There are provided novel compounds of formula (I) ##STR1## including their 3,4-dihydropyrimidine tautomer form, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, X and n are as defined in the specification, and optical isomers and racemates thereof and pharmaceutically acceptable salts thereof; together with processes for their preparation, compositions containing them and their use in therapy. The compounds are antagonists of N-type neuronal calcium channels useful in the treatment of cerebrovascular ischaemia and pain.

Há compostos fornecidos da novela do ## do ## STR1 da fórmula (I) including seu formulário do tautomer 3,4-dihydropyrimidine, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, X e n são como definidos na especificação, e isomers e racemates óticos disso e pharmaceutically sais aceitáveis disso; junto com processos para sua preparação, composições contendo os e seu uso na terapia. Os compostos são antagonistas do N-tipo canaletas neuronal do cálcio úteis no tratamento do ischaemia e da dor cerebrovascular.