Cephalothin → HCID 70603475, compound

Participants

Reaction Steps

A solution of 3-acetoxymethyl-7β-(2-thienylacetamido)ceph-3-em-4-carboxylic acid (146.5 g.) in pyridine (600 ml.) was treated with acetic anhydride (45 ml.) and the mixture stirred vigorously at 22° for 45 minutes. The material which crystallised out was isolated by filtration washed with pyridine and ethyl acetate, and dried in vacuo to give the pyridinium salt of the title compound (95.15 g., 54.5%). This pyridinium salt was stirred with water (350 ml.) and ethyl acetate (700 ml.) and 2N-hydrochloric acid (ca 120 ml.) added until all the solid had dissolved. The organic phase was separated, washed with water, dried and evaporated in vacuo to give the title compound (77 g.) as a white solid, m.p. 151°-152.5°, [α]D + 480° 5% sodium carbonate), λmax. 235 nm. (ε 15,200), νmax. 3293 (NH), 1746 (β-lactam), 1722 and 2600 (CO2H), 1722 and 1208 (CH2OCOCH3) and 1660 and 1528 cm.-1 (CONH), τ (D2O - sodium bicarbonate) 2.7 and 3.0 (thienyl, 1-proton t and 2-proton d), 3.62 (C(2) -H, broad s), 4.58 (C(7) -H, d, J 4.5 Hz), 4.69 (C(6) -H, d, J 4.5 Hz), 5.18 (C(4) -H, broad s), 6.15 (CH2CONH, s) and 7.9 (-OCOCH3, s) (CH2OAc obscured by H2O band). (Found: C, 48.3; H, 4.1; N, 7.0; S, 16.2. Calc. for C16H16N2O6S2 : C, 48.4; H, 4.05; N, 7.05; S, 16.15%).

Provenance & Evidence