cdcl 3 u03b4 2 576 3h s u03b4 3 189 2h t u03b4 3 841 2h t u03b4 4 3 1h bs u03b4 7 022 1h m u03b4 7 1 1h t u03b4 8 46 1h d 9 hydroxy 3 2 chloroethyl 2 methyl 4h pyrido 1 2 a pyrimidin 4 one 235 parts was added into methanol 1300 parts which was then acidified and the ph was adjusted with 10 13 methanolic hcl 500 part from 0 1 the reaction mass was concentrated into a thick slurry filtered and washed with chilled methanol 100 parts the product was dried at 60 u00b0 c under vacuum 700 mm hg to yield 219 parts of 9 hydroxy 3 2 chloroethyl 2 methyl 4h pyrido 1 2 a pyrimidin 4 one with hplc purity above 98 1 h nmr d 2 o u03b42 414 3h s u03b4 2 723 2h t u03b4 3 904 2h t u03b4 7 602 1h m u03b4 7 747 1h d u03b4 8 732 1h d the use of the terms u201c a u201d and u201c an u201d and u201c the u201d and similar referents in the context of describing the invention especially in the context of the following claims are to be construed to cover both the singular and the plural unless otherwise indicated herein or clearly contradicted by context the terms u201c comprising u201d u201c having.