7 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.

The invention belongs to the field of pesticide synthesis, and particularly relates to a synthesis process and a synthesis system of dichlorvos. The dichlorvos synthesis system provided by the invention comprises a mixer, a synthesis kettle, an inner coil cooler, a condenser, a demister, a purification kettle and a washing tower, wherein silk screen holes with the aperture of 0.5-5 microns are formed in the demister; the synthesis method comprises the following steps: adding trimethyl phosphite and trichloroacetaldehyde into a synthesis kettle through a mixer, reacting at the temperature of 60-90 DEG C and the pressure of-10-0kPa, and condensing, demisting and recovering chloromethane; reaction liquid enters a purification kettle and is vaporized and purified at the temperature of 75-95 DEG C and the pressure smaller than or equal to-80 kPa, and gas-phase dichlorvos is collected after being subjected to reflux impurity removal, secondary condensation and demisting through a washing tower. The dichlorvos crude oil with the content larger than or equal to 99% can be prepared, the raw material conversion rate is larger than or equal to 99.5%, the method is suitable for large-scale production, and economical efficiency and stability are both considered.

The invention provides a paraffin section elastic fiber overdyeing basic fuchsin composite dyeing kit and a dyeing method thereof, and belongs to the technical field of pathology, a dyeing reagent in the dyeing kit is prepared from the following raw materials in percentage by weight: 4% of basic fuchsin, 50% of AR pure methanol, 0.3% of thymol, 0.6% of chloral hydrate, 1.5% of phenol and 43.6% of pure water. The dyeing step is simplified, the dyeing time is shortened, the experiment cost is reduced, the pathological diagnosis efficiency is improved, the dyed elastic fiber is specifically red, the display is clear, the background is clean, the stability and repeatability of the dyeing effect are improved, the dyeing error is reduced, the dyeing specificity is improved, non-specific dyeing is reduced, and observation and diagnosis are facilitated.

The utility model discloses a continuous distillation purification equipment for trichloroacetaldehyde refining, including base, the top fixed coupling of base has the retort, the front side of retort is installed with temperature controller, the top left side fixed coupling of retort has the feeding pipe, installs the valve on the feeding pipe. The utility model discloses a connecting mechanism is set up, when the condenser needs maintenance, anticlockwise rotation handle, the screw rod rotation drives second clamping block to move to the appropriate height upwards, and then makes second clamping block separate from second card slot, then pulls up condenser, makes first clamping block separate from first card slot to the air inlet pipe, and makes the jack from the jack, thereby can take down condenser from retort, and the staff is convenient to the maintenance of condenser, greatly saves the maintenance time and manpower, and the production efficiency has been improved.