Picloram synthesis

3synthesis methods

Product Name:Picloram
CAS Number:1918-02-1
Molecular formula:C6H3Cl3N2O2
Molecular Weight:241.46

The synthesis of picloram typically begins with the chlorination of picolinic acid or its derivatives to introduce three chlorine atoms at specific positions on the aromatic ring. This is followed by an ammonolysis reaction, where ammonia is used to replace a leaving group with an amino group at the 4-position. In modern industrial settings, this process is carried out in a slurry-phase reactor, which allows for continuous production and improved reaction efficiency. The reaction conditions, such as temperature, pressure, and pH, are carefully controlled to maximise yield and minimise impurities.

METHYL 3,4,5,6-TETRACHLOROPYRIDINE-2-CARBOXYLATE

35592-96-2
12 suppliers
$28.60/100mg

1918-02-1
291 suppliers
$14.14/1gm:

Yield:1918-02-1 95.5%

Reaction Conditions:

with ammonia in methanol;lithium hydroxide monohydrate at 120 - 130; for 8 h;Autoclave;Large scale;

Steps:

1.1-1.2; 2.1-2.2; 1 1) Ammonolysis reaction

Into a 2L autoclave, add 281 g of methyl 3,4,5,6-tetrachloropicolinate (97.9%), 1200 g of methanol (1500 ml), and 50 ml of water. After the addition is completed, the autoclave is closed, and the temperature is kept at 20 under stirring. 170 grams of ammonia gas was slowly introduced into it within .The autoclave was heated to 120-130° C., and the reaction was maintained for 8 hours. After sampling, the HPLC tracked that the residual 3,4,5,6-tetrachloropicolinic acid (intermediate product) was no higher than 1% to complete the reaction.2) Post-processingAfter cooling the material, transfer it to a distillation flask to remove the solvent at normal pressure, the liquid temperature is 80-85 °C, and receive about 1270-1300 grams of methanol-ammonia solution, add 200 ml of water, continue to distill until the liquid temperature is 98-100 °C, stop Distilled.Stir to cool down and add 100 grams of industrial hydrochloric acid (36%) dropwise to determine whether pH=2 is reached, if not, continue to add a small amount of hydrochloric acid to pH=1-2, and end the dropwise addition.The material was heated to 50-60°C, matured and grown for 2 hours, cooled to below 30°C, filtered and rinsed with 100ML water, and dried to obtain 234.9 g of finished product of amlidine. The purity was 98.2% as determined by high performance liquid chromatography, and the yield was 95.5%. .

References:

CN114702440,2022,A Location in patent:Paragraph 0046-0053

1336-21-6 Synthesis

1336-21-6
744 suppliers
$14.56/250ML

3,4,5,6-Tetrachloropyridine-2-carbonitrile

17824-83-8
75 suppliers
$66.00/5mg

1918-02-1
291 suppliers
$14.14/1gm:

References

4-AMINO-3,5,6-TRICHLORO-2-(TRICHLOROMETHYL)PYRIDINE

5005-62-9
12 suppliers
inquiry

28443-69-8 Synthesis

28443-69-8
64 suppliers
$45.00/10mg

1918-02-1
291 suppliers
$14.14/1gm:

References

Picloram Related Search:

3-Aminopyridine 2,3,5-TRICHLORO-4-PYRIDINOL 4-Dimethylaminopyridine 2,5-PYRIDINEDICARBOXYLIC ACID 6-Aminocaproic acid 2,4,6-Trichloropyridine Glycine PHYTIN Phytic acid 3,5,6-TRICHLORO-4-HYDRAZINO-PYRIDINE-2-CARBOXYLIC ACID