The phrase "were in vain" is often used to express that one's efforts or actions were unsuccessful or futile. There are many synonyms that can be used in place of this phrase to convey a similar message, such as "proved fruitless", "were for naught", "had no effect", "were unsuccessful", "came to nothing", "failed to yield results", and "were pointless". These phrases can be used interchangeably depending on the tone and context of the sentence. Using synonyms can add variety to one's writing and help to prevent repetition, while still conveying the same message and emotion as the original phrase.