SU572490A1 - Method of separating carvone - Google Patents

Description

(54) METHOD FOR EXTRACTING CLRVON

This invention relates to a technique for isolating carvone essential oils for perfuming chewing gum, pharmaceuticals and oral care products.

There are several known methods for isolating carvoia from caraway and dill oil and caramel oil. The most common of these is the method of separation with sodium sulfite in a neutral medium. Carvone reacts with 2 moles of sodium sulfite to form the dihydrosulfonic acid salt of the composition

CioHieOrSaNaa,

which requires 2 moles of caustic and sodium 1 for decomposition.

The closest to the proposed method is the method of carvoia isolation, which consists in adding 1.9 mol of saturated sodium sulfite solution to 200 g of dill essential oil containing 0.59 mol of carvone for 5 hours at 95-97 ° C. and neutralizing the reaction mass as the sodium hydroxide releases 58 ml of 50% acetic acid (0.48 mol). The unreacted oil is extracted with 500 ml of petroleum ether. The aqueous solution of the carvone derivative is decomposed by the addition of 680 ml of 30% sodium hydroxide (5.1 mol) and the carvone is extracted with 300 ml of leftolether. The yield of carvoia is 64.9% by weight in terms of oil contained in the oil. Loss of oil 4,2% 2.

However, by this method the target product

is obtained with a low and unstable yield (64.9 wt.%); for its implementation

high raw material consumption is required; process

proceeds in several stages within 5 hours

According to the proposed method, the extraction is carried out for 1 -1.5 h 0.76-1.0 mol

a saturated solution of sodium sulfite, the iced solution is neutralized with 0.35-0.5 mol of sulfuric acid and the resulting carvoia derivative 0.55-1.0 mol of sodium hydroxide.

Thus, according to the proposed method, the essential oil containing carvone interacts with a saturated solution of sodium sulfite and the liberated alkali is simultaneously neutralized with an inorganic acid.

The unreacted oil is separated by decay; The production is decomposed by a conventional method and the carvoi are separated by decantation. The yield of the guarded carvone is 84.6 wt. % Due to the use of this method, the yield of carvone is increased, the consumption of sodium sulfite is reduced by 3-4 times and the consumption of caustic soda is reduced by 5-7 times, the interaction time is reduced to 1-1.5 hours, the organic acid to neutralize the reaction

mass is replaced by inorganic. The amount of sodium sulfite per mole of carvone has been reduced from 3.2 mol to 0.76-1 mol compared to the known method, which avoids the formation of a compound of 2 moles of sodium sulfite, from which the carvone is not fully regenerated by alkali. The amount of caustic soda to decompose the carvone derivative is reduced from 5.1 mol to 0.76-1 mol per I mol of carvone contained in the essential oil. The use of an inorganic acid as a neutralizing agent makes it possible to reduce the solubility of the essential oil and carvone, to stabilize the process by eliminating the extraction stage of unreacted oil and carvone.

Example. 18.7 kg (0.068 mol) of sodium sulfite pentahydrate in the form of a saturated aqueous solution and 39 kg of dill oil (0.078 mol carvone) and for 1.5 hours during transfer and temperature 95- 96 ° C. The reaction mass is neutralized with 27% sulfuric acid (0.038 mol); after cooling to 15–20 ° C, the lower layer is drained (an aqueous solution of the monohydrosulfone derivative, the bromine number found is 123.8, the theoretical is 125.5) and then the top is 29 kg of unreacted oil (0.007 mole of carvone). The monohydrosulfone derivative in the same apparatus is treated with 32-35% sodium hydroxide solution (0.056 mol) at a temperature of 40-45 ° C for 0.5 h. After cooling, the upper layer is drained. The output of technical carvone is 10.8 kg (91 wt.%). Technical carvone is distilled under vacuum and perfume carvone is obtained; yield 9.9 kg. The properties of the carvone obtained are the following: density at 20720 ° С-0.955-0.960 g / cm,

P2d ° 1,4960-1,4990, t. Kip. / b mm RT. Art. 86-

88 ° C, the angle of rotation of the polarization plane at 20 ° C from +50 to +65 degrees, the content of ketones (oxylation), not less than 98%, IR spectrum 3088, 3020, 2831, 1680, 1380, 1365, 895, 700 cm one.

Claims (2)

1.E. Gunther.The essential oils, 1949, II, 412. 2.V. P. Nigam et al., “Studies on the isolation of carvone from dill oil. J. Institution of Chemitsts (India) 1967, 39, No. 3, 141.