反応 #1994303

反応方程式

(E)-6-(4-chloro-2-fluoro-3-methoxyphenyl)-2,4-dioxo-hex-5-enoic acid ethyl ester

(E)-6-(4-Chloro-2-fluoro-3-methoxyphenyl)-2,4-dioxo-hex-5-enoic acid ethyl ester

ammonium acetate

→

(2Z,5E)-2-amino-6-(4-chloro-2-fluoro-3-methoxyphenyl)-4-oxo-hexa-2,5-dienoic acid ethyl ester

収率 102.2%

溶媒

EtOH

反応条件

実験手順

Using the procedure of Example 4, (E)-6-(4-chloro-2-fluoro-3-methoxyphenyl)-2,4-dioxo-hex-5-enoic acid ethyl ester (5; 37.8 g, 0.115 mol) and ammonium acetate (15.4 g, 0.2 mol) were allowed to react in EtOH (200 mL) to yield (2Z,5E)-2-amino-6-(4-chloro-2-fluoro-3-methoxyphenyl)-4-oxo-hexa-2,5-dienoic acid ethyl ester (10; 38.5 g, 92%, 90% pure by 1H NMR spectroscopy) as a dark orange solid. Treatment with silica gel (50 g) followed by eluting with 40% EtOAc/hexanes (400 mL) gave a yellow solid (25.3 g, 67%): mp 103-104° C.; 1H NMR (400 MHz, CDCl3) δ 9.44 (br s, 1H), 7.63 (d, J=16.1 Hz, 1H), 7.23 (dd, J=8.6, 7.0 Hz, 1H), 7.16 (dd, J=8.6, 1.6 Hz, 1H), 6.87 (d, J=16.1 Hz, 1H), 6.15 (s, 1H), 6.04 (br s, 1H), 4.37 (q, J=7.1 Hz, 2H), 3.98 (d, J=1.2 Hz, 3H), 1.40 (t, J=7.1 Hz, 3H); HRMS-ESI (m/z): calcd for C15H15ClFNO4, 327.067. found, 327.068.

出典