91872-02-5 Usage
Preparation
4-amino-3,5-dichloropyridine-N-oxide is prepared by the following steps:A sealed Carius tube containing 4-nitro-3,5-dichloropyridine-N-oxide (36) (0.4 ?g, 1.9 mmol), aqueous ammonia (1 cm3 of 0.88 gi-l solution) and acetonitrile (1 cm3) ?was heated in a rotating oil bath at 70 OC for 3 h. The mixture was filtered giving a solid ?(0.1 g) and a filtrate, which was extracted into DCM, dried (MgS04) and evaporated ?giving a residue (0.0 g). The solid obtained from the filtration was recrystallised from hot ?methanol giving 4-amino-3,5-dichloropyridine-N-oxide (0.1 g, 30%), m.p. 210 oC from ?MeOH) (M+ found 177.9701. C5H4Cl2N20 requires M+ 177.9701); IR spectra no. 30; ?mass spectra no. 37; nmr spectrum no. 45.
Uses
4-Amino-3,5-dichloropyridine N-Oxide is the impurity of the drug Roflumilast (R639700), which is a selective phosphodiesterase 4(PDE4) inhibitor, antiasthmatic.
Check Digit Verification of cas no
The CAS Registry Mumber 91872-02-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,1,8,7 and 2 respectively; the second part has 2 digits, 0 and 2 respectively.
Calculate Digit Verification of CAS Registry Number 91872-02:
(7*9)+(6*1)+(5*8)+(4*7)+(3*2)+(2*0)+(1*2)=145
145 % 10 = 5
So 91872-02-5 is a valid CAS Registry Number.
InChI:InChI=1/C5H5Cl2N2O/c6-3-1-9(10)2-4(7)5(3)8/h1-2,10H,8H2
91872-02-5Relevant articles and documents
NOVEL HETEROCYCLIC COMPOUNDS USEFUL FOR THE TREATMENT OF INFLAMMATORY AND ALLERGIC DISORDERS: PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
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Page/Page column 45, (2009/12/24)
The present invention relates to novel Phosphodiesterase type 4 (PDE4) inhibitors of the formula (1) and analogs, tautomers, enantiomers, a diasteromers, regioisomers, stereoisomers, polymorphs, pharmaceutically acceptable salts, appropriate N-oxides, pharmaceutically acceptable solvates thereof and the pharmaceutical compositions containing them which are useful in the treatment of allergic and inflammatory diseases including asthma, chronic bronchitis, atopic dermatitis, urticaria, allergic rhinitis, allergic conjunctivitis, vernal conjunctivitis, eosinophilic granuloma, psoriasis, rheumatoid arthritis, septic shock, ulcerative colitis, Crohn's disease, reperfusion injury of the myocardium and reperfusion injury of the brain, chronic glomerulonephritis, endotoxic shock and adult respiratory distress syndrome.
SYNTHESIS OF QUINOLINE 5-CARBOXAMIDES USEFUL FOR THE PREPARATION OF PDE IV INHIBITORS
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Page/Page column 22-23, (2010/02/11)
In one embodiment, the present application discloses a process for making the compound of the formula:
