Is the word comprou the same in Brazilian and European Portuguese?

Yes.

The word "comprou" is identical in both Brazilian and Continental Portuguese in terms of spelling, grammar (it is the third-person singular, preterite indicative of the verb comprar), and meaning ("bought"). The only difference lies in pronunciation. Brazilian Portuguese tends to have more open vowels and a syllable-timed rhythm, making the diphthong in "comprou" sound clearer and more melodic. Continental Portuguese is more stress-timed and features vowel reduction, which can make the pronunciation sound more compressed or "closed" to a Brazilian ear.

Brazilian Portuguese Examples

1. Ele comprou um carro novo. (He bought a new car.)
2. Ela comprou um celular novo. (She bought a new cell phone.)
3. Ele comprou um doce de leite. (He bought a milk candy.)
4. O menino comprou um brinquedo. (The boy bought a toy.)
5. Ela comprou uma bala de menta. (She bought a mint candy.)

Continental Portuguese Examples

1. Ele comprou um carro novo. (He bought a new car.)
2. Ela comprou um telemóvel novo. (She bought a new mobile phone.)
3. Ele comprou um doce de leite. (He bought a milk candy.)
4. O menino comprou um brinquedo. (The boy bought a toy.)
5. Ela comprou um rebuçado de menta. (She bought a mint candy.)