SU137503A1 - Method for producing 3-methoxy-4-benzyloxybenzyl cyanide - Google Patents

Description

A known method for producing 3-methoxy-4-benzyloxybenzyl cyanide from 3-methoxy-4-benzyloxybenzyl chloride and sodium cyanide in a hydroalcoholic medium. In this case, it is necessary to use 9–10-fold excess (from theoretical) sodium cyanide, since with a decrease in its amount, the yield of nitrile decreases, due to the formation of 3-methoxy4-benzyloxybenzyl ethyl ether, which is a by-product of the reaction.

The proposed method for producing 3-methoxy-4-benzyloxybenzyl cyanide is based on the reaction of reacting 3-methoxy-4-benzyloxy-benzyl chloride with sodium cyanide, taken with an excess corresponding to 40% of the theoretical in water-dioxane medium at 60 °. Due to the fact that the reaction proceeds rapidly under these conditions, it is possible to avoid the polymerization of the nitrile due to the influence of the sodium carbonate impurity present in the technical sodium cyanide.

Thus, the proposed method allows drastically reducing the consumption of sodium cyanide, while maintaining a satisfactory yield of the final product.

Example. To a solution containing 15 g of 86% sodium cyanide, 100 ml of water and 50 ml of dioxane at a temperature of 55-60 °, 50 g of crystalline 3-methoxy-4-benzyloxybenzyl chloride are added over 30 minutes and the reaction mixture is stirred at this temperature for two hours. Then the reaction mass is treated in a separating funnel with 500 ml of water and 200 ml of chloroform. After delamination, the lower layer is separated, washed with water, dried with magnesium sulfate, and the chloroform is removed in vacuo. The remaining brown oil is dissolved in 80 ml of ethanol (rectified), seeded and left in the refrigerator overnight. The precipitation is filtered off and after washing with alcohol, 25.5 g of 3-methoxy-4-benzyloxybenzyl cyanide are obtained.

No. 137503-2 -

The mother liquor is evaporated under vacuum in a water bath, and the remaining oil is distilled at 1 mm, collecting the fraction boiling at 195-205 °. This fraction was dissolved in twice the amount of ethanol, left to crystallize in the refrigerator, and another 5 g of the nitrile was obtained. The total yield of Z-methoxy-4-benzyloxybenzyl cyanide is 30.5 g (63.3% of the theoretical), so pl. 67-68 ° (from alcohol).

Subject invention

The method of producing 3-methoxy-4-benzyloxybenzyl cyanide by reacting 3-methoxy-4-benzyloxybenzyl chloride with an excess of sodium cyanide, characterized in that, in order to reduce the consumption of cyanide sodium, reduce the duration of the synthesis and reduce the amount of by-products, the reaction is carried out in water-dioxane mixes.