Org Prep Daily

November 13, 2006

N-TBS-propiolactam and N-TBS-pyrrolidone

Filed under: procedures — milkshake @ 2:40 pm


DBU 11.7mL (78mmol) was added to a slurry of propiolactam 4.902g (68.9mmol, Aldrich) and TBS-Cl 11.43g (75.9mmol) in anh DMF (30mL) with cooling on ambient water bath. The reaction was stirred at RT for 3 hours at ambient bath and the obtained heterogennous mixture was quenched by addition of saturated aqueous ammonium chloride 200mL. The mixture was extracted with ether twice (2x250mL). The organic extracts were washed with water (250mL), combined, dried (MgSO4) and evaporated. The residue was distilled on highvac (0.5Torr). After a small front fraction (1.5g), the pure product distilled at 58-61C/0.5Torr. Y=10.823g (84.5%) of a clear liquid.

1H(CDCl3, 400MHz): 3.154(br t, 4.3Hz, 2H), 3.028(br t, 4.4Hz, 2H), 0.914(s, 9H), 0.191(s, 6H); 13C(CDCl3,100MHz):172.70, 39.18, 36.87, 26.23(3C), 18.75, -5.88 (2C)


Analogous procedure: DBU 16.5mL (110mmol) was added to a slurry of 2-pyrrolidone 8.511g (100mmol, Aldrich) and TBS-Cl 15.073g (100mmol) in anh DMF (40mL) with cooling on ambient water bath and the mixture was then stirred for 1 hour at RT. Y=17.641g (88.5%) of a colorless liquid, b.p. 69-71C/0.5Torr

1H(CDCl3, 400MHz): 3.354(t, 6.6Hz, 2H), 2.292(t, 8.2Hz, 2H), 1.990(m, 2H), 0.911(s, 9H), 0.228(s, 6H); 13C(CDCl3, 100MHz): 183.14, 48.16, 33.10, 26.85(3C), 22.14, 19.63,-4.88(2C)

Leave a Comment »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Blog at

%d bloggers like this: