1,1-Dimethylethyl 2-(1-methylethyl)hydrazinecarboxylate

Alternatively, tert-Butyl 2-(propan-2-ylidene)hydrazinecarboxylate 2 (0.51 g, 3.0 mmol) was dissolved in 20 mL of THF, treated with NaBCN (0.19 g, 3.0 mmol) and a few mg of bromocresol green, followed by a solution of p-toluenesulfonic acid (0.57 g, 3.0 mmol) in 1.5 mL of THF which was added dropwise over approximately 1 h to maintain the reaction pH between 3.5-5.0. After stirring at room temperature for an additional hour, the solvent was removed by rotary evaporation, and the residue was partitioned between EtOAc (30 mL) and brine. The organic phase was extracted with sat. NaHCC>3, 20 mL and brine, evaporated to a residue and dissolved in 10 mL of ethanol. The ethanolic solution was treated with 3.6 mL of 1M NaOH solution (3.6 mmol) and left to stir at rt for 30 min. The solvent was removed by rotary evaporation and the residue was taken up into ethyl acetate and extracted with water. The organic layer was evaporated under reduced pressure and the residue was purified by column chromatography using 5 percent MeOH in DCM as eluent to collect tert-butyl 2- isopropylhydrazinecarboxylate 3 (0.4 g, 77 percent yield): mp = 47-49 °C; Rf = 0.44 (5 percent MeOH in DCM); IH NMR 300 MHz (CDC13) d 6.03 (s, N-H, IH), 3.92 (s, N-H, IH), 3.14 (m, IH), 1.46 (s, 9H), 1.02 (d, 6H, J = 6 Hz); 13C NMR 300 MHz (CDC13) d 157.2, 80.8, 51.2, 28.7, 21.0.To a solution of isopropylidine hydrazine (2.94 g, 17.1 MMOL) in MEOH at rt under argon was added 5percent PT/C (290 mg). Hydrogen gas was bubbled through the black suspension for 15 min and then the reaction was left under an atmosphere of hydrogen for 1.5 h. After this time, the suspension was filtered and the collected solids were washed with ADDITIONAL MEOH. The combined filtrate and washings were concentrated under reduced pressure. The crude material that remained was then redissolved in EtOAc and washed with sat. NaHCO3. The organic layer was separated, washed with sat. NaCI, dried (MGS04), filtered and concentrated under reduced pressure. Purification by chromatography on silica eluting with 50percent EtOAc/hexanes gave the title compound as colourless crystals (2.08 g, 70percent). 1 H- NMR; δ (CDCI3), 6.34 (1H, s NHBoc), 3.50 (1H, br, NH) 3.13 (1H, sept, J=6.5Hz, CH (CH3) 2), 1.46 (9H, s, (CH3) 3), 1.02 (6H, d, J=6.5Hz, (CH3) 2CH). LRMS: +ve ion: 197 [M+23], 175 [M+1], 161.The title compound can be prepared by the method of Dutta et ( J . C:S Perkin /1975, 1712-1720) Or from the following method: A mixture of 13.2 g (0.1 mol) of t-butyl carbazate and 6 g (0.103 mol) of acetone and 12.58 g (0.1 mol) of anhydrous magnesium sulfate in 100 ml of dichloromethane was stirred at room temperature for 12 hours. After removal of the desiccant by filtration, the filtrate was evaporated under reduced pressure and crystallized from cyclohexane to give 16.9 g of the corresponding hydrazone having a melting point of 104-105 ° C. intoo a suspension solution of 2.04 g (0.094 mol) of lithium borohydride in 100 ml of anhydrous tetrahydrofuran was added 12 ml (0.094 mol) of trimethylchlorosilane in a greenhouse under a nitrogen atmosphere. After 30 minutes at room temperature the 13.45 g (0.078 mol) of hydrazone was slowly added and stirring was continued for 2 hours. Then, 50 ml of methanol was carefully added and the mixture was evaporated to dryness under reduced pressure. The residue was partitioned between ether (150 ml) and water (50 ml). The organic phase was dried over anhydrous magnesium sulfate and filtered, the hydrogen chloride was dried through the filtrate and the resulting white solid was removed by filtration then washed with a portion of fresh ether and dried to give the Hydrochloric acid of the title compound(10.5g).then it was converted to its free base form through partitioning between hexane (150 ml) and 20percent aqueous potassium hydroxide solution to give 8.3 g (61percent) of product.To a solution of tert-butyl 2-(propan-2-ylidene)hydrazine-1-carboxylate (3.90 g, 22.7 mmol) in THF (22 mL) and MeOH (22 mL) was added NaBH(OAc)

Molecular Weight:174.24
XLogP3:1.5
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:4
Exact Mass:174.136827821
Monoisotopic Mass:174.136827821
Topological Polar Surface Area:50.4
Heavy Atom Count:12
Complexity:150
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes