Sumitomo Chemical Company, Limited

Kaoru Maeshima

Takenari Nakagome

Masataka Fukumura

Kozo Shimago

Noritaka Hamma

Noritaka Hanma

Takeo Takahashi

A process for preparing biotin, characterized in that a compound of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are each hydrogen or benzyl and R.sup.3 is hydrogen or carboxyl, with the proviso that R.sup.1 and R.sup.2 are not simultaneously hydrogen, or a mixture of two or more different compounds of the formula [I] is heated in the presence of an alkanesulfonic acid.

Process for preparing biotin

An improved process for producing a peptide and a cephalosporin which comprises treating a phosphoramide derivative of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are each an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, and A.sub.1 is a peptide residue or a cephalosporin residue, with a phosphorus acid to produce a peptide or a cephalosporin of the formula A.sub.1 --NH.sub.2 wherein A.sub.1 is as hereinbefore defined.

Preparation of peptides and cephalosporins

A process for producing a compound of the formula (I) ##SPC1## wherein R.sub.2 is a hydrogen atom or an ester protective group, which is useful as a precursor for the production of cephalosporin derivatives, comprising reacting a phosphoramide derivative of cephalosporin of the formula (II) ##SPC2## wherein R.sub.1 is a lower alkyl group and R.sub.2 is as defined above, with a phosphorus acid. A further embodiment includes preparing the phosphoramide derivative of cephalosporin of the formula (II) by reactng a compound of the formula (III) ##SPC3## wherein R.sub.1 and R.sub.2 are as defined above, with an acid compound.

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Takarazuka, Japan

Kaoru Maeshima