3,4‐Dihydro‐3‐methyl‐6‐nitro‐2H‐1,3‐benzoxazin‐2‐one and p‐Nitrophenyl Dimethylcarbamate

In 3,4-dihydro-3-methyl-6-nitro-2H-1,3-benzoxazin-2-one (C 9 H 8 N 2 O 4 ) (1), the plane of the cis carbamate group is 11.1 (2)° to that of the benzene ring, whereas, in the acyclic analogue, p-nitrophenyl dimethylcarbamate (C 9 H 10 N 2 O 4 ) (2), the corresponding angle is 51.88 (9)° and the configuration is transoid. In (1), the O1-C7-O2 angle is 115.4(3)° and the O1-C7-N1 angle is 117.3 (2)° ; in (2), the corresponding angles are 122.8 (2) and 110.8 (2)°, respectively.