Diazomethane → 7-tert.-Butoxycarbonylamino-2-methoxycarbonyl-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene

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Reaction Steps

7-tert.-Butoxycarbonylamino-2-methoxycarbonyl-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-end can be prepared by esterifying 7-tert.-butoxycarbonylamino-2-carboxy-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene (16.7 g) (described in Example 1) with a solution of diazomethane in ether, according to the method of R. B. Morin, et al., J. Amer. Soc., 91(6), 1401 (1969). 7-tert.-Butoxycarbonylamino-2-methoxycarbonyl-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene (13.6 g) is obtained in the form of white crystals (m.p.=148° C.).

Provenance & Evidence