ZP 1609 Hydrochloride synthesis

Yield: 93.8%

Reaction Conditions:

with hydrogenchloride in acetone at 50; for 0.25 h;Product distribution / selectivity;

Steps:

2.4
To a slurry of (2S₁ 4R)-4-benzamido-1-(2-(ferf-butoxycarbonyl- amino)acetyl)pyrrolidine-2-carboxylic acid (650.2 g) in acetone (4.1 L) was added cone, hydrochloric acid (322 g). The reaction mixture was heated to 50⁰C over 15 min and stirred at 5O⁰C. The reaction was monitored for completion by HPLC. Water (520 g) was added. The mixture was heated to reflux to dissolve the solid coating. The resulting clear solution was cooled to 40⁰C. Acetone (7.0 L) was added over 15 min while temperature was maintained at 30-40⁰C. The mixture was cooled to room temperature over 30 min, and stirred until a white slurry was formed. Additional acetone (7.0 L) was added over 10 min. The mixture was stirred overnight at about 22-24°C. The precipitated solids were filtered through a Buchner funnel lined with polypropylene and washed with acetone (2 x 2 L)₁ was dried on the funnel to give 530 g (93.8%) of product as a monohydrate. LC area purity was 99.7%. ¹H NMR (DMSO-Cf₆₁ δ, ppm, for two conformers): 8.77 (d, J = 7 Hz₁ 0.8 H), 8.71 (d, J = 7 Hz₁ 0.2 H)₁ 8.68-7.95 (br, 2 H)₁ 7.92-7.83 (m, 2 H)₁ 7.59-7.43 (m, 3 H)₁ 4.87-4.79 (m, 0.2 H)₁ 4.68-4.54 (m, 0.8 H)₁ 4.54- 4.44 (m, 1 H)₁ 4.0 - 3.47 (m, 4 H), 2.47-2.12 (m, 2 H). HRMS calc. for C₁₄H₁₈N₃O₄ (M+H): 292.1297, found: 292.1294.

References:

WYETH WO2008/79266, 2008, A2 Location in patent:Page/Page column 65