反应详情

A solution of pyridine (2.4 ml.) in dry tetrahydrofuran (5 ml.) was added to a stirred solution of diphenylmethyl 3-hydroxymethyl-7β-(thien-2-yl)acetamido-ceph-3-em-4-carboxylate (3.12 g) and pivaloyl chloride (7.2 g) in dry tetrahydrofuran (150 ml) at 20°. The solution was stirred at 20° for 16 hours, filtered and concentrated under reduced pressure. The residue was dissolved in ethyl acetate and washed successively with sodium bicarbonate solution, 2 N-hydrochloric acid, sodium bicarbonate solution, water and brine. The dried solution was concentrated under reduced pressure to give a solid residue that was triturated with ether to give the title ester (2.7 g; 75%), [α]D +5.1 (c 1.4, CHCl3), λinflex. (ethanol) 235 (ε14,100), 257 (ε8,300) and 263 nm. (ε8,050), λmax. (CHBr3) 1787 (β-lactam), 1722 (ester), 1680 and 1510 cm.-1 (CONH) τ (CDCl3) values include 8.81 (singlet; C(CH3)3).

1. filtrationfiltered
2. concentrationconcentrated under reduced pressure
3. dissolutionThe residue was dissolved in ethyl acetate
4. washwashed successively with sodium bicarbonate solution, 2 N-hydrochloric acid, sodium bicarbonate solution, water and brine
5. concentrationThe dried solution was concentrated under reduced pressure
6. customto give a solid residue that
7. customwas triturated with ether