Sodium Hydroxide → 3-Amino-6-bromopyrazine-2-carboxylic acid

Temperature

50 °C

Methy 3-amino-6-bromopyrazine-2-carboxylate (1.4 Kg), 5N NaOH solution (5.6 L) and methanol (8.4 L) were charged into reactor. The resulting suspension was warmed at 50° C. for 3 hours with vigorous stirring. The mixture was analysed for reaction completion. The mixture was cooled to 25° C. and the solids were collected by filtration. Filter cake was washed with water (1 L). The resultant solids were suspended in water (5 L) and pH value of this suspension was adjusted to 3 by adding 6 N HCl solution. The acidic solution was vigorously stirred at 25° C. for 48 h. During this period, pH value was checked, additional acid was charged if pH value >3. The suspension was filtered to collect a yellow-brown solid, which was dried in oven at 40° C. under a flow of N2. The crude subtitle material was used in the next step.

1. customThe mixture was analysed for reaction completion
2. temperatureThe mixture was cooled to 25° C.
3. filtrationthe solids were collected by filtration
4. filtrationFilter cake
5. washwas washed with water (1 L)
6. additionby adding 6 N HCl solution
7. waitDuring this period
8. additionadditional acid was charged if pH value >3
9. filtrationThe suspension was filtered
10. customto collect a yellow-brown solid, which
11. dry with materialwas dried in oven at 40° C. under a flow of N2

ORD record

ord-11dc1b5c3a2e4e9fa9a07730fa577dae

Source dataset

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08198285B2