Methanol → Thionyl Chloride

Methanol (400 mL) was cooled to 0° C. and thionyl chloride (217 mL, 3.0 moles, 20 eq) was added dropwise under argon. After addition was completed, the solution was warmed to RT for 20 min. 2(S),3-Diaminopropanoic acid 2-1 (20 g, 0.143 mole) (Schweizerhall Chemicals) was crushed to a fine powder and added to the solution. The reaction was heated to reflux for 48 h, at which time TLC showed a small amount of starting material remaining. An additional portion of methanol (100 mL) and thionyl chloride (72 mL) was prepared as before and added to the reaction at RT; the reaction was then stirred overnight at RT. The reaction was worked up by removal of solvent at 40° C. in vacuo to give 2-2 as foam. Rf 0.72 (9:1:1 EtOH/H2O/NH4OH). 1H NMR (400 MHz, D2O) δ4.55 (dd, J=5.4 8.2 Hz, 1H), 3.92 (s, 3H), 3.64 (dd, J=8.2, 13.8 Hz, 1H), 3.55 (dd, J=5.4, 13.8 Hz, 1H).

1. additionAfter addition
2. additionadded to the solution
3. temperatureThe reaction was heated
4. temperatureto reflux for 48 h, at which time TLC
5. additionadded to the reaction at RT
6. customThe reaction was worked up by removal of solvent at 40° C. in vacuo

ORD record

ord-1c0106c52e924777920c0772a1de0fbe

Source dataset

uspto-grants-1997_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05646000