Diisopropylamine → (r)-2-Bromoisovaleric acid diisopropylamine salt

Participants

Reaction Conditions

Reaction Steps

After continuously adding 16 ml of diisopropylamine to 128.9 g of a methyl t-butyl ether solution of (R)-2-bromoisovaleric acid obtained in Comparative Example 2 was continuously added at −4° C. for 12 min to crystallize, they were stirred successively at 0° C. for 1 hour. Obtained crystals were filtered under a reduced pressure, and then washed with 30 ml of methyl t-butyl ether. Obtained crystals were dried under a reduced pressure to obtain 27.81 g of (R)-2-bromoisovaleric acid diisopropylamine salt (optical purity 98.1% ee, crystallization yield 80%, apparent purity 92.5%, impurity content 2-hydroxy isovaleric acid; 0.31%, bromine content: 4.58%).

Provenance & Evidence