HCID 131710425, compound → HCID 131710424, compound

Participants

Reaction Steps

A solution of diphenylmethyl (6R,7R,2'R and S)-7-(2'-hydroxyphenylacetamido)-3-methylceph-3-em-4-carboxylate (529mg, 1.03mmole) in trifluoroacetic acid (1.3ml) was stirred at +20 to +25° for 10mins, and then evaporated. The residual oil was dissolved in ethyl acetate (50ml) and washed with 3%-sodium bicarbonate solution (3×15ml). The combined aqueous layers were washed with ethyl acetate (3×15ml), then covered with ethyl acetate (50ml) and adjusted to pH2.5. The ethyl acetate layer was combined with the ethyl acetate wash (15ml) of the aqueous layer, dried, and evaporated, leaving the title compound (as a 5:3=S:R-mixture of diastereomers, [nmr]) as a foam containing 1/2 mole-equivalent of ethyl acetate (nmr and microanalysis) and 2mole-equivalents of water (i.r. and microanalysis) (258 mg, 0.60mmole, 58%); λmax 257.5nm, inflexions at 254 and 262.5nm (ε5,870; 5,780 and 5,830 respectively); νmax 3640 (OH, H2O), 3450 (NH), 1784 (azetidin-2-one), 1730 (CO2H) and 1690; and 1510 cm-1 (CONH); τ assignments of minor component (2'R) follow those of the major component (2'S) 1.52 and 1.36 (total 1H, 2d, J 9Hz, NH), 2.40 to 2.73 (5H,m,C6H5), 4.36 and 4.33 (total 1H,2d, J9 and 4.5Hz, C7 -H), 4.90 and 4.83 (total 1H,2S,C6H5CH), 4.93 and 4.98 (total 1H, 2d, J4.5Hz, C6 -H), 6.51(S) and 6.38 and 6.64 (ABq J18Hz) total 2H,C2 -H2), 7.95 (3H,C3 -CH3), and signals at 5.91, 7.98 and 9.78 revealed the presence of 1/2mole-equivalent of ethyl acetate. (Found: C,50.7; H,4.9; N,6.0 and 6.1; S,7.3. C16H16N2O5S. 1/2 CH3CO2C2H5. 2H2O (428.4) requires C,50.4; H,5.6; N,6.5;S,7.5%).

Provenance & Evidence