4 results about "Chloral" patented technology

The invention relates to an L-proline heterocyclic intermediate, alpha-methyl-L-proline hydrochloride and a preparation method thereof, which comprises the following steps: step 01, cyclization upper protection: taking L-proline as a raw material, which is shown in a formula (1), to react with trichloracetic aldehyde hydrate under an acidic condition, and performing upper protection to obtain a heterocyclic intermediate as shown in a formula (2); the molar weight of chloral hydrate is 1-2.5 times of the molar weight of the L-proline shown in the formula (1), preferably 1.5 times of the molar weight of the L-proline shown in the formula (1). 02, methylation: reacting the heterocyclic intermediate as shown in the formula (2) obtained in the step 01 with lithium diisopropylamide, and after the reaction is completed, adding dimethyl sulfate for methylation to obtain an intermediate as shown in a formula (3); 03, deprotection: adding the intermediate as shown in the formula (3) obtained in the step 02 into a deprotection reagent for hydrolysis so as to obtain the alpha-methyl-L-proline hydrochloride as shown in the formula (4), so that the problems that the preparation cost of the existing alpha-methyl-L-proline hydrochloride is relatively high and the yield is relatively low can be solved.

The invention relates to the technical field of organic synthesis, in particular to a trichlorfon production device and a trichlorfon production process, the device comprises a first-stage synthesis kettle, a first-stage synthesis kettle condenser, a second-stage synthesis kettle, a second-stage synthesis kettle condenser and a centrifugal machine; a trichloroacetaldehyde feeding hole, a dimethyl phosphite feeding hole and a precipitant feeding hole are formed in the top of the first-stage synthesis kettle, an overflow hole is formed in the upper part of the side wall of the first-stage synthesis kettle, and the top of the first-stage synthesis kettle is connected with a first-stage synthesis kettle condenser through a pipeline; the second-stage synthesis kettle is communicated with an overflow port of the first-stage synthesis kettle through an overflow pipe, and the top of the second-stage synthesis kettle is connected with a second-stage synthesis kettle condenser through a pipeline; and the centrifugal machine is communicated with an overflow port of the second-stage synthesis kettle through an overflow pipe. According to the invention, a continuous synthesis method is adopted, and solid trichlorfon is immediately precipitated and separated out by adding a precipitant; meanwhile, two stages of synthesis kettles are arranged, so that solid trichlorfon is precipitated and separated out more sufficiently while the reaction retention time is ensured, the trichlorfon content is greater than or equal to 98%, and the yield is greater than or equal to 90%.

This invention belongs to the field of organic chemical synthesis technology, specifically relating to a method for synthesizing 2-fluoro-3-aminobenzoic acid, an important chemical intermediate. Specifically, o-nitroaniline is condensed with hydrated trichloroacetaldehyde and hydroxylamine hydrochloride to obtain 2-(hydroxyimino)-N-(2-nitrophenyl)acetamide; the resulting product undergoes an intramolecular Beckmann rearrangement to generate 7-nitroindigo; 7-nitroindigo undergoes Bayer-Villedge oxidation to generate 2-amino-3-nitrobenzoic acid; 2-amino-3-nitrobenzoic acid undergoes diazotization and halogenation reactions to generate 2-fluoro-3-nitrobenzoic acid or 2-chloro-3-nitrobenzoic acid; 2-fluoro-3-nitrobenzoic acid can be further reduced by nitro to obtain 2-fluoro-3-aminobenzoic acid; or, 2-chloro-3-nitrobenzoic acid can be esterified to obtain 2-chloro-3-nitrobenzoic acid ester, which can then be fluorinated, saponified, and reduced to obtain 2-fluoro-3-aminobenzoic acid. The raw materials of this invention are low in cost and readily available, and the entire reaction route has specific regioselectivity, making it suitable for industrial production.

The invention discloses 2-methyl-4-chlorophenoxyacetic acid esterification dehydration equipment and a synthesis method, belongs to the technical field of chemical engineering, and solves the problems that when 2-methyl-4-chlorophenoxyacetic acid isooctyl ester is synthesized in the prior art, a catalyst seriously corrodes production equipment, the service life of the equipment is shortened, and the product quality is affected due to the fact that the catalyst is left in a product. The method comprises the following steps: respectively adding 2-methyl-4-chloro-phenoxyacetic acid and isooctyl alcohol into a negative pressure reaction kettle, starting the negative pressure reaction kettle, discharging distilled water through a fraction discharging assembly, and obtaining 2-methyl-4-chloro-phenoxyacetic acid isooctyl ester when no fraction flows out of gas-phase isooctyl alcohol in the negative pressure reaction kettle; in the invention, during synthesis of 2-methyl-4-chloro-isooctyl, a catalyst is not needed to catalyze a raw material reaction, a catalyst-free esterification dehydration method is adopted, a negative pressure forced distillation technology is combined, water generated in the reaction is efficiently removed, and the reaction conversion rate and the product yield are remarkably improved; the problems that the catalyst corrodes reaction equipment and the residual catalyst in the product affects the purity and performance of the product are avoided.