3-Bromo-m-meconine was prepared in three ways: (a) by direct brominalion of metameconine, (b) from 5-bromoveratric acid and formaldehyde, and (c) from 6-amino-m-meconine by a method which amounted to an independent derivation of the structures of 6-amino-m-meconine and its products of transformation. The structures obtained agreed with those previously reported by us. Carefully purified 6-bromo-m-meconine was found to melt at 207°C. in agreement with our previous work, rather than at 223°C. as reported by Rây and Robinson. During the investigation, a convenient synthesis of metaopianic acid was discovered, and the following new compounds were characterized: 6-acetamino-m-meconine, 6-diacetylamino-m-meconine, 6-acetamino-3-bromo-m-meconine, 6-amino-3-bromo-m-meconine, 2-iodoveratric acid, and 5-iodoveratric acid.
6-Iodo-m-meconine has been prepared from m-meconine by several steps and oxidized to 3-iodo-m-hemipinic acid. The orientation of the iodo-m-meconine is based on its conversion to 4, 5, 6-trimethoxyphthalide. The identity reported by Rây and Robinson of the bromo-m-meconine made directly by similar steps from m-meconine with that from 2-bromoveratric acid and formaldehyde could not be confirmed. The former substance has the orientation ascribed to it by Rây and Robinson but the identity and orientation of the latter substance is left in doubt. Attempts to form a substituted diphenyl ether from dimethyl 3-iodo-m-hemipinate and the potassium salt of methyl vanillate failed.