Sulfuric Acid → HCID 68126061, compound

Participants

Reaction Steps

A mixture of 4 drops of conc, sulfuric acid in 60 ml. N,N-dimethylacetamide and 80 ml. of benzene was dried azeotropically for 30 minutes. p-Methoxybenzyl 6-phthalimido-2,2-dimethylpenam-3-carboxylate-1-oxide (5.0 g., 10 mmol) was then added. The reaction mixture was refluxed for 30 minutes, cooled and evaporated to near dryness. Ethyl acetate (150 ml.) was added to the product, and the resulting solution was evaporated in vacuo to dryness. A crystalline product formed during evaporation of the solvent. The product was then slurried with 50 ml. of ethyl acetate. Filtration gave 3.1 grams (62 percent) of p-methoxybenzyl 7-phthalimido-3α-methyl-3β-hydroxycepham-4-carboxylate as colorless crystals, mp 216°-217°: nmr (CDCl3) 76 (3, s, 3-CH3), 149 and 205 (2, ABq, J=14 Hz, 2-CH2), 230 (3, s, OCH3), 274 (1, s, 4-H), 300 (1, broad s, OH), 309 (2, s, ester CH2), 324 (1, d, J=4.5 Hz, azetidinone H), 335 (1, d, J=4.5 Hz, azetidinone H), 426 (4, q, p-CH3OC6H4ArH) and 469 Hz (4, m, phthalimido H); ir (mull) 3460 (OH), 1725 (ester C=O), 1739 and 1781 (phthalimido C=O) and 1802 cm-1 (azetidinone C=O, shoulder).

Provenance & Evidence