Hydrochloric Acid → HCID 15730235, compound

Participants

Reaction Steps

(i) 7β-Formamido-3-methylthiomethylceph-3-em-4-carboxylic acid (2.88g) was dissolved in methanol (25 ml.) and the stirred solution was treated with concentrated hydrochloric acid (4.0 ml.). After 1.5 hr. at room temperature the solution was diluted with water (80 ml.) and washed with ethyl acetate (2 × 30 ml.) and ether (2 × 20 ml.), rotary evaporated to remove residual ether, and the pH adjusted to 3.5 with 0.880-ammonia. The precipitate was collected after overnight refrigeration, washed with water (2 × 10 ml), methanol (2 × 10 ml.) and ether (3 × 20 ml.), then dried giving 7β-amino-3-methylthiomethylceph-3-em-4-carboxylic acid as a colourless powder (1.41 g.), m.p. 222°-225° (decomp.), Rf 0.60 (System 2), TLC Rf 0.15, moves 2.0 cm. towards the cathode on electrophoresis at pH 1.9 (3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylic acid moves 1.85 cm. under identical conditions), λmax (pH6 buffer) 266 nm. (ε 9,590), νmax. (Nujol) 1804 (β-lactam), 1536 cm.-1 (carboxylate), τ(D2O with NaHCO3) 4.53 (~0.5-proton doublet, J 4.5 Hz.; C-7 H), 4.88 (1-proton doublet, J 4.5 Hz.; C-6 H), 5.21 (~0.5-proton doublet, J 4.5 Hz.; C-7 H), 6.14, 6.63 [two 1-proton doublets (branches of a quartet), J 18 Hz.; C-2 H2 ], 6.21, 6.68 [two 1-proton doublets (branches of a quartet), J 14 Hz.; C-3 CH2 ], 7.95 (3-proton singlet; SCH3) [Found: C, 41.2; H, 4.6; N, 10.2; S, 23.6. C9H12N2O3S (260) requires C, 41.5; H, 4.6; N, 10.8; S, 24.6%].

Provenance & Evidence