反应详情

3-Hydroxymethyl-7β-(2'-thienylacetamido)ceph-3-em-4-carboxylic acid (500 mg.) was dissolved in dry tetrahydrofuran and treated with a solution of diphenyldiazomethane (300 mg., 1.1 equiv.) in petrol. Nitrogen was evolved slowly, and after 21/2 hours the solution was evaporated, the residue dissolved in ethyl acetate, and the solution was washed with bicarbonate solution and re-evaporated. This gave a gum which solidified on trituration with ether (0.5 g.). A sample was recrystallised from methanol, m.p. 164°, [α]D23 = + 25° (c, 1.0, dioxan), +22° (c 1.0, tetrahydrofuran). λλmax. ethanol 234 nm. E1 cm1% = 255, (ε = 13,300), 259 nm. E1cm1% = 151 (ε 7,850), νmax. (bromoform) 3420 (OH), 3280 (NH), 1750 (β-lactam), 1722 cm-1 (COOR). (Found, C, 62.2; H, 4.5; N, 5.4; S, 12.1. C27H24N2O5S2 requires C, 62.3; H, 4.7; N, 5.4; S, 12.3%) RF = 0.83 (Kieselgel G plates; ethyl acetate:benzene=1:2).

1. customafter 21/2 hours the solution was evaporated
2. dissolutionthe residue dissolved in ethyl acetate
3. washthe solution was washed with bicarbonate solution
4. customre-evaporated
5. customThis gave a gum which
6. customA sample was recrystallised from methanol, m.p. 164°, [α]D23 = + 25° (c, 1.0, dioxan), +22° (c 1.0, tetrahydrofuran)