SU549964A1 - Method of producing recemic biotin - Google Patents

Description

(St) METHOD FOR OBTAINING RACEECH BIOTIN

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The invention relates to a method for producing a racemic biotin of the formula

ABOUT

II

HS BK

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used as a biostimulant of microbiological processes.

The lj method of producing biotin by the reduction of 2,3, ..., 5 tetra dehydrobiotin with trialkylsilane to trifluoroacetic acid is known. J5

Also known is 2 a method for producing racemic biotin by the catalytic hydrogenation of 2,3,., 5-tetrahydrobiotin esters over molybdenum trisulfide and alumina in an autoclave under pressure at 200-2 U-C, followed by saponification of the biotin intermediate esters.

However, the known methods are complex and do not allow to obtain the desired product in high yield. Within 120 h at the output reaches g 10.

The purpose of the invention is to eliminate these disadvantages.

This is achieved by the fact that the hydrogenation of esters 2,3 | 5-tetradehydrobiotin is carried out with trialkylsilane in trifluoroacetic acid in the presence of boron trifluoride etherate, preferably at lO-SO C.

Claims (2)

The process proceeds according to the scheme. The starting product under these conditions is not subjected to hydrogenation. The reaction time is 50 hours, the yield of biotin is 0. Example 1. About 3 ml of trifluoroacetic acid are added O, 3 ml of boron trifluoride etherate, O, 6 g of methyl ester 2, 3, 5 tetradehydrobiotin and 2 ml of triethylsilane, heated for 25 hours at 50 ° C evaporated in vacuum, the residue is mixed with a solution of 2 ml of concentrated hydrochloric acid in 10 l of alcohol, kept at 20 ° C for 12 hours, evaporated in vacuum, a solution of 1 g of potassium hydroxide in 10 is added to the residue ( left for 12 hours at 20 ° C, the alcohol is distilled off in vacuo, the residue is dissolved in 5 ml of water, filtered, the filtrate is acidified and diluted hydrochloric acid (1: 1) to pH 2, the precipitate is filtered off, washed with water and acetone, recrystallized from water with the addition of activated charcoal, and 0.22 g (0%) of racemic biotin is obtained, mp. ,, 53 (TLC, ethyl acetate-alcohol, 3: 2, appearance in iodine vapors.) The resulting biotin does not depress the melting point in a mixed sample with a known sample and has the same R and IR spectrum. Example 2.Kb ml of triorylloacetic acid was added with 0.3 ml of boron trifluoride etherate, O, 6 P 2,3,, 5-tetradehydrobiotin ethyl ether and ml of methyl dipropylsilane, heated for 25 hours at, treated as in Example 1, and 0 is obtained 21 g (3b) of racemic biotin, TopPLo 22b-227 C, Claim 1. The method of producing racemic biotin of the formula by hydrogenating the 2,3,, 5 tetradehydrobiotin ether with heating followed by saponification of the resulting biotin ether, characterized in that yield of the target product and simplify the process technology , the hydrogenation of 2,3-j5 tetradehyde-biotin ether is carried out with trialkylsilane in trifluoroacetic acid in the presence of boron trifluoride etherate, 2 °. The method according to claim 1, in which hydrogenation is carried out at 40-50 ° C. Sources information taken into account during the examination 1. USSR author's certificate No. i 27901, 30,12.71. 2, US Patent M, 260-3097, 0 oO5050