Superiority PackingStandard packaging includes the following: 25kg/drum Other package sizes are available upon request. StorageStore in a well-ventilated, cool, dry area, out of direct sunlight. Keep containers tightly closed when not in use. Period of validity24 months ? Product Superiority ? 1.High quality
PackingStandard packaging includes the following: 25kg/drum Other package sizes are available upon request.
StorageStore in a well-ventilated, cool, dry area, out of direct sunlight. Keep containers tightly closed when not in use.
Period of validity24 months
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Product Superiority
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1.High quality with best price
2.Well reputation
3.Factory with strong supply ability
4. Prompt shipment
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Packing & Delivery
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FAQ
1. who are we? We are based in Shandong, China, start from 2014,sell to Southern Europe(00.00%),Domestic Market(00.00%),South America(00.00%),North America(00.00%),Eastern Europe(00.00%),Africa(00.00%),Eastern Asia(00.00%). There are total about 11-50 people in our office. 2. how can we guarantee quality? Always a pre-production sample before mass production; Always final Inspection before shipment3. why should you buy from us not from other suppliers? Have a strong ability to warehousing logistics and release permit of dangerous goods export right and use right, has a strong factory as a backstop. 4. what services can we provide? Accepted Delivery Terms: FOB,CFR,CIF,EXW； Accepted Payment Currency :USD; Accepted Payment Type: T/T,L/C; Language Spoken:English,Chinese
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Our services
<1> Free samples for customer further evaluation before order and after production.
<2>Quality controlling throughout the production,inspection and shipment.
<3> Packing according to customers requirements.
<4> the nearest port to customer site,very convenient for discharge
<5> Complete documents for customer customs clerance
Friends at home and abroad, welcome to our company.
Want to get the latest best offer call me NOW!!! PLEASE CONTACT ME !!!!!!!
Applications
(R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, also known as R-glyceraldehyde acetal, is an intermediate in the synthesis of gemcitabine. Gemcitabine hydrochloride is a novel synthetic difluoronucleoside antimetabolite and antitumor drug, first developed by Eli Lilly in the United States under the trade name "Genza". Gemcitabine hydrochloride inhibits DNA synthesis.
Preparation
In a clean reactor, 220g of dichloromethane, 23g of diacetone-D-mannitol, 0.23g of 18-crown-6-ether, and 0.4g of TEMPO were added sequentially. After stirring and mixing thoroughly, the mixture was slowly cooled to 10°C. Then, 72g of a 10wt% sodium hypochlorite aqueous solution was added dropwise, maintaining the reaction temperature below 15°C during the addition. After the addition was complete, the reaction was continued at 30°C–32°C for oxidation. After the reaction was completed, the mixture was allowed to stand and separate into layers. The aqueous layer was removed, and the collected organic layer was washed once with 50g of water. The aqueous layer was removed again, and 20g of anhydrous sodium sulfate was added to the collected organic layer. The mixture was then stirred and dried for 30 minutes. The mixture was filtered, and the filtrate was collected. The filtrate was concentrated under reduced pressure to remove the solvent. The resulting wet product was dried to obtain 22.1g of (R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, with a yield of 97% and a gas phase content of 99.2%.
