Ethyl chloroformate → HCID 58293770, compound

To a solution of 1-(thiophen-2-yl)butan-2-amine (2.1 g, 13.72 mmol) in methylene chloride (40 mL) was added ethyl glyoxylate (2.80 g, 13.72 mmol) at RT. One drop of acetic acid was added, the mixture stirred at RT for 75 min, and sodium triacetoxyborohydride (4.36 g, 20.58 mmol) was added. The reaction was stirred at RT for 15 hours before quenching the reaction by adding 5 mL of acetic acid. The volatiles were removed under reduced pressure and the residue dissolved in 40 mL THF. Saturated sodium bicarbonate (40 mL) was added carefully, followed by the addition of ethyl chloroformate (2.978 g, 2.624 mL, 27.44 mmol). Solid NaHCO3 was subsequently added portionwise until gas evolution ceased. The reaction was stirred at RT overnight and extracted with EtOAc (2×). The organics were dried over Na2SO4, the volatiles removed under reduced pressure, and there resulting yellow oil purified by silica gel chromatography, using a 0-35% EtOAc/hexanes gradient as eluant, to produce ethyl 2-(ethoxycarbonyl-(1-(thiophen-2-yl)butan-2-yl)amino)acetate (Compound 1035, 3.03 g) as a colorless oil.

1. stirringThe reaction was stirred at RT for 15 hours
2. custombefore quenching
3. customthe reaction
4. customThe volatiles were removed under reduced pressure
5. dissolutionthe residue dissolved in 40 mL THF
6. additionSaturated sodium bicarbonate (40 mL) was added carefully
7. stirringThe reaction was stirred at RT overnight
8. extractionextracted with EtOAc (2×)
9. dry with materialThe organics were dried over Na2SO4
10. customthe volatiles removed under reduced pressure
11. customthere resulting yellow oil
12. custompurified by silica gel chromatography

ORD record

ord-95251c8eb58e467a97650ba5827e6261

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08481524B2