221040-21-7 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 221040-21-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 2,2,1,0,4 and 0 respectively; the second part has 2 digits, 2 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 221040-21:
(8*2)+(7*2)+(6*1)+(5*0)+(4*4)+(3*0)+(2*2)+(1*1)=57
57 % 10 = 7
So 221040-21-7 is a valid CAS Registry Number.
221040-21-7Relevant articles and documents
Nucleophilic additions to fused benzimidazole N-oxides
Donaghy, Michael J.,Stanforth, Stephen P.
, p. 1441 - 1448 (2007/10/03)
The benzimidazoles 16a-f have been prepared from N-oxides 15a-d. Treatment of N-oxides 15c and 15d with a mixture of acetic anhydride and sodium acetate gave the corresponding acetoxy derivatives 26 and 27 via a regiospecific nucleophilic substitution rea