20039-37-6 Usage
Description
Pyridinium dichromate (PDC) is a pyridinium salt that is the dipyridinium salt of dichromic acid. It is an orange-colored solid and a strong oxidizing agent capable of converting primary and secondary alcohols to aldehydes and ketones, respectively. It has a role as an oxidizing agent and contains a dichromate(2-).
Uses
Used in Organic Chemistry:
Pyridinium dichromate is used as an oxidizing agent for the conversion of primary alcohols to aldehydes and ketones, acetals to esters, and didehydroketones to enones in the presence of tert-butyl hydroperoxide. It plays an important role in the oxidation of unsaturated tertiary alcohols, silyl ethers, the carbon-boron bond, and oximes.
Used as an Alternative to PCC:
Pyridinium dichromate may be used as an alternative to pyridinium chlorochromate (PCC) in nucleoside and carbohydrate oxidation, particularly for fragile molecules. PDC can also be used in conjunction with tert-butyl hydroperoxide for a variety of oxidative transformations.
Preparation
Pyridinium dichromate can be obtained by gradual addition of a solution of chromic anhydride (Cr2O3) in water to pyridine in ice cold conditions.
Flammability and Explosibility
Flammable
Purification Methods
Dissolve it in the minimum volume of H2O and add 5 volumes of cold Me2CO and cool to -20o. After 3hours the orange crystals are collected, washed with a little cold Me2CO and dried in a vacuum. It is soluble in dimethylformamide (0.9g/mL at 25o), and in H2O, and has a characteristic IR with max at 930, 875, 765, 730 and 730 cm-1. [Corey & Schmidt Tetrahedron Lett 399 1979, Coats & Corrigan Chem Ind (London) 1594 1969.] (Possible CARCINOGEN.) § Available commercially on a polymer support.
Check Digit Verification of cas no
The CAS Registry Mumber 20039-37-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,0,0,3 and 9 respectively; the second part has 2 digits, 3 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 20039-37:
(7*2)+(6*0)+(5*0)+(4*3)+(3*9)+(2*3)+(1*7)=66
66 % 10 = 6
So 20039-37-6 is a valid CAS Registry Number.
InChI:InChI=1/2C5H5N.2Cr.7O/c2*1-2-4-6-5-3-1;;;;;;;;;/h2*1-5H;;;;;;;;;/q;;;;;;;;;2*-1/p+2/r2C5H5N.Cr2O7/c2*1-2-4-6-5-3-1;3-1(4,5)9-2(6,7)8/h2*1-5H;/q;;-2/p+2
20039-37-6Relevant articles and documents
Preparing method for EXP-3174
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Paragraph 0018, (2016/10/09)
The invention discloses a preparing method for EXP-3174. The preparing method is characterized in that losartan is used as a starting raw material and is prepared into EXP-3174 through two-step oxidation. The preparing method has the greatest advantages that a reaction is moderate, the number of side reactions is small, aftertreatment is simple, and EXP-3174 with the purity of 99.9% can be obtained without column chromatography isolation.