Sodium o-formylbenzenesulfonate → (1r,5r,6s)-2-{[3-Ethoxycarbonyl-5-(1-ethyl-propoxy)-6-hydroxy-cyclohex-3-enylimino]-methyl}-benzenesulfonic acid sodium salt

Participants

Reaction Steps

To a stirred suspension of 27.1 g (100 mmol) (3R,4S,5R)-5-amino-3-(1-ethylpropoxy)-4-hydroxycyclohexene-1-carboxylic acid ethyl ester and 20.8 g (100 mmol) 2-formylbenzenesulfonic acid sodium salt in 270 ml ethanol was heated to reflux under argon for 2 hours. The brown, turbid reaction mixture was evaporated in a rotary evaporator and the residue was treated twice with 135 ml of ethyl acetate and evaporated in a rotary evaporator at 50° C. to dryness to yield 45.88 g (99%) of (1R,5R,6S)-2-{[3-ethoxycarbonyl-5-(1-ethyl-propoxy)-6-hydroxy-cyclohex-3-enylimino]-methyl}-benzenesulfonic acid sodium salt as a yellow amorphous solid. IR (film): 3417, 2924, 2726, 1714, 1638, 1464, 1378, 1237, 1091, 970 cm−1; MS (ISP-MS): 438.3 (M+−Na) m/z.

Provenance & Evidence