Butanoic acid, 2-amino-, methyl ester, hydrochloride (1:1)

White Solid

10.0 g (49.2 mmol) BOC-L-2-aminobutyric acid was dissolved in 100 ml of methanol and 6 ml (82.2 mmol) thionyl chloride were added dropwise at 0° C. The solution was stirred for 14 h at ambient temperature and then evaporated down in vacuo.Yield: 7.6 g (101percent) 2-a.ES-MS (M+H)To a solution of (S)-2-aminobutanoic acid (5.0 g, 48 mmol) in methanol (50 ml.) at -20 °C was added dropwise thionyl chloride (3.9 ml_, 53 mmol) and the mixture allowed to warm to ambient temperature and stirred overnight. The reaction mixture was concentrated in vacuo, and then the residue was washed with diethyl ether, filtered and dried under vacuum to afford the title compound as a solid (6.2 g). The crude product was used without further purification in subsequent reactions. LCMS (Method G): 0.16 min, 1 19 [M+H]Adding 18 kg (174.55 mol) of L-2-aminobutyric acid to a 500 L reactor, Anhydrous methanol 90L (5v/w), 27.0 kg (226.9 mol) of thionyl chloride was added dropwise at 25 ° C.About 1 hour, Control temperature does not exceed 40 ° C, The solution changed from turbid to clear.After the addition is completed, Warming reflux reaction for 2h, TLC test (spotting 1 time, developing agent: dichloromethane / methanol = 2 / 1 plus 3 drops of three BAmine, RfSM1-1=0.3, RfSM1-2=0.9), After the reaction, the solvent was distilled off under reduced pressure at 50 ° C, and the residual solvent was dried using 9 L (0.5 v/w) acetone; the dry residue was added to 72 L (4 v/w) acetone at 10 ° C for 1 h, filtered, and 9 L (0.5 v/w) acetone was used. Rinse. Filter cake minus 35 ° CDrying to constant weight gave 18769.3 g of a white solid (SM1-2), yield 70percent.To a solution of (S)-2-aminobutanoic acid (5.0 g, 48 mmol) in methanol (50 ml.) at -20 °C was added dropwise thionyl chloride (3.9 ml_, 53 mmol) and the mixture allowed to warm to ambient temperature and stirred overnight. The reaction mixture was concentrated in vacuo, and then the residue was washed with diethyl ether, filtered and dried under vacuum to afford the title compound as a solid (6.2 g). The crude product was used without further purification in subsequent reactions. LCMS (Method G): 0.16 min, 1 19 [M+H]10.0 g (49.2 mmol) BOC-L-2-aminobutyric acid was dissolved in 100 ml of methanol and 6 ml (82.2 mmol) thionyl chloride were added dropwise at 0° C. The solution was stirred for 14 h at ambient temperature and then evaporated down in vacuo.Yield: 7.6 g (101percent) 2-a.ES-MS (M+H)A suspension of methyl (2S)-2-aminobutanoate hydrochloride (15.0 g, 98 mmol) in 300 mL of dichloromethane was chilled in an ice bath and then triethylamine (40.9 mL, 294 mmol) and di-tert-butyl dicarbonate (21.3 g, 98 mmol) were added. The ice bath was removed and the reaction was stirred for 24 hours at ambient temperature. A 5% solution of NaLLPCL was then added to the reaction mixture and the layers were separated. The organic portion was washed successively with a saturated aqueous sodium bicarbonate solution, a 10% aqueous citric acid solution (2x), water and brine. The organic portion was dried over NaiSCL. filtered and concentrated to give 19.5 g of methyl (2S)-2-[(tert-butoxycarbonyl)amino]butanoate as a colorless oil.General procedure: A solution of azidobenzaldehydes 1 (0.3 mmol), amino esters 2 (0.36 mmol) and maleimides 3 (0.33 mmol) with Et3N (0.45 mmol) in EtOH (2.0 mL) heated under microwave irradiation at 125 C for 30 minGeneral procedure: Dimethylformamide (1 drop) was added to a solution of palmitoleic acid (S7) (0.100 g, 0.393 mmol, 1 equiv) in CH2Cl2 (2 mL). Oxalyl chloride (0.074 g, 0.586 mmol, 1.5equiv) in CH2Cl2 (1 mL) was added dropwise to the solution at 0 C. The resultingsolution was left to stir at room temperature for 3 h until gas formation ended and thesolvent was removed. A mixture of valine methyl ester hydrochloride (0.066 g, 0.393mmol, 1 equiv), CH2Cl2 (0.65 mL) and water (0.65 mL) was prepared. K2CO3 (0.163g, 1.179 mmol, 3 equiv) was added to the resulting solution at 0 C. The mixture wasstirred at 0 C for 5 min before the freshly synthesized (Z)-hexadec-9-enoyl chloride in CH2Cl2 (0.65 mL) was added. After stirring at room temperature for 16 h themixture was extracted with CH2Cl2 (3 × 10 mL), dried with MgSO4, and concentratedin vacuo. Flash column chromatography (pentane/diethyl ether 1:1) provided the purecompound 9 as colorless oil (0.120 g, 0.326 mmol, 83%).General procedure: Dimethylformamide (1 drop) was added to a solution of palmitoleic acid (S7) (0.100 g, 0.393 mmol, 1 equiv) in CH2Cl2 (2 mL). Oxalyl chloride (0.074 g, 0.586 mmol, 1.5equiv) in CH2Cl2 (1 mL) was added dropwise to the solution at 0 C. The resultingsolution was left to stir at room temperature for 3 h until gas formation ended and thesolvent was removed. A mixture of valine methyl ester hydrochloride (0.066 g, 0.393mmol, 1 equiv), CH2Cl2 (0.65 mL) and water (0.65 mL) was prepared. K2CO3 (0.163g, 1.179 mmol, 3 equiv) was added to the resulting solution at 0 C. The mixture wasstirred at 0 C for 5 min before the freshly synthesized (Z)-hexadec-9-enoyl chloride in CH2Cl2 (0.65 mL) was added. After stirring at room temperature for 16 h themixture was extracted with CH2Cl2 (3 × 10 mL), dried with MgSO4, and concentratedin vacuo. Flash column chromatography (pentane/diethyl ether 1:1) provided the purecompound 9 as colorless oil (0.120 g, 0.326 mmol, 83%).

Intermediate in the preparation of Ergonovine (E597800) derivatives.

Molecular Weight:153.61
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:3
Exact Mass:153.0556563
Monoisotopic Mass:153.0556563
Topological Polar Surface Area:52.3
Heavy Atom Count:9
Complexity:82.5
Undefined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:2
Compound Is Canonicalized:Yes