Sodium Hydroxide → HCID 59608157, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-((1S,3R)-1-biphenyl-4-ylmethyl-3-ethoxycarbonyl-butylcarbamoyl)-thiophene-2-carboxylic acid (Example 26: 115 mg, 0.247 mmol) in THF (1 mL) at 0° C. is added diisopropylethylamine (63.8 mg, 0.494 mmol) followed by dropwise addition of a solution of isobutyl chloroformate (33.7 mg, 0.247 mmol) in THF (0.1 mL). The mixture is stirred at 0° C. for 30 minutes then ammonium hydroxide (0.3 mL of 14.8 M solution) is added. The mixture is allowed to warm to room temperature then aqueous 1M HCl (3 mL) is added. Most of the THF is removed under reduced pressure and the mixture is extracted with ethyl acetate. The organic phase is dried over sodium sulfate and the solvent is removed under reduced pressure to give (2R,4S)-5-biphenyl-4-yl-4-[(5-carbamoyl-thiophene-2-carbonyl)-amino]-2-methyl-pentanoic acid ethyl ester. MS 465.3 (M+1). Next, to a solution of (2R,4S)-5-biphenyl-4-yl-4-[(5-carbamoyl-thiophene-2-carbonyl)-amino]-2-methyl-pentanoic acid ethyl ester (115 mg, 0.248 mmol) in ethanol (8 mL) is added aqueous 1M NaOH (0.866 mL, 0.866 mmol) and the mixture is stirred at 50° C. for 3.5 hours. The ethanol is removed under reduced pressure and water is added to the residue. The resulting solution is acidified with aqueous 1M HCl and the resulting precipitate is filtered and washed with water. The solid is purified by preparative HPLC using 50% MeCN/water to elute the product. The appropriate fractions are lyophilized to give (2R,4S)-5-biphenyl-4-yl-4-[(5-carbamoyl-thiophene-2-carbonyl)-amino]-2-methyl-pentanoic acid. MS 437.2 (M+1); 1H-NMR (400 MHz, DMSO-d6); δ ppm 1.09 (d, J=7.20 Hz, 3H), 1.57 (m, 1H), 1.88 (m, 1H), 2.46 (m, 1H), 2.84 (m, 2H), 4.18 (m, 1H), 7.28 (d, J=8.21 Hz, 1H), 7.33 (t, 1H), 7.44 (t, 1H), 7.57 (d, J=8.21 Hz, 2H), 7.64 (d, J=7.33, 2H), 7.69 (m, 2H), 8.06 (s, 1H), 8.38 (d, J=8.59 Hz, 1H), 12.07 (s, broad, 1H).

Provenance & Evidence