SU1288183A1 - Method of producing isonicotinic acid - Google Patents

Abstract

The invention concerns heterocyclic carbopic acids, in particular IZOSH1-COTINOVOH acid (IC), which is used in the synthesis of plant growth stimulants and anti-TB drugs. An increase in the productivity of the process and a decrease in the amount of wastewater reach- ing, with other conditions of 4-niaH-pyridip hydrolines (CP). The process is carried out in the presence of alkali (NaOH) at 50 - 30 C and a molar ratio of UTItNaOHiHgO 1: (1, 5 - 1.75): 10 - 17 for 9-10 minutes. IR is separated from the reaction mixture by acidification of the reaction mixture to a pH of 3.2 and the IR precipitate is separated. The yield is 99.2%, the productivity is 2.7 kg / l. The amount of wastewater decreases due to the production of a more concentrated IR solution. Table I and a yue 00 Cs3 „

Description

The invention relates to an improved method for producing isonicotinic acid, which is used in the synthesis of anti-tuberculosis drugs and plant growth stimulants.

The purpose of the invention is to increase the productivity of the process by reducing the amount of waste water due to hydrolysis of 4 cychiridine with an aqueous solution of caustic soda at a molar ratio of A-cyanpyridine: caustic soda: water equal to ItU, 1.75) :( 10 - 17) within 9–10 min.

Example 1, 1.0 g of 4-cyanopyridine (0.0096 mol), 0.582 g (0.0144 mol) of caustic soda and 2.9 g (0.1635 mol) of water (molar ratio nitrile: caustic soda: water equals 1: 1.5: 17) is placed in a stainless steel autoclave and heated for 10 minutes in an electric furnace at 50 ° C. According to a polygraphic analysis, the hydrolyzate is content of ION767 g (0.0095 mol) of isonicotinic acid. The yield of the target product is 99.5%,

The reaction mixture was acidified with concentrated hydrochloric acid to pI 3.2. In this case, isonicotinic acid precipitates. 1.1614 g (0.0094 mol) of acid are obtained,. 317 ° С, neutralization coefficient 122.7, the yield of the isolated acid is 98.2% for the taken, the productivity is 2.4 kg / l,

Example 2 Analogue of Example 1 0.5 g (0.0048 mol) of 4-cyanopyrvdine, 0.317 g (0.0079 mol) of caustic soda and 1.5 g (0.0817 zero) of water (molar ratio nitrile: caustic soda: water is 1: 1.65: 17) heated for 9 minutes at 60 ° C, 0.5907 g (0.0048 mol) of isonitic acid is obtained, yield 99.9%, process productivity 2.7 kg / l 1 (

.-

N „0-h

Example 3, Analogously to Example 1, 2 g (0.0122 mol) of 4-cyanopyrion – 50 dyn, 1.154 g (0.0288 mol of caustic soda and 4.8 g (0.2692 mol) of water; molar ratio nitrile: caustic soda: water is 1: 1.5: 14 heated for 10 minutes at 80 ° C. 2.3630 g (0.0192 mol) of isonicotinic acid are obtained, yield 99.9%, process productivity, 2.9 kg / l PDO H ,

Example 4 (for comparison).

Analogously to example 1, 1 g (0.0096 mol of 4-cyanpirvdin, 0.385 g (0.0096 mol.) Of caustic soda and 2.9 g (0.1611 mol) of water (molar ratio of nitrile: caustic soda: water is 1: 1:17) heat up, heat for 10 minutes at 80 ° C, 0.9638 g (0.0078 mol) of isonicotinic acid are obtained, yield 81.5%, productivity 1.97 kp / l H O-h.

Example 5. Analogously to example 1, 2 g (0.0192 mol) of 4-cyanopyridine, 1.35 g (0.0336 mol) of caustic soda and 5.9 g (0.3269 mol) of water (molar ratio nitrile: caustic soda: water is 1: 1.75: 17) heated for 9 minutes at; 2.3630 g (0.0192 mol) is obtained — isonicotinic acid, yield 99.9%, productivity of the process is 2.67 kg / l.

Example 6 (for comparison). Example 1 I g (0.0096 mol) of 4-cyanopyridine, 0.769 g (0.0192 mol) of caustic soda and 2.9 g (0.163 mol) of water (molar ratio nitrile: caustic soda: water is 1: 2 : 17) heating; heat for 10 minutes at 80 ° C; 1.1708 g (0.0095 mol) of isonicotinic acid are obtained, yield 99.9%, process productivity 2.4 kg / l.

Example 7 Similarly to Example 1 0.5 g (0.0048 mol) of 4-cyanopyridine, 0.2884 g (0.0072 mol of caustic soda and 0.9 g (0.048 mol) and water (molar ratio nitrile : caustic soda: water is 1: 1.5: 10) heated for 10 minutes. To obtain 0.5907 g (0.0048 mol) of the desired product, yield 99.9%, the productivity of the process 4.1. kg / l K, 0 h.

Example 8 (for comparison). Analogously to example 1, 1 g (0.0096 mol) of 4-cyanopyridine, 0.577 g (0.0144 mol) of caustic soda and 1.0 g (0.0577 mol) of water (molar ratio nitrile: caustic soda: water is 1: 1.5: 6) heated at 80 ° C for 10 minutes. Get 1.0561 g (0,0085 mol) of the target acid, the output of 89.3%, the performance of the process of 6.1 kg / ln, 0 H

Example 9 (for comparison). As in Example 1, 0.5 g (0.0048 mol) of 4-cyanopyridine, 0.288 g (0.0072 mol) of caustic soda and 2.2 (O, 1202 mol) of water (molar ratio nitrile: caustic soda: water is 1 : 1.5: 25) heated for

10 min at 80 ° C ,, get 0,5913 g (.0,0048 mol} isonicotinic acid yield 100%, performance 1.6 kg / l,

Example 10 (for comparison). Analogously to example 1, I g (0.0096 mol 4-cyanopyridine, 0.577 g (0144 mol of caustic soda and 2.9 g 0.163 mol) of water (molar ratio nitrile: caustic soda: water is 1: 1.5: 17 ) heated for 5 min at 80 ° C. Obtain 0.5026 g (0.0081 mol) of the desired product, yield.42.5%, process capacity 2.1 kg / lH O-h

Example P (for comparison). Similarly, 1.2 g (0.0192 mol

4-cyanopyridine, 1.538 g (0.0288 mol of caustic soda and 5.9 g (0.3269 mol) of water (molar ratio nitrile:

1dish: water is 1: 1.5: 17). heating

1.50

1.65

1.50

1.00

1.75

2.00

1.50

1.50

1.50

1.50

1.50

1.50

17 17 14 17

17 17 10 6 25 17 17 17

As can be seen from the table, the most effective conditions for the alkaline hydrolysis of 4-cyanopyridine to an acid are: temperature 50–80 ° C. 9-10 min, molar ratios nitrile: sodium chloride: sodium: water. 1: (1.5-1.75): (10-17).

1834

for 10 min at 80t. Get 2,3653 g (0,0192 mol) of the desired product, yield 100%, performance I, 2 kg / l h.

Example 12 (for comparison), as in Example 1, 1 g (0.0096 mol) of 4-cyanopyridine, 0.577 g (0.0144 mol of caustic soda and 2.9 g (0.1634 mol) of water (molar ratio nitrile: caustic soda : water is 1: 1.5: 17). They are heated for 10 minutes at 40 ° C, 1.0348 g (0.0084 mol) of isonicotinic acid is obtained, yield 87.5%, process productivity. 2.1 kt / l h

The choice of the optimal parameters for the hydrolysis of 4-cyanopyridine to isonicotinic acid is given in tab.

99.5

99.9

99.9

81.5

99.9

99.9

99.9

89.3

100.0

42.5

100.0

67.5

2.7

2.9 1.97 2.7 2.4

4.1 6.1 1.6

2.1 1.2 2.1

Claims (1)

Invention Formula The method of obtaining isonicotinic acid, hydrolysis of 4-cyanopyridine with water in the presence of alkali at 50- (80 ° C with a subsequent release of the desired product by acidification of the hydrolysis cone, characterized by lizutot water in the presence of caustic that, with the aim of increasing the sodium-producer at a molar ratio of 4 process and reducing the amount of 11; ianpyridine: caustic soda: water, equal to WA wastewater 4-cyanpyridine hydro-1: (1.5 1.75) :( 10 - 17).