C. Kashima et al., NEW FACILE ALKOXYCARBONYLATING AGENT, ALKYL PYRAZOLE-1-CARBOXYLATES -THE PREPARATION AND THE UTILITIES, Tetrahedron, 54(49), 1998, pp. 14679-14688
Alkyl pyrazole-1-carboxylates (2), which were readily prepared from al
kyl chloroformate or carbazate in good yields, were provided as the ne
w facile alkoxycarbonylating agents toward the Grignard reagents for t
he synthesis of one carbon higher carboxylic esters. Also amines were
alkoxycarbonylated by 2 to produce the corresponding urethanes even in
an aqueous medium. Benzyl 3,5-dimethylpyrazole-1-carboxylate (2d) cou
ld be utilized for the Cbz-protection of amino acids and esters in goo
d yield without any racemization. (C) 1998 Elsevier Science Ltd. All r
ights reserved.