Gradle DSL method not found android()

I open a friend project at Android Studio, my AS version is greater than his.

Here is the error:

Error:(27, 0) Gradle DSL method not found: 'android()'
Possible causes:The project 'firstapp' may be using a version of Gradle that does not contain the method.
Open Gradle wrapper file        The build file may be missing a Gradle plugin.
Apply Gradle plugin.

Here is the build.gradle:

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.0-alpha1'
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.4'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}
allprojects {
    repositories {
        jcenter()
        mavenCentral()
        maven {
            url 'https://oss.sonatype.org/content/repositories/snapshots/'
        }
    }
}
task clean(type: Delete) {
    delete rootProject.buildDir
}

android {
    compileSdkVersion 19
    buildToolsVersion '21.0.0'
}
dependencies {
}

How can i get this fixed?