Ammonia → 5-Oxo-pyrrolidine-3-carboxylic acid methyl ester

To a solution of 2-methylene-succinic acid dimethyl ester (158 g, 1 mol, 1 eq) in MeOH (150-160 mL) was added dropwise anhydrous liquid ammonia (17 g, 1 mol, 1 eq). The mixture was stirred at room temperature for 1.5-2 h, keeping the outlet of the flask connected with a small mercury trap (1-2 cm Hg), and left to stand overnight. Most part of MeOH was evaporated on a water bath and then residual MeOH was evaporated in vacuo until the mixture transformed into a semisolid mass. This mass was distilled in vacuo. Starting compound was distilled (bp 60-70° C. at 1 mm Hg) followed by distillation of title compound (bp 140-150° C. at ˜1 mm Hg) as colorless liquid, which crystallized very fast (72 g, 0.5 mol, 50%).

1. customconnected with a small mercury trap
2. wait(1-2 cm Hg), and left
3. waitto stand overnight
4. customMost part of MeOH was evaporated on a water bath
5. customresidual MeOH was evaporated in vacuo until the mixture
6. distillationThis mass was distilled in vacuo
7. distillationStarting compound was distilled (bp 60-70° C. at 1 mm Hg)
8. distillationfollowed by distillation of title compound (bp 140-150° C. at ˜1 mm Hg) as colorless liquid, which
9. customcrystallized very fast (72 g, 0.5 mol, 50%)

ORD record

ord-f2ecf1a7b6264647968345c65733e2b0

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08741934B2