SU362020A1 - METHOD OF OBTAINING 1,7-BIS- (HYDROXIDIMETHILSILYL) -CARBORANE - Google Patents

Description

one

The invention relates to a process for the preparation of 1,7-bis - (hydroxymethylsilyl) - carboran, which can be used as a monomer for the synthesis of carboransiloxane polymers.

A known method for the synthesis of 1,7-bis- (hydroxydimethylsilyl) -carborane by hydrolysis of 1,7-bis (chloromethylsilyl) -carborane with an excess of water in an acetone solution.

The disadvantage of this method is the use of 1.7-bis- (chloro-organosilyl) -carborane as the starting compound, the preparation and purification of which are associated with considerable difficulties and losses, which leads to an increase in the cost of the target product.

CH}

CH5

H-Si-C-B Н H, O-C-S. - Н + НгО-НО - В, оН, о - С-S. - ОН - 2Н, iiI

СНзCHjСНзCHj

in a boiling mixture of concentrated hydrochloric acid and alcohol (for example, methyl, ethyl or propyl) for 15 hours.

The resulting 1,7-bis- (hydroxymethylsilyl) -carborane is recrystallized from a 7-10% solution in hexane or heptane and the desired product of high purity is obtained with a yield of 74-75%. Residue after

Reducing the loss of 1,7-bis- (chloridorganosilyl) -carborane due to less thorough purification results in an insufficiently pure 1.7-bis- (hydroxydiorganosilyl) -carborane, which is unsuitable for the synthesis of high molecular weight polymers.

In order to eliminate the above disadvantages, it is proposed to use 1,7-bis- (dimethylsilyl) -carborane as the starting compound and to carry out the process in an acidic medium. Hydrolysis is best carried out in a boiling mixture of alcohol and hydrochloric acid.

The essence of the proposed method lies in the fact that the 1.7-bis- (dimethylsilyl) -carborane hydrolysis is carried out according to the scheme:

CH-,

C (s)

distilling off the solvent is treated similarly to the original 1,7-bis- (dimethylsilyl) -carborane and additionally isolates the desired product in a yield of 20-25%.

Thus, the proposed method produces a product of high purity with a yield of more than 90%.

Example 1. A flask of 100 ml volume, equipped with a stirrer and reflux condenser for hydrogen, was charged with 5 g of 1.7-bis- (dimethylsilyl) -carborane, 50 ml of ethyl alcohol and 20 ml of concentrated HC1. The reaction mixture is boiled under stirring for 15 hours, with hydrogen gas evolving (925 ml, reduced to normal conditions). After distilling off the alcohol, water and hydrochloric acid, 50 ml of hexane is poured into the flask and the reaction mass is boiled until the reaction products are completely dissolved. After 2-3 hours, a precipitate is precipitated from the solution, it is filtered and dried, and 4.2 g (75%) of bis- (hydroxymethylsilyl) -neocarborane are obtained. The residue after distilling off the solvent (1.4 g) is treated in the same way as the original 1,7-bis- (dimethylsilyl) -carborane, and 1.05 g (75%) of b “c- (hydroxymethylsilyl) -neocarborane are obtained. Only 6.25 g (93.5%), so pl. 99 ± 0, HS.

Found%: OH 11.43. Calculated,%: OH 11.62.

Example 2. The reaction is carried out in the same manner as described in Example 1, only

methyl alcohol is used instead of ethyl alcohol. 2.65 g (44.1% yield) of 1.7-bis- (dimethylhydroxysilyl) -carborane are obtained.

Example 3. The reaction is carried out in the same manner as described in Example 1, except that propyl alcohol is used instead of ethyl alcohol. 3.61 g (64.5%) of 1,7-bis (dimethylhydroxysilyl) -carborane are obtained.

Subject invention

Claims (2)

1. A method for producing 1.7-bis- (hydroxydimethylsilyl) -carborane by hydrolysis of a bifunctional creamy carboran derivative, characterized in that, in order to simplify the process, 1.7-bis (dimethylsilyl) -carborane and the process is conducted in an acidic environment. 2. A method according to claim 1, characterized in that the hydrolysis is carried out in hydrochloric acid and alcohol at the boiling point of the reaction sm-thou.