Caronic Anhydride CAS 67911-21-1

Product Description:

Product Name:Caronic anhydride CAS 67911-21-1

Synonyms:

6,6-dimethyl-3-oxabicyclo[3.1.0]hexane-2,4-dione;

Meldrum's acid;

3,3-Dimethyl-1,2-cyclopropanedicarboxylic Anhydride

Chemical & Physical Properties

Appearance: White to Almost white powder to crystal

Density:1.3±0.1 g/cm3

Boiling Point:246.3±9.0ºC at 760 mmHg

Melting Point:52-55ºC

Flash Point:112.7±15.9 °C

Exact Mass:140.047348

PSA :43.37000

LogP:-0.42

Vapour Pressure:0.0±0.5 mmHg at 25°C

Index of Refraction :1.499

Safety Information

HazardClass :IRRITANT

HS Code :2914199090

Uses:

Karonic anhydride, also called 6,6-dimethyl-3-oxabicyclo [3.1.0] hexane-2,4-dione, is a pharmaceutical intermediate, mainly used as the synthesis of Boceprevir, an oral chemobook protease inhibitor of hepatitis C. Boceprevir is an oral hepatitis C protease inhibitor developed by Schering-Plough without modification.

Caronic anhydride can be used as a pharmaceutical intermediate, mainly for the synthesis of oral hepatitis C protease inhibitor Boceprevir.

Step 1: Add 200g of ethyl acetate to a 500mL flask, then add 94.8g (0.4mol) of ethyl dichloroferrate, cool to -5 ℃, and start the reaction with a flow rate of 2L/min by introducing ozone with a volume concentration of 3% (the remaining amount is air, the same below). During the reaction, analyze the raw materials through gas chromatography. After the conversion rate of ethyl dichloroferrate exceeds 99%, stop the ozone injection. After the reaction is completed, water is added to wash and layer the oil layer, washing twice, with 100ml of water each time. After washing, the oil layer is evaporated and concentrated to remove the solvent. Then, 70g of 30% liquid alkali is added to the remaining reaction end material for saponification reaction. At this time, the pH is greater than 12, and the reaction is kept at a temperature of 50-60 ℃ for 2 hours. Then, 30% hydrochloric acid is added to the reaction solution for acidification reaction until the pH value reaches 1-2, and the reaction temperature is controlled at 40-50 ℃, Insulation reaction for 1 hour. After falling to room temperature, extract with Chemicalbook methyl tert butyl e-ther, 100ml each time, three times, and merge the obtained organic layer solution. Concentrate the solvent by vacuum evaporation at 50mmHg to obtain 57.3g of 3,3-dimethyl-1,2-cyclopropane dicarboxylic acid, with a GC normalized content of 98.2% and a molar yield of about 84%. Step 2: Add 50g of 3,3-dimethyl-1,2-cyclopropane dicarboxylic acid to the reaction bottle, then add 30g of acetic anhydride and 0.5g of sodium acetate, and then heat up to 170 ° C for reaction. During the heating process, some of the acetic acid and acetic anhydride generated during the reaction are removed. After the reaction is completed, cool down to 50-70 ° C and perform negative pressure desorption to obtain 37.6g of the product. Then, add 30ml of toluene and 90ml of petroleum e-ther for recrystallization, 33.2g of 6,6-dimethyl-3-oxabicyclo [3.1.0] hexane-2,4-dione was obtained, with a normalized content of 99.6% and a yield of 74.8%.

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