Methylhydrazine → Azaalanyl proline t-butyl ester

Participants

Reaction Steps

A solution of crude carbamoyl chloride 1 (9.35 g) in dry THF (40 ml) was added to an ice-cold solution of methylhydrazine (3.46 g; 4.00 ml; 0.075 mol) and triethylamine (6.33 g; 8.73 ml; 0.063 mol) in dry THF (40 ml). Stirring was continued at room temperature for 18 hours. The reaction mixture was filtered and evaporated, giving a light yellow solid. Recrystallization from hexane - chloroform gave 2 (6.62 g; 0.0272 mol; 68%) as a white solid, mp 89°-92°, TLC (silica gel; CH2CL2 --CH3OH, 10:1) Rf=0.45. MS m/e 243 (M+) Analysis: Calculated for C11H21N3O3 ; C,54.30; H, 8.70; N, 17.27. Found: C, 54.45; H, 8.96; N, 17.29, NMR (CDCl3): δ1.42 (9H,S); 1.7-2.3(4H.S); 3.00 (3H,S); 3.4-3.8(2H,m); 3.8(2H.bs); 4.4(1H.m) 1R(CHCl3): 35-3300, 1730, 1630 cm-1 [α]D =-55.7°±0.5°.

Provenance & Evidence