Organic Lab Reactions 112

Organic Lab Reactions 112 - ortho positions also can...

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TRI- AND TETEA-SUBSTITUTED BENZALDEHYDES 107 reaction for 2,6-dihalo-, 2,6-dinitro-, and 2,4-dinitro-benzaldehydes are not tabulated but may be found in the articles referred to in Table IV. Tri- and Tetra-Substituted Benzaldehydes. No important devia- tion from the limitations discussed above are to be noted when further substituents are present, provided that at least one position ortho to the formyl group is open. When an ortho or para hydroxyl group is present neither dismutation nor cleavage occurs under the usual conditions of the reaction. An ortho-axaino group acts similarly; 2,5-dichloro-6- aminobenzaldehyde was recovered after treatment with 50% KOH at 100° for four hours. 78 Groups other than halogen or nitro in the two
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Unformatted text preview: ortho positions also can influence the mode of reaction. For example, while opianic acid can be transformed in good yield into hemipinic acid and meconine, 79 pseudo-opianic acid loses the formyl group under the influence of strong alkali. 8 ? CHO COOH a CH 3 OCH3 Fseudoopmnic acid + HCO 2-OCH 3 The reaction of hydrastinine with alkali is of special interest, since it leads to oxyhydrastinine and hydrohydrastinine. 81 ' OH-NHCH 8 CHO Hydrastinine CO Oxyhydrastinine 78 Lock, Ber., 68, 1605 (1935). " Beckett and Wright, J. Chem. Soc, 29, 281 (1876). 80 Perkin, Jr., J. Chem. Son., 57, 1054 (1890). 81 McGeoch and Stevens, J. Chem. Soc, 1934, 1465, CH 2 Hydrohydrastinine NCH 3...
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