number atom shift 1 N 309.479 2 C 121.743 3 C 141.051 4 C 141.051 5 C 135.661 6 C 135.661 7 C 138.678 8 C 128.892 9 H 9.060 10 H 9.060 11 H 8.726 12 H 8.726 13 H 8.792