Gradle : Resolving paths for dependent subprojects

Question

I have a project with the below layout:

-RootProject
   -projects
      -sample1
         -build.gradle
      -sample2
         -build.gradle
      -sample3
         -build.gradle
-settings.gradle
-build.gradle

In the RootProject build.gradle looks as below:

include 'sample1'
include 'sample2'
include 'sample3'

I'm able to build the sample1, sample2, sample3 projects. The requirement I have is sample2 and sample3 depend on sample1. For that reason I have added in sample2, sample3 subprojects build.gradle files as below:

model {
  ...........
  ...........
  dependencies {
        compile project(':sample1')
  }
}

On gradle build getting below error:

* What went wrong:
A problem occurred configuring project ':sample2'.
> The following model rules could not be applied due to unbound inputs and/or subjects:

    dependencies { ... } @ projects/sample2/build.gradle line 30, column 5
      subject:
        - dependencies Object [*]

  [*] - indicates that a model item could not be found for the path or type.