Acetone → N-Carbobenzyloxy-N'-isopropylhydrazine
Reaction equation
[CH3:1][C:2]([CH3:4])=O.[C:5]([NH:15][NH2:16])([O:7][CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)=[O:6].C([BH3-])#N.[Na+]>C(O)C>[C:5]([NH:15][NH:16][CH:2]([CH3:4])[CH3:1])([O:7][CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)=[O:6]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
Acetone (0.377 g; 0.477 ml; 6.50 mmol) was added to a solution of carbobenzyloxyhydrazine (1.00 g; 6.02 mmol) in absolute ethanol (6 ml). After one hour, the solution was concentrated to dryness and then ethanol (5 ml) and sodium cyanoborohydride (0.19 g; 3.0 mmol) were added. The mixture was stirred for 18 hours and then evaporated to a thick syrup. Hydrochloric acid (0.50 N; 5 ml) and ether (50 ml) were added and the two-phase mixture was stirred for one hour. The aqueous layer was neutralized by addition of solid NaHCO3 and extracted with ether (2×25 ml). The combined ether portions were washed with water and brine and dried (MgSO4) Removal of solvent gave a solid which was recrystallized from hexanes - ether, giving pure hydrazide 4 (1.09 g; 5.25 mmol; 87%), mp 61°-62°. TLC (silica gel; CH2Cl2 --CH3OH; 20:1) Rf=0.5. MS m/e 208 (M+). Analysis: Calculated for C11H16N2O2 : (C, 63.44; H, 7.44; N, 13.45). Found: C, 63.22; H, 7.67; N, 13.71; NMR (CDCl3);δ0.97 (6H,d,J=6); 3.15 (1H, septet, J=6); 3.8-4.6(1H, broad); 5.13(2H,S); 6.2-7.0(1H, broad); 7.33 (5H,S); IR(CHCl3) 3500, 1720 cm-1.
Workup
- concentrationthe solution was concentrated to dryness
- customevaporated to a thick syrup
- additionHydrochloric acid (0.50 N; 5 ml) and ether (50 ml) were added
- stirringthe two-phase mixture was stirred for one hour
- additionThe aqueous layer was neutralized by addition of solid NaHCO3
- extractionextracted with ether (2×25 ml)
- washThe combined ether portions were washed with water and brine
- customdried
- custom(MgSO4) Removal of solvent
- customgave a solid which
- customwas recrystallized from hexanes - ether
Sources & evidence
- ORD record
- ord-5fad485d070f4a9cbef943c916170cca
- Source dataset
- uspto-grants-1987_01
- Patent number
- US04634715
Reaction notes
Loading…