# US 4,394,312 A · Process for preparing rifamycin derivatives

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- Number: US 4,394,312 A
- Document ID: US4394312A
- Status: Granted
- Kind: A
- Application number: 06/373,807
- Filed: 1982-04-30
- Granted: 1983-07-19
- Earliest claimed: 1981-10-15
- Assignees: Korea Advanced Institute of Science and Technology
- Inventors: Moon H. Han; Baik L. Seong
- Web page: https://patentgrep.com/patent/US4394312A

## CPC

- C07D 498/08: Bridged systems
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

3-Dialkylaminomethyl derivatives of rifamycin S is provided by reacting rifamycin S with an iminium salt in an organic solvent. This compound is converted to 3-dialkylaminomethyl derivatives by virtue of ascorbic acid.

## Claims

### Claim 1

A process for preparing 3-dialkylaminomethyl rifamycin S derivatives having the formula: ##STR8## wherein R.sup.1 and R.sup.2 are oxo (.dbd.O); and R.sup.3 and R.sup.4 are methyl, ethyl, propyl, isopropyl, butyl or pentyl, or are connected by methylene bridge where ##STR9## represents piperidine or 3-methylpyrrolidine which process comprises contacting rifamycin S with 1 to 1.5 equimolar amount of an appropriate iminium salt in an organic solvent at a temperature ranging from room temperature to the boiling point of the solvent for a time sufficient to complete the reaction.

### Claim 2 (depends on 1)

The process of claim 1 wherein said solvent is one selected from the group consisting of tetrahydrofuran, dioxane, ethylacetate, benzene, acetonitrile, chloroform, methylene chloride, methanol, ethanol and propanol, and a mixture thereof.

### Claim 3 (depends on 1)

The process of claim 1 wherein said solvent is acetonitrile.

### Claim 4 (depends on 1)

The process of claim 1 wherein the reaction is carried out in two to six hours.