaldehyde even at 450 ~ A patent also exists in the l i te ra ture where the authors descr ibed a method for the preparat ion of acetone by the dehydrogenation of isopropyl alcohol on AC at 400-700 ~ [6], but in all probability, together with the dehydrogenation of the alcohol, the la t ter is also dehydrated to the olefin at this tempera ture , which great ly reduces the yield of the ketone.

In studying the t ransformat ion of the furan and te t rahydrofuran alcohols on active birch charcoal we found that these alcohols are dehydrogenated to the corresponding ketones at the comparat ively low tem- pera tures of 350-380~

L 4 B a c I ~0 ~ ~ [ ~~176176 \0 / I!

OH 0

where R = ~ - fu ry l - and ~- te t rahydrofuryla lkyls .

At a higher temperature , of the order of 400-450 ~ the s tar t ing alcohols undergo dehydration, which goes nonselectively and leads to the formation of a mixture of fu ry l - and te t rahydrofurylalkenes. We also ran some experiments using asbiree carbon, obtained f rom glucose. The experimental data obtained here unequivocally indicate that only the carbons with a highly developed surface (500-700 m2/g) and charac - ter ized by having a cer ta in ash content, exhibit catalytic activity, whereas the ashfree carbons, the su r - face a rea of which does not exceed 5-10 m2/g, do not exhibit catalytic activity. In order to obtain com- parat ive data on the activity of various catalysts for the dehydrogenation of furan alcohols we ran some experiments on the dehydrogenation of 1-furyl-3-butanol on 5% palladized birch charcoal . As was to be expected, the dehydrogenation rate of the furan alcohol on this catalyst proved to be considerably higher than on BAC. Thus, even at 300 ~ and a space velocity of 0.2 h -i , we obtained the corresponding ketone f rom 1-furyl-3-butanol in a yield exceeding 60%. It should be mentioned that the synthesis of furan, and especially of te t rahydrofuran ketones, is very complex and is accomplished by the selective hydrogenation of furfurylidene ketones over Pd-A1 catalyst [7].

E X P E R I M E N T A L

The start ing 1- (~- fury l ) - and 1- (~- te t rahydrofury l ) -3-a lkanols were synthesized as described in [8]. As catalyst we took birch active charcoal with a granule size of 2-3 mm and a specific surface a rea

168

TABLE I .

Starting compound

1- (~-Furyl)-3-butanol I- (~-Furyl)-3-butanol I- (~-Furyl)-3-butanol

Results of the Dehydrogenation of l-(~-Furyl)- and l-Tetrahydrofuryl-3-alkanols

1- (a -Fury l ) -3-butanol 1,5-Di- (a- furyl ) -3-pentanol 1 ,5-Di- (a - fury l ) -3-pentanol 1- (a -Te t rahydrofury l ) - 3-butanol 1 - ( ~- Tet rahydrofuryI ) - 3-butanol

Catalyst

BAC BAC BAC

PdC BAC Pd--C BAC BAC

Temp.,

35O 380 450

310 380 310 350 370

~ Obtained compounds

I- (c~-Furyl)-3-butanone I- (~-Furyl)-3-butanone I- (~-Furyl)-3-butanone I- (c~-Furyl)-2-butene i- (~-Furyl)-3-butanone i, 5-Di- (c~-furyl) - 3-pentano ne 1,5-Di-(~-furyl)-3-pentanone l-(c~T etrahydrofuryl)- 3-butanone 1-{~-T etrahydr ofuryl)-3-butanone

Yield, %

35 52 14 17 61 48 65 28 50

TABLE 2. Properties of Furan and Tetrahydrofuran Alcohols and Ketones

Furyl- and tetrahydrofurylalkanols and B.p., ~ alkanones (p, mm of Hg) n~ d 20

i - (a-Furyl)- 3-butanol I- (~-Furyl)-3-butanone I- (~-Tetrahydrofuryl) - 3-butanol i- (~-Tetrahydrofuryl)-3-butanone 1,5-Di- (c~, cd-furyl)-3-pentanol 1,5-Di- (~, c~' -furyl)- 3-pentanone

70 - 71(6) 82.5- 83(8)

104 -105(10) 86 - 88(10)

125 -126~5) 136 -137(4)

1.4752 1.4704 1.4562 1.4485 1.5042 1.5021

1.0214 1.0356 0.9770 0.9863 1.1061 1.1002

of 630 m2/g. The charcoal was previously treated with boiling 15% hydrochloric acid solution, and then washed in succession with distilled water, 5% NaOH solution, and again with water. The ashfree carbon with a specific surface area of 1 m2/g was obtained by the ignition of glucose at 800 ~ The starting alco- hols were passed over the catalyst at a space velocity of 0.2 h -I and at the temperatures indicated in Table I. After drying, the obtained catalyzates were fractionally distilled through an efficient colamn (30 theoretical plates), and also analyzed by gas-liquid chromatography. The standard furan and tetrahy- drofuran ketones were obtained by the hydrogenation of the corresponding furfurylidene ketones in an autoclave on skeletal Cu-Al and Pd-Al catalysts [7,9],

An SKB IOKh AN SSSR chromatograph was used for the analyses, with the detection based on the heat conductivity: as the stationary liquid phase we used silicone elastomer (10%), deposited on sodium chloride, and helium as the carrier gas. The column length was 3 meters, and the internal diameter was 6 ram. The column temperature was 110% The results of the experiments are given in Table 1. The properties of the starting alcohols, and also of the obtained ketones, are given in Table 2.

CONCLUSIONS

!. A study was made of the catalytic transformations of some furyl- and tetrahydrofuryl-3-alkanols on birch active charcoal. At 350-380 ~ these alcohols undergo dehydrogenation to the corresponding ketones in a yield exceeding 50%.

2. Ashfree carbon does not exhibit catalytic activity under comparable conditions.

3. Palladized charcoal (5% Pd) leads to the dehydrogenation of the furylalkanols to the corresponding ketones at 300 ~ in 60% yield.

LITERATURE CITED

I. T. Bahr, Berlin, 64, 2258 (1931); A. A. Balandin, G. I. Levi and E. A. Broude, Izv. AN SSSR, Otd. Khim. Nauk, 1960, 614.

2. B. L~ Moldavskii, F. Besprozvannaya, G. D. Kamusher and M. V. Kobyl'skaya, Zh. Obsheh. Khimii, 7, 1840 (1937).

3. N.I. Shuikin and T. I. Naryshkina, Dokl. AN SSSR, 13____5, 105 (1960); 136, 849 (1961). 4. P.G. Ivanov, Uch. Zap. MGU, 7_!1, 226 (1941). 5. G. Lemoine, Compt. Rend., 144, 357 (1907).

169

6o

7.

8o

9.

E. M. MeMahon and J . S. Kimble , U. S. Patent 2087038 (1937); C. A., 31 , 62539 (1937). N. I. Shuikin~ I. F. Beltski i , V. M. Shostakovskii and R. A. Karakhanov, Dokl. AN SSSR, 151, 1350 (1963). I. F. BelVskii and R. A. Karakhanov, Izv. AN SSSR, Ser. Khim. , 1963, 905. I. F. BelVskii, N. I. Shuikin and V. M. Shostakovskii , Izv. AN SSSR, Otd. Khim. Nauk, 1962, 1821.

All a b b r e v i a t i o n s of p e r i o d i c a l s in the a b o v e b i b l i o g r a p h y are l e t t e r - b y - l e t t e r t r a n s l i t e r a - t i ons of the a b b r e v i a t i o n s as g i v e n in the o r i g i n a l R u s s i a n jou rna l . Some or all o f th is peri- odical l i tera ture r.,lay w e l l be ava i lab l e in E n g l i s h translat ion. A c o m p l e t e l i s t of the cove r - to - c o v e r E n g l i s h t r a n s l a t i o n s a p p e a r s a t the b a c k of t h i s i s s u e ,

170