57440-57-0 Usage
Synthesis
A 250-mL round-bottomed flflask equipped with a Dean–Stark trap and reflflux condenser was charged with the ketone (5.2 g, 33.3 mmol) and pyrrolidine (2.4 mL, 33.3 mmol) in anhydrous benzene (200 mL). The solution was reflfluxed for 8 h until no more H2O was collected in the Dean–Stark trap. The Dean–Stark trap was removed and replaced with a distillation head, and the benzene was removed by distillation. The product was distilled (0.2 torr, 105 oC) to give the enamine (4.78 g, 69%) as a yellow viscous oil, which was used immediately to avoid decomposition. Reference: Davis, K. M.; Carpenter, B. K. J. Org. Chem. 1996, 61, 4617–4622.
Check Digit Verification of cas no
The CAS Registry Mumber 57440-57-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,7,4,4 and 0 respectively; the second part has 2 digits, 5 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 57440-57:
(7*5)+(6*7)+(5*4)+(4*4)+(3*0)+(2*5)+(1*7)=130
130 % 10 = 0
So 57440-57-0 is a valid CAS Registry Number.
