21240-57-3 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 21240-57-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,1,2,4 and 0 respectively; the second part has 2 digits, 5 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 21240-57:
(7*2)+(6*1)+(5*2)+(4*4)+(3*0)+(2*5)+(1*7)=63
63 % 10 = 3
So 21240-57-3 is a valid CAS Registry Number.
21240-57-3Relevant academic research and scientific papers
Photochemical formylation of carbazole and diphenylamine
Chowdhury,Saha,Podder
, p. 405 - 406 (2007/10/02)
Carbazole (1) and diphenylamine (7) undergo photo-chemical formylation in chloroform solution to furnish the corresponding formyl derivatives 2, 3 and 8, 9 respectively. The reaction has been successfully extended to 1-methylcarbazole (4) to yield formyl derivatives 5 and 6.
