Process for preparing benzyl carbazates

US6160160A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Edwin Ritzer · Leverkusen, DE
• Robert Sollner · Jenbach, AT
• Claus Dreisbach
• Frank Jelitto · Bensberg, DE

Key dates

• Filing date: Aug 6, 1999
• Grant date: Dec 12, 2000
• Expiry date: Aug 6, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C281/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for preparing optionally substituted benzyl carbazates of formula (I) ##STR1## wherein each R.sup.1 independently represents C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, di(C.sub.1 -C.sub.4 -alkyl)amino, nitro, halogen, hydroxyl, the group X-R.sup.3, wherein X represents O or S and R.sup.3 represents straight-chain or branched C.sub.1 -C.sub.4 -alkyl, the group COOR.sup.4, wherein R.sup.4 represents C.sub.1 -C.sub.4 -alkyl, the group NR.sup.5 R.sup.6, wherein R.sup.5 and R.sup.6 independently represent C.sub.1 -C.sub.4 -alkyl, or a C.sub.3 -C.sub.6 -cycloalkyl group that is optionally substituted by straight-chain or branched C.sub.1 -C.sub.4 -alkyl groups, and PA1 n is an integer from 0 to 5, by reacting a dialkyl carbonate with an optionally substituted benzyl alcohol in the presence of a catalyst, separating off the resulting reaction mixture from the catalyst, and subsequently reacting the separated reaction mixture with hydrazine hydrate.