Accurate classification of brain tumors from magnetic resonance imaging (MRI) is important for supporting timely diagnosis and subsequent clinical decision-making. In this study, EnDeC, an enhanced convolutional neural network, was developed for automated multiclass classification of brain MRI images. The Crystal Clean: Brain Tumors MRI Dataset, comprising 21,672 images categorized as glioma, meningioma, pituitary tumor, or normal, was used for model development and evaluation. Following data cleaning and class balancing, 12,264 images were retained for model training. Image preprocessing and augmentation procedures, including resizing, noise injection, and rotation, were applied. An efficient input pipeline was implemented using the TensorFlow tf.data application programming interface, with caching and prefetching incorporated to reduce input/output bottlenecks during training. The EnDeC architecture was constructed using successive convolutional and pooling layers for hierarchical feature extraction, followed by fully connected layers for multiclass classification. Model performance was evaluated using accuracy, precision, recall, F1-score, and specificity. Average values of 99.60%, 99.18%, 99.19%, 99.18%, and 99.74% were obtained for these metrics, respectively. Among the evaluated optimization configurations, the Adam optimizer yielded the highest test accuracy of 99.20%. These findings demonstrate that discriminative imaging features associated with multiple brain tumor categories can be effectively learned using the proposed convolutional neural network framework. Nevertheless, validation using independent, patient-level, multi-institutional datasets is required before clinical applicability can be established. The proposed approach provides a computational framework for automated brain MRI classification and may support the further development of computer-aided diagnostic systems for brain tumor assessment.