The war began on February 24th. The first face to face meeting was on the 28th. By March they basically had a treaty worked out with nothing but details remaining to sort out. Then Ukraine chose to abruptly end the talks following the intervention of the West, allegedly Boris John in particular.

There's a somewhat reasonable timeline of the talks themselves, til their end here. [1] But the NYTimes is being a bit disingenuous. The early talks called for the recognition of the independence of Donbas, but under Ukraine. The contested regions were to be given a special status, probably akin to something like Chechnya under Russia or perhaps Puerto Rico under the US. So Ukraine would control these regions, but simultaneously they'd have a significant degree of autonomy and independence. In any case, by March even this issue had been withdrawn.

[1] - https://www.nytimes.com/interactive/2024/06/15/world/europe/...