A Multidisciplinary Investigation to Determine the Structure and Source of Dimeric Impurities in AMG 517 Drug Substance

Table 4

Partial ¹H and ¹³C chemical shifts (δ /ppm) of the benzothiazole ring for AMG 517 and the enriched impurity fraction in DMSO-d6.

	^1H (𝛿/ppm, J/Hz)				^13C (𝛿/ppm)
Position	AMG 517^(a)	Unknown 2^(b)	Unknown 1^(b)	AMG 517^(a)	Unknown 2^(b)	Unknown 1^(b)
16	7.35 (m, 1H)^(c)	7.45 (d, 1H, J = 8.2 Hz)	7.59 (d, 1H, J = 8.0 Hz)	119.1	120.4	119.9
17	7.39 (t, 1H, J = 7.7 Hz)^(c)	7.49 (d, 1H, J = 8.2 Hz)	7.68 (d, 1H, J = 8.0 Hz)	124.2	128.1	123.9
18	7.93 (m, 1H)			119.6	122.6	131.2
19				133.6	136.6	132.8

^(a) Data from 400 MHz NMR instrument; ^(b) data from 600 MHz instrument; ^(c) overlapping signals.