Structural commentary

Compound (I) possesses an intramolecular hydrogen bond between the N-H on C2 and the carbonyl at C1 (Table 1). This H-bond can more easily be seen in the space-filling model of Compound (I) (Fig. 5). The intramolecular interaction forms a 5-membered ring with an angle between the donor N-H and the C=O of 109 (2)°. The C2-N-H bond angle [115 (2)°] is biased toward the carbonyl. The distance between the donor H and the acceptor carbonyl oxygen is 2.20 (2) Å, shorter than expected due to the bulkiness of the tert-butyl group (vide infra).