An expeditious synthesis of imides from phthalic, maleic and succinic anhydrides and chemoselective C=C reduction of maleic amide esters

392-398Phthalic, maleic and succinic anhydrides have been reacted with<span style="mso-fareast-font-family:Calibri;mso-ansi-language: EN-IN"> aromatic amines to obtain the corresponding monoacid monoamides.<span style="mso-fareast-font-family: Calibri;mso-ansi-language:EN-IN" lang="EN-GB"> The latter have been each transformed into the corresponding cyclic imide derivatives by treating with SOCl2. Alternatively,<b style="mso-bidi-font-weight: normal"> anhydrides have been<span style="mso-fareast-font-family:Calibri;mso-ansi-language: EN-IN"> reacted with methanolic KOH to obtain monomethyl ester derivatives which on reaction with aromatic amines in the presence of EDC. HCl and HOBt <span style="mso-fareast-font-family:Calibri; mso-ansi-language:EN-IN">give cyclic imide derivatives. Reaction of monoacid monoamides<span style="mso-fareast-font-family:Calibri; mso-ansi-language:EN-IN"> independently, with SOCl2 at 0-5°<span style="mso-fareast-font-family:Calibri;mso-ansi-language: EN-IN">C give the monoamide monoester derivatives.<span style="mso-fareast-font-family:Calibri;mso-ansi-language:EN-IN;mso-fareast-language: EN-IN"> Treatment of <span style="mso-fareast-font-family: Calibri;mso-ansi-language:EN-IN">monoamide monoester of malic anhydride with NaBH4 leads to the unusual reduction of C=C grouping as well as the carbonyl group of the ester group to from monoamide monoalcohol of succinic anhydride. Preparation of monoamide monoalcohol of succinic anhydride can also be achieved by chemoselective reduction of <span style="mso-fareast-font-family: Calibri;mso-ansi-language:EN-IN">monoamide monoester of malic anhydride with Mg turnings yielding <span style="mso-fareast-font-family: Calibri;mso-ansi-language:EN-IN">monoamide monoester of succinic anhydride followed by reduction of the latter with NaBH4.