A Simplified Procedure for the Efficient Conversion of Aromatic Aldehydes into Esters

References and notes

• Corey , E. J. , Gilman , N. W. and Ganem , B. E. 1968 . J. Am. Chem. Soc. , 90 : 5616
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• Corey , E. J. , Kalzenellenbogen , J. A. , Gilman , N. W. , Roman , S. A. and Erickson , B. W. 1968 . J. Am. Chem. Soc. , 90 : 5618
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• Unpublished results; aldehyde 1a was synthesized in nine steps from indoline.
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• Methyl ester 1b: a pale brown oily liquid; Rf 0.38 (EtOAc-hexanes, 1:2); 1H NMR (CDCl3) δ 9.16 (s, broad, 1 H, NH), 8.06 (d, J = 7.7 Hz, 1 H), 7.95 (d, J = 3.0 Hz, 1 H), 7.20 (t, J = 7.2-8.1 Hz, 1 H), 7.06 (d, J = 7.2 Hz, 1 H), 5.50 (t, 1 H), 3.92 (s, 3 H), 3.65 (d, J = 7.1 Hz, 2 H), 3.62 (s, 3 H), 2.54 (t, J = 6.1-6.5 Hz, 2 H), 2.42 (t, J = 6.1-6.6 Hz, 2 H), 1.84 (s, 3 H); 13C NMR (CDCl3) δ 174.75, 166.56, 136.26, 135.99, 132.06, 126.67, 124.87, 123.49, 123.23, 122.54, 119.93, 108.91, 52.20, 51.57, 35.09, 32.64, 31.23, 16.58; IR (neat) 3333, 2952, 1733, 1705, 1535, 1442, 1245, 1193, 1159 cm−1. Anal. calcd for C10H21NO4: C, 68.55; H, 6.71; N, 4.44. Found: C, 68.32; H, 6.70; N, 4.38.
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• Methyl benzoate: 1H NMR (CDCl3) δ 8.02 (d, J = 7.1 Hz, 2 H), 7.52 (t, J = 7.5 Hz, 1 H), 7.42-7.37 (t, J = 7.2-7.7 Hz, 2 H), 3.88 (s, 3 H); Ethyl benzoate: 1H NMR (CDCl3) δ 8.04 (d, J = 7.2 Hz, 2 H), 7.55 (t, J = 7.4 Hz, 1 H), 7.44-7.39 (t, J = 7.3-7.8 Hz, 2 H), 4.39 (q, J = 7.2 Hz, 2 H), 1.38 (t, J = 7.2 Hz, 3 H); Methyl m-anisate: 1H NMR (CDCl3) δ 7.60-7.57 (dt, J = 1.0-1.4, 7.5 Hz, 1 H), 7.51 (dd, J = 1.3-1.4, 2.6 Hz, 1 H), 7.28 (t, J = 7.0-7.9 Hz, 1 H), 7.06-7.02 (ddd, J = 1.0, 2.7, 8.3 Hz, 1 H), 3.86 (s, 3 H), 3.78 (s, 3 H); Ethyl m-anisate: 1H NMR (CDCl3) δ 7.64-7.61 (dt, J = 1.1-1.5, 7.3-7.7 Hz, 1 H), 7.56 (dd, J = 1.4-1.6, 2.5-2.6 Hz, 1 H), 7.34 (t, J = 7.8-8.0 Hz, 1H), 7.11-7.07 (ddd, J = 1.0, 2.7, 8.2-8.3 Hz, 1 H), 4.37 (q, J = 7.1-7.2 Hz, 2 H), 3.85 (s, 3 H), 1.39 (t, J = 7.1-7.2 Hz, 3 H); Methyl p-bromobenzoate: 1H NMR (CDCl3) δ 7.88 (d, J = 8.7 Hz, 2 H), 7.56 (d, J = 8.7 Hz, 2 H), 3.90 (s, 3 H); Methyl m-nitrobenzoate: 1H NMR (CDCl3) δ 8.84 (s, 1 H), 8.42-8.34 (m, 2 H), 7.65 (t, J = 8.0 Hz, 1 H), 3.98 (s, 3 H).
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