SU1553530A1 - Method of producing pyridine-2-carboxamide - Google Patents

Abstract

The invention relates to heterocyclic substances, in particular the preparation of pyridine-2-carboxamide, a plant growth regulator used in agriculture. The goal is to increase productivity and simplify the process. The latter is carried out by hydrolysis of 2-cyanopyridine in the presence of NAOH and water at a molar ratio of 1: 0.03 - 0.2: 4 - 10 (preferably 1: 0.05 - 0.15: 5 - 10) and 100 - 130 ° С within 5 - 20 min. These conditions allow to obtain the target product with a yield of up to 100% and a capacity of 1.2-9.0 kg / l of water ^. h, which is 600 - 900 times higher than in the famous case. 1 hp f-ly.

Description

The invention relates to an improved method for the preparation of pyridine-2-carboxamide, which is used as a plant growth regulator.

The aim of the invention is to simplify the process, increase its productivity and increase the yield of the target product due to hydrolysis of 2-cyanopyridine with aqueous alkali at a molar ratio of nitrile: caustic soda: water, equal to 1: (0.03-0.2) :( 4 -10) and temperature SW 130 ° C for 5-20 minutes.

Example 1. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of caustic soda and 1.04 g (0.0577 mol) of water (molar ratio nitrile: alkali: water 1: 0.05: 6) is placed in a stainless steel autoclave and heated at 120 ° C for 10 minutes. According to a polarographic analysis, the hydrolyzate contains 1.1730 g (0.0096 mol) pyridine-2-carboxamide (picolnnamide). Yield 100% based on taken nitrile.

The resulting solid precipitate is filtered, washed with water. Received 1,085 g (0,0088 mol). M.p. 105 ° -107 ° C. The yield of the selected picolinamide was 92.5% of the theory to the initial 2-cyanpyridine. Process productivity 6.8 kg / l NaOh

g.

Example 2. The method is carried out as described in Example 1. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 0.87 g (0.0480 mol) of water (molar ratio nitrile: caustic soda: water 1: 0.05: 5) is heated for 9 minutes at 120 ° C. 1.1707 g (0.0092 mol) of picolinamide are obtained, yield

(AU.

99.8%. Process productivity 9.0 kg / l Н20-Чс

Example 3. The method is carried out according to Example 1. 1 g (0.0096 mol) of 2-cyanopyridine „0.01115 g (0.00028 mol) of sodium hydroxide, 1.04 g (0.0577 mol) of water (molar ratio nitrile: caustic soda: water 1: 0.03: 6.0) is heated for 10 minutes at 120 ° C. 0.9023 g (0.0074 mol) of picolinamide is obtained, yield 80.0%. Process productivity 5.4 kg / l

Example 4. The method is carried out as described in Example 1. 2 g (0.0122 mol) of 2-cyanopyridine O, 076 g (0.00192 mol) of sodium hydroxide, 2.08 g (0.1154 mol) of water (molar ratio caustic nitrile: water 1: 0.1: 6.0) is heated for 10 minutes at 120 ° C. Get .. 2,3156 g (0,01898 mol) picolinamide, yield 98.7%. The productivity of the process is 6.7 kg / l.

Example 5. The method is carried out according to Example 1. 1 g (0.0096 mol) of 2-cyanopyridine O, 0577 g (0.00144 mol) of sodium hydroxide, 1.04 g (0.0577 mol) of water (molar ratio nitrile: caustic soda: water 1: 0.15: 6.0) is heated for 10 minutes at 120 ° C. Get 1,0416 g (0,0085 mol) of picolinamide yield 88,8%, the performance of the process of 6.0 kg / L.

Example 6. The method is carried out as described in Example 2. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0769 g (0.00192 mol) of caustic soda, 1.04 g (0.00577 mol) of water (molar ratio nitrile: alkaline lead 1: 0.2: 6.0) is heated for 10 minutes at 120 ° C. 0.9126 g (0.0075 mol) of picolinamide is obtained, yield 77.8%. Process productivity 3.0 kg / l NgO-h „

Example 7. The method is carried out as described in Example 1. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 0.070 g (0.038 mol) of water (molar ratio nitrile: alkali: water 1: 0.05: 4) is heated for 10 minutes at 120 ° C. 0.9701 g (0.0079 mol) of picolinamide is obtained, yield 82.7%. Process performance 8.4 kg / l.

Example 8 The method is carried out as in Example 1-1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 1.4 g (0.0769 mol) of water (molar ratio: nitrile alkali: water 1: 0.05: 8) heat

10 min at 120 ° C. 1.1730 g (0.0096 mol) of picolinamide are obtained, yield 100%. Process productivity 5.1 kg / l.

Example 9. The method is carried out as described in Example 1. 1 g (0.0096 mol) of 2-α-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 1.73 g (0.0961 mol) of water (molar the ratio of nitrile; e-night: water 1: 0.05: 10) is heated for 10 minutes at 120 ° C. 1.1707 g (0.0096 mol) of picolinamide are obtained, yield 99.8%. Process productivity 4.1 kg / l NgO-h.

Example 10. The method is carried out as described in Example 1. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 1.04 g (0.0577 mol) of water (molar ratio nitrile: alkali: water 1: 0.05: 6) is heated for 5 minutes at 120 ° C. “1.0065 g (0.0082 mol) of picolinamide is obtained, yield 85.8%. Productivity is 1,2 kg / l Ngr-h.

Example 11, The method is carried out as described in Example 1. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 1.04 g (0.0577 mol) of water (molar ratio nitrile alkali: water is 1: 0.05: 6) is heated for 15 minutes at 120 ° C. 1.1730 g (0.0096 mol) of picolinamide are obtained, yield 100%. Process productivity 4.5 kg / l NgOh,

Example 12. The method is carried out according to Example 1. 1 g (0.0096 mol) of 2-β-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 1.04 g (0.0577 mol) of water (molar the ratio of nitrile alkali: water 1: 0.05: 6) is heated for 20 minutes at 1200 ° C. “1.1730 g (0.0096 mol) of picolinamide is obtained, yield 100%. Process productivity 3.4 kg / l.

Example 13. The method is carried out as described in Example 1. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 1.04 g (0.0577 mol) of water (molar ratio nitrile: caustic soda: water 1: 0.05: 5) is heated for 10 minutes at 110 ° C. 1.1038 g (0.0090 mol) of picolinamide is obtained, yield 94.1%. Process productivity 694 kg / l HgO-h.

Example 14, The method is carried out as described in Example 1. 1 g (0.0096 mol) of 2-cyanopyridine, 0.0192 g (0.00048 mol) of sodium hydroxide, 1.04 g (0.0577 mol)

Water (molar ratio of nitrile alkali: water 1: 0.05: 6) is heated for 10 minutes at 130 ° C. 1.1672 g (0.0095 mol) of picolinamide are obtained, yield 99.5%. Process productivity 6.7 kg / l HjO-h.

Claims (2)

1. The method of producing pyridine-2-carboxamide by hydrolysis of 2-cyanopy1 e1553530 Ridines with an aqueous solution of alkali, heating, characterized in that, in order to simplify the process and increase its productivity, hydrolysis is carried out in a steel autoclave at a molar ratio of nitrile:: caustic soda: water, equal to 1: (0.03-0.2 ): (4-10) and a temperature of 100-130 ° C for 5-20 minutes. 2. The method according to claim 1, characterized in that, in order to increase the yield of the target product, the process is carried out at a molar ratio of reactants equal to 1: (0.05-0.15): (5-10) per for 10-20 minutes