Reaction Steps
A suspension of phosphorus pentachloride (4.71 g., 22.5 mmole) in methylene dichloride (35 ml.) was warmed until most of the phosphorus pentachloride had dissolved. A solution of pyridine in methylene dichloride (18.2 ml., as a 10% v:v solution, ca 22.5 mmole pyridine) was added, and the white suspension was warmed to 23° for 10 minutes, then cooled to 0°. A solution of diphenylmethyl 7β-(2-thienylacetamido)-3-vinylceph-3-em-4-carboxylate (5.16 g., 10 mmole) in methylene dichloride (70 ml.), cooled to 0°, was added and the mixture stirred for 20 minutes. The solution was run into a vigorously stirred mixture of methanol (10 ml.) in methylene dichloride 50 ml.) and the resulting solution washed with aqueous sodium bicarbonate and water, and dried and evaporated in vacuo. The residual gum, in a small volume of chloroform, was run onto a column (7 × 4 cm.) of Kieselgel (0.02 to 0.5 mm.), and the column eluted with chloroform (2 × 100 ml.), then chloroform: ethyl acetate = 1:1 (3 × 100 ml.). The first chloroform fraction and the last chloroform : ethyl acetate fraction were discarded and the other fractions combined and evaporated in vacuo. The residue was triturated with ether to give the amine (2.7 g., 69%) as small needles, m.p. 157° -160° (decomp), [α]D - 155.4° (CHCl3 9, λmax. 296.5 nm. (ε, 12,400), νmax. (CHBr3) 3460 and 3390 (NH), 1780 (β-lactam), 1730 (CO2R) and 910 cm.-1 (CH=CH2), τ (CDCl3) 2.65 (Ph), 3.02 (CH Ph2), 3.09 (CH=CH2, dd, J 11 and 18 Hz.), 4.64 and 4.82 (CH=CH2, two d, J 18 and 11 Hz. resp.), 5.09 (C(7) -H, d, J 5 Hz.), 5.32 (C(6) -H, d, J 5 Hz.), 6.35 and 6.85 (C(2) -CH2, Ab-q J 18 Hz), and 8.21 (NH2); (DMSO-d6) 2.60 (Ph), 3.03 (CH Ph2), 3.28 (CH = CH2, dd J 11 and 17 Hz.), 4.40 and 4.76 (CH=CH2, two d, J 17 and 11 Hz. resp.), 4.91 (C(7) -H, d, J 5 Hz.), 5.12 (C(6) -H, d, J 5 Hz), 6.09 and 6.45 (C(2) -CH2, AB-q J 18 Hz.) and 7.62 (NH2) (Found : C, 66.2; H, 5.1; N, 6.8; S, 8.1. C22H20N2O3S requires C, 67.3;, H, 5.15; N, 7.15; S, 8.2%).
