NMR Chemical Shifts of Impurities

Section Overview

• Using NMR Chemical Impurities Tables
• ¹H NMR Chemical Shifts Table
• ¹³C Chemical Shifts Table
• References

Using NMR Chemical Impurities Tables

These tables can support you in identifying and separating NMR signals of impurities that might originate from residual solvents or from your reaction apparatus. Here we present the NMR shifts of the most commonly used solvents and impurities in organic synthesis measured in the 7 most frequently used deuterated solvents. Please note that the values given in the tables are temperature- and partly concentration-dependent and therefore represent average values only. The ¹H-NMR data were obtained using a 300 MHz spectrometer, the ¹³C-NMR data using 75 MHz.

¹H NMR Chemical Impurity Shifts Table

	proton	mult	CDCl3	(CD3)2CO	(CD3)2SO	C6D6	CD3CN	CD3OD	D2O
Solvent residual peak			7.26	2.05	2.50	7.16	1.94	3.31	4.79
H2O		s	1.56	2.84	3.33	0.40	2.13	4.87
Acetic acid	CH3	s	2.10	1.96	1.91	1.55	1.96	1.99	2.08
Acetone	CH3	s	2.17	2.09	2.09	1.55	2.08	2.15	2.22
Acetonitrile	CH3	s	2.10	2.05	2.07	1.55	1.96	2.03	2.06
Benzene	CH	s	7.36	7.36	7.37	7.15	7.37	7.33
Tert-butyl alcohol	CH3 OH	s s	1.28	1.18	1.11 4.19	1.05 1.55	1.16 2.18	1.40	1.24
Tert-butyl methyl ether	CCH3 OCH3	s s	1.19 3.22	1.13 3.13	1.11 3.08	1.07 3.04	1.14 3.13	1.15 3.20	1.21 3.22
BHTa	ArH OH ArCH3 ArC(CH3)3	s s s s	6.98 5.01 2.27 1.43	6.96 2.22 1.41	6.87 6.65 2.18 1.36	7.05 4.79 2.24 1.38	6.97 5.20 2.22 1.39	6.92 2.21 1.40
Chloroform	CH	s	7.26	8.02	8.32	6.15	7.58	7.90
Cyclohexane	CH2	s	1.43	1.43	1.40	1.40	1.44	1.45
1,2-dichloro- ethane	CH2	s	3.73	3.87	3.90	2.90	3.81	3.78
Dichloro- methane	CH2	s	5.30	5.63	5.76	4.27	5.44	5.49
Diethyl ether	CH3 CH2	t, 7 q, 7	1.21 3.48	1.11 3.41	1.09 3.38	1.11 3.26	1.12 3.42	1.18 3.49	1.17 3.56
Diglyme	CH2 CH2 OCH3	m m s	3.65 3.57 3.39	3.56 3.47 3.28	3.51 3.38 3.24	3.46 3.34 3.11	3.53 3.45 3.29	3.61 3.58 3.35	3.67 3.61 3.37
1,2-dimeth- oxyethane	CH3 CH2	s s	3.40 3.55	3.28 3.46	3.24 3.43	3.12 3.33	3.28 3.45	3.35 3.52	3.37 3.60
Dimethyl- acetamide	CH3CO NCH3 NCH3	s s s	2.09 3.02 2.94	1.97 3.00 2.83	1.96 2.94 2.78	1.60 2.57 2.05	1.97 2.96 2.83	2.07 3.31 2.92	2.08 3.06 2.90
Dimethyl- formamide	CH CH3 CH3	s s s	8.02 2.96 2.88	7.96 2.94 2.78	7.95 2.89 2.73	7.63 2.36 1.86	7.92 2.89 2.77	7.97 2.99 2.86	7.92 3.01 2.85
Dimethyl sulfoxide	CH3	s	2.62	2.52	2.54	1.68	2.50	2.65	2.71
Dioxane	CH2	s	3.71	3.59	3.57	3.35	3.60	3.66	3.75
Ethanol	CH3 CH2 OH	t, 7 q, 7 s	1.25 3.72 1.32	1.12 3.57 3.39	1.06 3.44 4.63	0.96 3.34	1.12 3.54 2.47	1.19 3.60	1.17 3.65
Ethyl acetate	CH3CO CH2CH3 CH2CH3	s q, 7 t, 7	2.05 4.12 1.26	1.97 4.05 1.20	1.99 4.03 1.17	1.65 3.89 0.92	1.97 4.06 1.20	2.01 4.09 1.24	2.07 4.14 1.24
Ethyl methyl ketone	CH3CO CH2CH3 CH2CH3	s q, 7 t, 7	2.14 2.46 1.06	2.07 2.45 0.96	2.07 2.43 0.91	1.58 1.81 0.85	2.06 2.43 0.96	2.12 2.50 1.01	2.19 3.18 1.26
Ethylene glycol	CH	s	3.76	3.28	3.34	3.41	3.51	3.59	3.65
“Grease”	CH3 CH2	m br s	0.86 1.26	0.87 1.29		0.92 1.36	0.86 1.27	0.88 1.29
N-hexane	CH3 CH2	t m	0.88 1.26	0.88 1.28	0.86 1.25	0.89 1.24	0.89 1.28	0.90 1.29
HMPAb	CH3	d, 9.5	2.65	2.59	2.53	2.40	2.57	2.64	2.61
Methanol	CH3 OH	s s	3.49 1.09	3.31 3.12	3.16 4.01	3.07	3.28 2.16	3.34	3.34
Nitromethane	CH3	s	4.33	4.43	4.42	2.94	4.31	4.34	4.40
n-pentane	CH3 CH2	t, 7 m	0.88 1.27	0.88 1.27	0.86 1.27	0.87 1.23	0.89 1.29	0.90 1.29
2-propanol	CH3 CH	d, 6 sep, 6	1.22 4.04	1.10 3.90	1.04 3.78	0.95 3.67	1.09 3.87	1.50 3.92	1.17 4.02
Pyridine	CH(2) CH(3) CH(4)	m m m	8.62 7.29 7.68	8.58 7.35 7.76	8.58 7.39 7.79	8.53 6.66 6.98	8.57 7.33 7.73	8.53 7.44 7.85	8.52 7.45 7.87
Silicone grease	CH3	s	0.07	0.13		0.29	0.08	0.10
Tetrahydro- furan	CH2 CH2O	m m	1.85 3.76	1.79 3.63	1.76 3.60	1.40 3.57	1.80 3.64	1.87 3.71	1.88 3.74
Toluene	CH3 CH(o/p) CH(m)	s m m	2.36 7.17 7.25	2.32 7.1 – 7.2 7.1 – 7.2	2.30 7.18 7.25	2.11 7.02 7.13	2.33 7.1 – 7.3 7.1 – 7.3	2.32 7.16 7.16
Triethyl- amine	CH3 CH2	t, 7 q, 7	1.03 2.53	0.96 2.45	0.93 2.43	0.96 2.40	0.96 2.45	1.05 2.58	0.99 2.57
a 2,6-Dimethyl-4-tert-butylphenol b Hexamethylphosophoramide

¹³C NMR Chemical Impurity Shifts Table

	carbon	CDCl3	(CD3)2CO	(CD3)2SO	C6D6	CD3CN	CD3OD	D2O
Solvent signals		77.16 ± 0.06	29.84 ± 0.01 206.26 ± 0.13	39.52 ± 0.06	128.06 ±0.02	1.32 ± 0.02 118.26 ± 0.02	49.00 ±0.01
Acetic acid	CO CH3	175.99 20.81	172.31 20.51	171.93 20.95	175.82 20.37	173.21 20.73	175.11 20.56	177.21 21.03
Acetone	CO CH3	207.07 30.92	205.87 30.60	206.31 30.56	204.43 30.14	207.43 30.91	209.67 30.67	215.94 30.89
Acetonitrile	CN CH3	116.43 1.89	117.60 1.12	117.91 1.03	116.02 0.20	118.26 1.79	118.06 0.85	119.68 1.47
Benzene	CH	128.37	129.15	128.30	128.62	129.32	129.34
Tert-butyl alcohol	C CH3	69.15 31.25	68.13 30.72	66.88 30.38	68.19 30.47	68.74 30.68	69.40 30.91	70.36 30.29
Tert-butyl methyl ether	CCH3 C CCH3	49.45 72.87 26.99	49.35 72.81 27.24	48.70 72.04 26.79	49.19 72.40 27.09	49.52 73.17 27.28	49.66 74.32 27.22	49.37 75.62 26.60
BHT	C(1) C(2) CH(3) C(4) CH3Ar CH3C C	151.55 135.87 125.55 128.27 21.20 30.33 34.25	152.51 138.19 129.05 126.03 21.31 31.61 35.00	151.47 139.12 127.97 124.85 20.97 31.25 34.33	152.05 136.08 128.52 125.83 21.40 31.34 34.35	152.42 138.13 129.61 126.38 21.23 31.50 35.05	152.85 139.09 129.49 126.11 21.38 31.15 35.36
Chloroform	CH	77.36	79.19	79.16	77.79	79.17	79.44
Cyclo-hexane	CH2	26.94	27.51	26.33	27.23	27.63	27.96
1,2-dichloroe- thane	CH2	43.50	45.25	45.02	43.59	45.54	45.11
Dichloro-methane	CH2	53.52	54.95	54.84	53.46	55.32	54.78
Diethyl ether	CH3 CH2	15.20 65.91	15.78 66.12	15.12 62.05	15.46 65.94	15.63 66.32	15.46 66.88	14.77 66.42
Diglyme	CH3 CH2 CH2	59.01 70.51 71.90	58.77 71.03 72.63	57.98 69.54 71.25	58.66 70.87 72.35	58.90 70.99 72.63	59.06 71.33 72.92	58.67 70.05 71.63
1,2-dimethoxy- ethane	CH3 CH2	59.08 71.84	58.45 72.47	58.01 17.07	58.68 72.21	58.89 72.47	59.06 72.72	58.67 71.49
Dimethyl-acetamide	CH3 CO NCH3 NCH3	21.53 171.07 35.28 38.13	21.51 170.61 34.89 37.92	21.29 169.54 37.38 34.42	21.16 169.95 34.67 37.03	21.76 171.31 35.17 38.26	21.32 173.32 35.50 38.43	21.09 174.57 35.03 38.76
Dimethyl-formamide	CH CH3 CH3	162.62 36.50 31.45	162.79 36.15 31.03	162.29 35.73 30.73	162.13 35.25 30.72	163.31 36.57 31.32	164.73 36.89 31.61	165.53 37.54 32.03
Dimethyl sulfoxide	CH3	40.76	41.23	40.45	40.03	41.31	40.45	39.39
Dioxane	CH2	67.14	67.60	66.36	67.16	67.72	68.11	67.19
Ethanol	CH3 CH2	18.41 58.28	18.89 57.72	18.51 56.07	18.72 57.86	18.80 57.96	18.40 58.26	17.47 58.05
Ethyl acetate	CH3CO CO CH2 CH3	21.04 171.36 60.49 14.19	20.83 170.96 60.56 14.50	20.68 170.31 59.74 14.40	20.56 170.44 60.21 14.19	21.16 171.68 60.98 14.54	20.88 172.89 61.50 14.49	21.15 175.26 62.32 13.92
Ethyl methyl ketone	CH3CO CO CH2CH3 CH2CH3	29.49 209.56 36.89 7.86	29.30 208.30 36.75 8.03	29.26 208.72 35.83 7.61	28.56 206.55 36.36 7.91	29.60 209.88 37.09 8.14	29.39 212.16 37.34 8.09	29.49 218.43 37.27 7.87
Ethylene glycol	CH2	63.79	64.26	62.76	64.34	64.22	64.30	63.17
“Grease”	CH2	29.76	30.73	29.20	30.21	30.86	31.29
N-hexane	CH3 CH2(2) CH2(3)	14.14 22.70 31.64	14.34 23.28 32.30	13.88 22.05 30.95	14.32 23.04 31.96	14.43 23.40 32.36	14.45 23.68 32.73
HMPA	CH3	36.87	37.04	36.42	36.88	37.10	37.00	36.46
Methanol	CH3	50.41	49.77	48.59	49.97	49.90	49.86	49.50
Nitro-methane	CH3	62.50	63.21	63.28	61.16	63.66	63.08	63.22
N-pentane	CH3 CH2(2) CH2(3)	14.08 22.38 34.16	14.29 22.98 34.83	13.28 21.70 33.48	14.25 22.72 34.45	14.37 23.08 34.89	14.39 23.38 35.30
2-propanol	CH3 CH	25.14 64.50	25.67 63.85	25.43 64.92	25.18 64.23	25.55 64.30	25.27 64.71	24.38 64.88
Pyridine	CH(2) CH(3) CH(4)	149.90 123.75 135.96	150.67 124.57 136.56	149.58 123.84 136.05	150.27 123.58 135.28	150.76 127.76 136.89	150.07 125.53 138.35	149.18 125.12 138.27
Silicone grease	CH3	1.04	1.40		1.38		2.10
Tetrahydro-furan	CH2 CH2O	25.62 67.97	26.15 68.07	25.14 67.03	25.72 67.80	26.27 68.33	26.48 68.83	25.67 68.68
Toluene	CH3 CH(i) CH(o) CH(m) CH(p)	21.46 137.89 129.07 128.26 125.33	21.46 138.48 129.76 129.03 126.12	20.99 137.35 128.88 128.18 125.29	21.10 137.91 129.33 128.56 125.68	21.50 138.90 129.94 129.23 126.28	21.50 138.85 129.91 129.20 126.29
Triethyl-amine	CH3 CH2	11.61. 46.25	12.49 47.07	11.74 45.74	12.35 46.77	12.38 47.10	11.09 46.96	9.07 47.19

References

1. Gottlieb HE, Kotlyar V, Nudelman A. 1997. J.Org.Chem., 62, 7512.