Reaktion #345833

Reaktionsgleichung

t-butyl 3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate

pyrid-4-ylacetyl chloride hydrochloride

propylene oxide

→

ester

t-Butyl-3-acetoxymethyl-7β-(pyrid-4-ylacetamido)ceph-3-em-4-carboxylate

Lösungsmittel

ethyl acetate

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled in ice
2. 2
   workup.STIRRINGThe mixture was stirred at 20° for 20 hours
3. 3
   Waschenwashed with saturated sodium bicarbonate solution
4. 4
   Extraktionextracted with 2 N hydrochloric acid
5. 5
   ExtraktionThe aqueous extract
6. 6
   Waschenwas washed with ethyl acetate
7. 7
   Extraktionextracted with ethyl acetate
8. 8
   WaschenThe extract was washed with water
9. 9
   Trocknendried over magnesium sulphate
10. 10
    Sonstigeevaporated to small bulk whereupon crystallisation
11. 11
    WaschenThe crystalline solid was washed well with petroleum spirit (bp. 40°-60°)
12. 12
    Sonstigedried

Vorschrift

A suspension of pyrid-4-ylacetyl chloride hydrochloride (6.0 g.) in ethyl acetate (50 ml) containing propylene oxide (12 ml.) was stirred, cooled in ice and treated dropwise with a solution of t-butyl 3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate (5.0 g.) in ethyl acetate (50 ml.). The mixture was stirred at 20° for 20 hours and then washed with saturated sodium bicarbonate solution and extracted with 2 N hydrochloric acid. The aqueous extract was washed with ethyl acetate, neutralised with saturated sodium bicarbonate solution and extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulphate and evaporated to small bulk whereupon crystallisation began. The crystalline solid was washed well with petroleum spirit (bp. 40°-60°) and dried to give the title ester as a buff coloured powder (5.4 g., 80% based on amine). A portion (250 mg.) was recrystallised from ethyl acetate as white needles (170 mg.), [α]D +94° (c 0.9, DMSO) λmax. (EtOH) 256.5 nm (ε 9,900), νmax. (CHBr3) 3412 (NH), 1784 (β-lactam), 1736 (OAc), 1722 (CO2R), 1690 and 1512 cm.-1 (CONH), τ (d6 -DMSO) 0.81 (d, J 8 Hz; NH), 1.47 and 2.68 (2d, J 5 Hz; aromatic protons), 4.27 (q, J 8 and 5 Hz; C-7H), 4.85 (d, J 5 Hz; C-6 H), 5.01 and 5.36 (2d, J 13 Hz; C-3CH2), 6.38 (s; CH2CONH), 6.39 (s; C-2H2), 7.96 (s; OCOCH3), and 8.50 (s; C(CH3)3).

Quelle