CS267945B1

CS267945B1 - Method of 5-bromo-6-amino-1-methyluracil preparation

Info

Publication number: CS267945B1
Application number: CS877880A
Authority: CS
Inventors: Ladislav Ing Csc Stibranyi; Miroslav Ing Csc Veverka; Jan Ing Csc Jendrichovsky
Original assignee: Stibranyi Ladislav; Veverka Miroslav; Jendrichovsky Jan
Priority date: 1987-11-04
Filing date: 1987-11-04
Publication date: 1990-02-12
Also published as: CS788087A1

Abstract

Predmetom rleSenia Je epoeob přípravy 5-bróm-6-am±no-1-metyluraoilu, ktorý je medziprodúktom výroby teobrominu, reakciou brómu vo vodě 2 6-amino-1 -metyluraoilom pri zvýženej teplote. Pri tomto převedení je úplné potlačený vznik dlbrómderlvátu, výhodou je tiež jednoduché prevedenie.The object of the present invention is to prepare 5-bromo-6-amino-1-methyluraoil, which is is the intermediate product of theobromine production, bromine in water reaction with 6-amino-1-methyluraoil at elevated temperature. At this the conversion is a complete suppression of the formation of bromofluoride, the advantage is also simple design.

Description

en 267 9 ^ 5 Bi

The present invention provides a process for the preparation of 5-bromo-6-amino-1-methylureail

II

HN

CSU (I), which is an intermediate for the preparation of purine bases.

In the meantime, the subject compound was prepared by the 6-amino-1-methylurea silicon II reagent

(II), with bromine in water at a temperature of about 20 ° C (Barker, Luthy: J. Chem. Soo, 1965, 917-920 or in ootic acid (Wojoieohowski J., Polish Patent 42,976). disposing of bromine in an alkali bile environment (2. AO 267082), which is characterized by a reduced content of dibromo derivative;

According to the present invention, the present compound of Formula 1 is prepared from 6-amino-1-methyluriloxide II and bromine in an aqueous medium at a temperature of 50-100 ° C, using a llamatic ratio of bromine to 6-amino-1-methyluraoil sample II 1: 1 to 2: 1. The advantage of this embodiment of the reaction is the rapid development, at a temperature of 50-100 ° C, the formation of a dibromo derivative is completely suppressed. The reaction is slightly exothermic, sufficient to maintain the reaction temperature, allowing the reaction to be carried out in an adiabatic continuous manner. In one aspect, the invention is illustrated by way of example only without being taught by the art. Example 1

A mixture of 140 g (1.0 mol) of 6-amino-1-methyluraoil in 1000 ml of water is heated to 50 ° C. Briefly, 6 L, 2 mL (192 g, 1.2 mole) of bromine was fed under vigorous stirring over 20 minutes. The temperature is automatically raised to 80 [deg.] C. with the addition. The product is filtered off, washed with 100 ml of water and dissolved in 500 ml of 2M NaOH solution. Charcoal is added, filtered and the filtrate is acidified with 60 ml of ootic acid. The product precipitated out of the solution, which was filtered off with suction, washed with 200 ml of water, 200 ml of ethanol and dried at 105 ° C. 162 g (73%) of 5-bromo-6-amino-1-methyluracil are obtained, mp 283-286 ° C.

Claims

2 EN 267 9 ^ 5 B1 tab. 1, the reaction conditions of this embodiment are given in Br 2 (mol) MAU 1 (mol) T (° C) Coated Yield Heat-vein 1 1 1 75-80 A 67.2 281-285 2 1.5 1 75-80 B 78, 1 280-285 3 2.0 1 75-80 B 41.3 281-284 4 0.12 0.1 80 B 72.0 280-285 5 0.08 o, o4 90-100 A 63.0 283- 286 n - 1 - 6-Amino-1-methyluraoil Λ test product - the product was purified by sodium salt B - the product was isolated without purification of sodium salt

1, Preparation of 5-bromo-6-amino-1-methylureail

(I), 6-amino-1 ' -methyluraoil H0 II

(II) and bromine in an aqueous medium, characterized in that the reaction is carried out at a temperature of 50-100 ° C,

2. A method according to claim 1, wherein a molar ratio of bromine to 6-amino-1-methyluroyl of formula IX is 1: 1 to 2: 1.