Hydrochloric Acid → 1,4,5,6-Tetrahydropyrimidine-5-carboxylic acid hydrochloride

Pyrimidine-5-carboxylic acid (5.0 g, 40 mmol) was suspended in a mixture of 150 ml water and concentrated hydrochloric acid (4.0 g, 40.5 mmol). The mixture was hydrogenated at 26 psig over 1.0 g Pd-on-carbon 10% in a Parr hydrogenator for 3 h. The suspension was filtered and the filter rinsed twice with hot water (20 ml). The filtrate was evaporated in vacuo to give 6.11 g yellow oil (92%). The oil was crystallized from anhydrous methanol/tetrahydrofuran (THF) to give 5.77 g (87%) white crystals in two crops. 300 MHz nmr indicated product.

1. filtrationThe suspension was filtered
2. washthe filter rinsed twice with hot water (20 ml)
3. customThe filtrate was evaporated in vacuo

ORDレコード

ord-981f88bd9a6c4cc4a6a774037a94f6a5

出典データセット

uspto-grants-1992_12

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05175166