3,4-Dihydro-2H-pyrido[1,2-a]pyrimidin-2-one

Abstract

[5439-14-5] C8H8N2O (MW 148.16) InChI = 1S/C8H8N2O/c11-8-4-6-10-5-2-1-3-7(10)9-8/h1-3,5H,4,6H2 InChIKey = XQIOBBHIEUGFCI-UHFFFAOYSA-N (synthesis of esters and amides from carboxylic acids; glycosylation) Physical Data: mp 155–156 °C; mp (HCl salt) 284–285.5 °C (dec); mp (HBr salt) 299–300 °C (dec); mp (HI salt) 263–264 °C (dec). Solubility: sol MeOH, EtOH, H2O. Form Supplied in: both the free base and salts are obtained as colorless solids. Analysis of Reagent Purity: the reagent has a betaine-like structure and behaves as a salt in terms of the reagent's solubility. The literature reports various melting points values for both the anhydrous and hydrated forms of the reagent but the conditions used to determine melting point have been shown to be critical and care must be exercised if this property is to be used as a measure of reagent purity.1 Preparative Methods: is prepared by reaction of 2-aminopyridine with either Acrylic Acid itself or an equivalent (2-bromo- or 2-iodopropionic acid, Methyl Acrylate, ethyl 2-bromopropionate, β-Propiolactone).1, 2 Purification: the free base and salts are readily recrystallized from MeOH–Et2O.1 Handling, Storage, and Precautions: the reagent may be dried over P2O5 in vacuo (135 °C/17 mmHg).