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

Participants

Reaction Steps

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.

Provenance & Evidence